This article is funded by Beijing Haidian Innovation and Transformation Project, HDCXZHKC2021212.

This study adhered to the tenets of the Declaration of Helsinki. The study protocol was approved by the Institutional Review Board of Peking University Third Hospital. It should be noted that the novel procedure here is the step of rotating the IOL. The inclusion criteria are cataract patients over 50 years of age willing to undergo cataract surgery in Peking University Third Hospital. The exclusion criteria are the presence of eye diseases that may affect the stability of the suspensorium and capsular bag, such as pathologic myopia, glaucoma, pseudoexfoliation syndrome, uveitis, subluxation of the lens including Marfan syndrome, Marchesani syndrome, and homocystinuria.
1. Surgery preparation
<ol>
	<li>Patient preparation
	<ol>
		<li>Use 0.5% levofloxacin eye drops four times per day 3 days before surgery. Administer topical anesthetic eye drops of 0.4% oxybuprocaine hydrochloride three times per 5 min before the surgery (see Table of Materials). 
		NOTE: Patients&#39; pupils become dilated with compound tropicamide eye drops (0.5% tropicamide and 0.5% phenylephrine hydrochloride) 1 h before surgery.</li>
	</ol>
	</li>
	<li>Equipment settings
	<ol>
		<li>Ensure the following settings for the phacoemulsification device system (see Table of Materials): 30%-95% torsional nucleus chop, 90 cm bottle height, 260-450 mm Hg vacuum, and 36 cc/min aspiration flow rate.</li>
	</ol>
	</li>
</ol>
2. Rotating using the irrigation and aspiration (I/A) system
<ol>
	<li>Corneal incision
	<ol>
		<li>Make a 3.2 mm limbal incision at the steepest meridian using a 3.2 mm slit blade (see Table of Materials). A &#34;Z&#34;-shaped multiplanar corneal incision is preferred. First, create a 0.3 mm deep groove perpendicular to the corneal surface and insert the blade into the groove with its tip tangentially directed to the corneal surface, thereby creating a tunnel through the clear cornea into the anterior chamber.</li>
		<li>Create a 0.8 mm subsidiary incision 90&#176; anti-clockwise using a 20 G side port microvitreoretinal (MVR) knife (see Table of Materials).</li>
	</ol>
	</li>
	<li>Phacoemulsification
	<ol>
		<li>Open the capsule with a continuous curvilinear capsulorhexis using Utrata capsulorhexis forceps (see Table of Materials) under viscoelastic conditions.</li>
		<li>Perform cortical-cleaving hydrodissection by placing a blunt-tipped cannula with balanced salt solution (BSS) under the anterior capsule flap, carefully lifting the capsular, and injecting BSS in a radial direction, to separate the cortex from the posterior capsule.</li>
		<li>Perform hydrodelineation by injecting BSS into the substance of the nucleus to separate the harder nucleus from the peripheral softer nucleus.</li>
		<li>Under the mode of &#34;chop&#34;, bury the phaco tip into the center of the nucleus and insert the phaco tip (see Table of Materials) under the anterior capsule flap, cracking the nucleus into two pieces using Sinskey hook (see Table of Materials). Repeat this step to create multiple small wedges of the nucleus for phacoemulsification.</li>
	</ol>
	</li>
	<li>Irrigation and Aspiration (I/A)
	<ol>
		<li>Modulate the machine in &#34;cortex&#34; mode. Use the I/A tip (see Table of Materials) to accomplish cortical cleanup. Remove the soft epinucleus and peripheral cortical material.</li>
	</ol>
	</li>
	<li>IOL insertion
	<ol>
		<li>Fill the capsule bag and anterior chamber with viscoelastics (see Table of Materials). Load a foldable single-piece IOL (see Table of Materials) into an injector cartridge prefilled with viscoelastic.</li>
		<li>Introduce the tip of the injector through the incision and insert the IOL by pushing the tail of the injector, with the anterior haptic spreading into the capsular bag. Place the posterior haptic under the anterior capsule using the tip of the injector.</li>
	</ol>
	</li>
	<li>Rotating the IOL and removing the viscoelastic
	<ol>
		<li>Use the I/A tip to remove the viscoelastic from the anterior chamber. During this procedure, rotate the IOL clockwise at least 360&#176; using the I/A tip with slight posterior pressure.</li>
		<li>Aspirate the residual fragments and viscoelastic in the capsular bag by inserting the I/A tip behind the optic part of the IOL.</li>
	</ol>
	</li>
</ol>
3. Rotating using IOL hooks
<ol>
	<li>The steps before insertion of the IOL are the same as the first four steps (2.1-2.4) above. In this method, after the IOL is inserted into the capsular bag, use a Fenzl hook (see Table of Materials) to rotate the IOL clockwise at least 360&#176; and slide the IOL in the capsular bag from side to side, putting slight pressure on the posterior capsule at the same time.</li>
</ol>
4. Follow-up procedures
<ol>
	<li>Instill BSS from the paracentesis incision using a blunt-tipped cannula to reform the anterior chamber.</li>
	<li>Inject BSS into both sides of the corneal tunnel incision. If the incision leaks, the wound should be sutured with a 10-0 nylon suture.</li>
</ol>

Preventing Posterior Capsular Opacification Through IOL Rotation in Cataract Surgeries

<ol>
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C., Hadayer, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Continuous+curvilinear+capsulorhexis+-+a+practical+review.">Continuous curvilinear capsulorhexis - a practical review.</a> Seminars in Ophthalmology. 37 (5), 583-592 (2022).</li><li>Wormstone, I. M., Wormstone, Y. M., Smith, A. J. O., Eldred, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Posterior+capsule+opacification:+What's+in+the+bag.">Posterior capsule opacification: What's in the bag.</a> Progress in Retinal and Eye Research. 82, 100905 (2021).</li><li>Wu, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+importance+of+the+epithelial+fibre+cell+interface+to+lens+regeneration+in+an+in+vivo+rat+model+and+in+a+human+bag-in-the-lens+(BiL)+sample.">The importance of the epithelial fibre cell interface to lens regeneration in an in vivo rat model and in a human bag-in-the-lens (BiL) sample.</a> Experimental Eye Research. 213, 108808 (2021).</li><li>Darian-Smith, E., Safran, S. G., Coroneo, M. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lens+epithelial+cell+removal+in+routine+phacoemulsification:+is+it+worth+the+bother.">Lens epithelial cell removal in routine phacoemulsification: is it worth the bother.</a> American Journal of Ophthalmology. 239, 1-10 (2022).</li><li>Leydolt, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Posterior+capsule+opacification+with+two+hydrophobic+acrylic+intraocular+lenses:+3-year+results+of+a+randomized+trial.">Posterior capsule opacification with two hydrophobic acrylic intraocular lenses: 3-year results of a randomized trial.</a> American Journal of Ophthalmology. 217, 224-231 (2020).</li><li>Ursell, P. G., Dhariwal, M., O'Boyle, D., Khan, J., Venerus, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=5+year+incidence+of+YAG+capsulotomy+and+PCO+after+cataract+surgery+with+single-piece+monofocal+intraocular+lenses:+a+real-world+evidence+study+of+20,763+eyes.">5 year incidence of YAG capsulotomy and PCO after cataract surgery with single-piece monofocal intraocular lenses: a real-world evidence study of 20,763 eyes.</a> Eye. 34 (5), 960-968 (2020).</li><li>Apple, D. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Eradication+of+posterior+capsule+opacification:+documentation+of+a+marked+decrease+in+Nd:YAG+laser+posterior+capsulotomy+rates+noted+in+an+analysis+of+5416+pseudophakic+human+eyes+obtained+postmortem.">Eradication of posterior capsule opacification: documentation of a marked decrease in Nd:YAG laser posterior capsulotomy rates noted in an analysis of 5416 pseudophakic human eyes obtained postmortem.</a> Ophthalmology. 108 (3), 505-518 (2020).</li><li>Wormstone, I. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+lens+epithelial+cell+proliferation+in+a+protein-free+medium.">Human lens epithelial cell proliferation in a protein-free medium.</a> Investigative Ophthalmology &amp; Visual Science. 38 (2), 396-404 (1997).</li><li>Fisus, A. D., Findl, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capsular+fibrosis:+a+review+of+prevention+methods+and+management.">Capsular fibrosis: a review of prevention methods and management.</a> Eye. 34 (2), 256-262 (2020).</li><li>Eldred, J. A., Zheng, J., Chen, S., Wormstone, I. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+in+vitro+human+lens+capsular+bag+model+adopting+a+graded+culture+regime+to+assess+putative+impact+of+IOLs+on+PCO+formation.">An in vitro human lens capsular bag model adopting a graded culture regime to assess putative impact of IOLs on PCO formation.</a> Investigative Ophthalmology &amp; Visual Science. 60 (1), 113-122 (2019).</li><li>Joshi, R. S., Chavan, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rotation+versus+non-rotation+of+intraocular+lens+for+prevention+of+posterior+capsular+opacification.">Rotation versus non-rotation of intraocular lens for prevention of posterior capsular opacification.</a> Indian Journal of Ophthalmology. 67 (9), 1428-1432 (2019).</li><li>Liu, X., Cheng, B., Zheng, D., Liu, Y., Liu, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+anterior+capsule+polishing+in+residual+lens+epithelial+cell+proliferation.">Role of anterior capsule polishing in residual lens epithelial cell proliferation.</a> Journal of Cataract and Refractive Surgery. 36 (2), 208-214 (2010).</li><li>Boyce, J. F., Bhermi, G. S., Spalton, D. J., El-Osta, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mathematical+modeling+of+the+forces+between+an+intraocular+lens+and+the+capsule.">Mathematical modeling of the forces between an intraocular lens and the capsule.</a> Journal of Cataract and Refractive Surgery. 28 (10), 1853-1859 (2002).</li><li>Spalton, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Posterior+capsule+opacification:+have+we+made+a+difference.">Posterior capsule opacification: have we made a difference.</a> The British Journal of Ophthalmology. 97 (1), 1-2 (2013).</li><li>Wang, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+modification+of+intraocular+lens+with+hydrophilic+poly(sulfobetaine+methacrylate)+brush+for+posterior+capsular+opacification+prevention.">Surface modification of intraocular lens with hydrophilic poly(sulfobetaine methacrylate) brush for posterior capsular opacification prevention.</a> Journal of Ocular Pharmacology and Therapeutics. 37 (3), 172-180 (2021).</li><li>Liu, S., Zhao, X., Tang, J., Han, Y., Lin, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drug-eluting+hydrophilic+coating+modification+of+intraocular+lens+via+facile+dopamine+self-polymerization+for+posterior+capsular+opacification+prevention.">Drug-eluting hydrophilic coating modification of intraocular lens via facile dopamine self-polymerization for posterior capsular opacification prevention.</a> ACS Biomaterials Science &amp; Engineering. 7 (3), 1065-1073 (2021).</li><li>Sureshkumar, J., Haripriya, A., Muthukkaruppan, V., Kaufman, P. L., Tian, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cytoskeletal+drugs+prevent+posterior+capsular+opacification+in+human+lens+capsule+in+vitro.">Cytoskeletal drugs prevent posterior capsular opacification in human lens capsule in vitro.</a> Graefes Archive for Clinical and Experimental Ophthalmology. 250 (4), 507-514 (2012).</li><li>Eid, A. M., Abd-Elhamid Mehany Elwan, S., Sabry, A. M., Moharram, H. M., Bakhsh, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+technique+of+pneumatic+posterior+capsulorhexis+for+treatment+and+prevention+of+posterior+capsular+opacification.">Novel technique of pneumatic posterior capsulorhexis for treatment and prevention of posterior capsular opacification.</a> Journal of Ophthalmology. 2019, 3174709 (2019).</li><li>Hollick, E. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+polymethylmethacrylate,+silicone,+and+polyacrylic+intraocular+lenses+on+posterior+capsular+opacification+3+years+after+cataract+surgery.">The effect of polymethylmethacrylate, silicone, and polyacrylic intraocular lenses on posterior capsular opacification 3 years after cataract surgery.</a> Ophthalmology. 106 (1), 49-54 (1999).</li><li>Ursell, P. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Relationship+between+intraocular+lens+biomaterials+and+posterior+capsule+opacification.">Relationship between intraocular lens biomaterials and posterior capsule opacification.</a> Journal of Cataract and Refractive Surgery. 24 (3), 352-360 (1998).</li><li>Nishi, O., Nishi, K., Wickstrom, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preventing+lens+epithelial+cell+migration+using+intraocular+lenses+with+sharp+rectangular+edges.">Preventing lens epithelial cell migration using intraocular lenses with sharp rectangular edges.</a> Journal of Cataract and Refractive Surgery. 26 (10), 1543-1549 (2000).</li><li>Li, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+AcrySof+versus+silicone+or+polymethyl+methacrylate+intraocular+lens+on+posterior+capsule+opacification.">Effect of AcrySof versus silicone or polymethyl methacrylate intraocular lens on posterior capsule opacification.</a> Ophthalmology. 115 (5), 830-838 (2008).</li><li>Maedel, S., Evans, J. R., Harrer-Seely, A., Findl, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraocular+lens+optic+edge+design+for+the+prevention+of+posterior+capsule+opacification+after+cataract+surgery.">Intraocular lens optic edge design for the prevention of posterior capsule opacification after cataract surgery.</a> The Cochrane Database of Systematic Reviews. 8 (8), (2021).</li><li>Schartmuller, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Posterior+capsule+opacification+and+Nd:YAG+laser+rates+with+two+hydrophobic+acrylic+single-piece+IOLs.">Posterior capsule opacification and Nd:YAG laser rates with two hydrophobic acrylic single-piece IOLs.</a> Eye. 34 (5), 857-863 (2020).</li><li>Patel, C. K., Ormonde, S., Rosen, P. H., Bron, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Postoperative+intraocular+lens+rotation:+a+randomized+comparison+of+plate+and+loop+haptic+implants.">Postoperative intraocular lens rotation: a randomized comparison of plate and loop haptic implants.</a> Ophthalmology. 106 (11), 2190-2195 (1999).</li><li>Zhu, X., Meng, J., He, W., Rong, X., Lu, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+the+rotational+stability+between+plate-haptic+toric+and+C-loop+haptic+toric+IOLs+in+myopic+eyes.">Comparison of the rotational stability between plate-haptic toric and C-loop haptic toric IOLs in myopic eyes.</a> Journal of Cataract and Refractive Surgery. 46 (10), 1353-1359 (2020).</li><li>Tassignon, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Elimination+of+posterior+capsule+opacification.">Elimination of posterior capsule opacification.</a> Ophthalmology. 127, S27-S28 (2020).</li></ol>

All authors have no conflict of interest.

There are some benefits to this method. Firstly, residual LECs in the capsule bag were reduced further, especially those in the equatorial area, and the possibility of PCO occurrence was reduced rationally. Secondly, a reduced possibility of PCO means a lower rate of Nd:YAG laser treatment, providing the opportunity to maintain the integrity of the capsule bag and effective lens positions and functions. Thirdly, this method can be achieved with available instruments in cataract surgery without additional preparation. In ...

Cataracts are the most common cause of blindness worldwide, characterized by a clouding of the lens. The only means of treating cataracts is surgical intervention by removing the opaque lens, which restores high visual quality. However, a secondary reduction of visual quality, termed posterior capsule opacification (PCO), develops in 20%-40% of patients within 2 to 5 years after surgery1. This article introduces a method to further remove residual lens epithelial cells (LECs) left in the capsular bag in cataract surgery by rotating the intraocular lens (IOL) to prevent PCO.
PCO is a process caused by LECs, which are inevitably left in the capsular bag following cataract surgery and then begin to proliferate and migrate2. During phacoemulsification, a capsular bag is generated by continuous curvilinear capsulorhexis in the anterior capsule, which comprises a part of the anterior capsule, the equatorial capsule, and the entire posterior capsule2,3. In most patients, an IOL is implanted into the capsular bag. A transparent capsular bag, especially the posterior capsule, permits the light to transmit into the eyes, which is necessary for good postoperative visual quality4. A proportion of LECs are usually still attached to the capsular bag. As a reaction to the surgical trauma and a foreign body response toward IOLs, the residual epithelial cells start to proliferate and occupy first the remaining part of the anterior capsule, and then all available surfaces, including the surface of IOL and, most importantly, the previously acellular posterior capsule4. Subsequently, cells continue to divide, ultimately covering the entire posterior capsule and affecting the visual axis. The following changes, including fibrosis and regenerative form5, can cause significant visual impairment6. 
PCO that affects visual acuity can be treated with capsulotomy of the posterior capsule, usually by a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser and sometimes a surgical procedure4. Recent studies report that the incidence of Nd:YAG capsulotomy for treating PCO 3 years after surgery is between 5% and 20%7,8. However, this procedure can break the normal posterior capsular morphology and wrinkle the posterior capsule, thus likely affecting the position of IOLs, which is unfavorable to the long-term visual outcome of IOLs, especially multifocal IOLs, and toric IOLs6. Advances in surgical procedures, IOL design, the pharmacological inhibition of LEC proliferation, and the induction of LEC apoptosis have been confirmed useful in preventing PCO, most of which target the LECs9. 
LECs are normally distributed over the inner side of the anterior lens capsule in single-layer form1. LECs distributed in the area around the equatorial lens are the natural site of division, which is known as the germinative zone, while the dividing cells are also observed on the anterior capsule10,11. It has also been shown that equatorial cells can proliferate and migrate in the posterior capsule12. Residual LECs in the capsular bag are responsible for PCO. If LECs in the germinative zone are cleared as much as possible during cataract surgery, the possibility of PCO occurring postoperatively decreases as a consequence. As far as it is known, routine phacoemulsification does not include a procedure to remove equatorial LECs. In a study in India, the author proposed that rotation of the IOL by a Sinskey hook13 in the capsular bag decreases PCO and Nd:YAG capsulotomy rate.
Here, we introduced a method by rotating the IOL using an irrigation/aspiration (I/A) tip in the capsular bag to prevent PCO in cataract surgeries. The rationale of this method relies on the mechanical contact between the IOL and the capsular bag, especially the equatorial area, to remove residual LECs. Compared with treating PCO using Nd:YAG capsulotomy, the prevention of PCO maintains the integrity of the posterior capsule and the correct position of IOLs. Additionally, this method is cost-effective and requires no extra tools, which applies to cataract phacoemulsification and IOL implantation. Different from anterior capsule polishing, which is conducted using an I/A tip in the polishing mode of the phaco system6,14, the rotation of the IOL is conducted after the IOL implantation and is supposed to further remove visible lens matter (cortex) and cells.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>20 G Sideport MVR Knife</td>
			<td>BVI</td>
			<td>378231</td>
			<td>To make corneal incision</td>
		</tr>
		<tr>
			<td>3.2 mm Slit Blade</td>
			<td>BVI</td>
			<td>378232</td>
			<td>To make corneal incision</td>
		</tr>
		<tr>
			<td>Balanced salt solution</td>
			<td>Xingqi</td>
			<td>H19991142</td>
			<td>Compound electrolyte intraocular irrigating solution</td>
		</tr>
		<tr>
			<td>Centurion vision system&#160;</td>
			<td>Alcon Laboratories</td>
			<td>8065753057</td>
			<td>The Centurion Vision System is indicated for emulsification, separation, irrigation, and aspiration of cataracts, residual cortical material and lens epithelial cells, vitreous aspiration and cutting associated with anterior vitrectomy, bipolar coagulation, and intraocular lens injection.</td>
		</tr>
		<tr>
			<td>Compound tropicamide eye drops</td>
			<td>Xingqi</td>
			<td>Zhuobian</td>
			<td>To dilate the pupils before the surgery</td>
		</tr>
		<tr>
			<td>Disposable sterile irrigator</td>
			<td>WEGO</td>
			<td>100038404339</td>
			<td>To complete hydrodissection and hydrodelineation&#160;</td>
		</tr>
		<tr>
			<td>Fenzl lens insertion hook and manipulator</td>
			<td>Belleif</td>
			<td>IF-8100</td>
			<td>IOL positioning hook</td>
		</tr>
		<tr>
			<td>Levofloxacin eye drops</td>
			<td>Santen</td>
			<td>Cravit</td>
			<td>To prevent ocular infection before the surgery</td>
		</tr>
		<tr>
			<td>Mini-flared Kelman tip 30DG</td>
			<td>Alcon Laboratories</td>
			<td>8065750852</td>
			<td>To complete phacoemulsification</td>
		</tr>
		<tr>
			<td>One piece intraocular Lens</td>
			<td>Zeiss</td>
			<td>AT TORBI 709M</td>
			<td>Intraocular lens</td>
		</tr>
		<tr>
			<td>Oxybuprocaine hydrochloride</td>
			<td>Santen</td>
			<td>Benoxil</td>
			<td>Topical anesthesia</td>
		</tr>
		<tr>
			<td>Phaco handpiece</td>
			<td>Alcon Laboratories</td>
			<td>8065751761</td>
			<td>To complete phacoemulsification&#160;</td>
		</tr>
		<tr>
			<td>Sinskey hook</td>
			<td>Belleif</td>
			<td>IF-8013</td>
			<td>For chop</td>
		</tr>
		<tr>
			<td>Ultraflow II I/A tip</td>
			<td>Alcon Laboratories</td>
			<td>8065751795</td>
			<td>To complete irrigation and aspiration&#160;</td>
		</tr>
		<tr>
			<td>Utrata capsulorhexis forceps</td>
			<td>Belleif</td>
			<td>IF-3003C</td>
			<td>To complete continuous circular capsulorhexis</td>
		</tr>
		<tr>
			<td>Viscoelastics/Medical sodium hyaluronate gel</td>
			<td>Bausch&#38;lomb</td>
			<td>iviz</td>
			<td>Maintaining the anterior chamber and capsular bag</td>
		</tr>
	</tbody>
</table>

rotating the intraocular lens to prevent posterior capsular opacification in cataract surgeries

Posterior capsule opacification (PCO) is a common postoperative complication of extracapsular cataract surgery, which is caused by the proliferation and migration of lens epithelial cells and can affect long-term visual outcomes significantly. The most effective treatment for PCO is neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy; however, this treatment is associated with posterior segment complication and can break the stability of capsular bag, affecting the position and function of trifocal or toric intraocular lenses (IOLs). Advances in surgical procedures, IOL design, and pharmacy have reduced the rate of PCO in recent years, concentrating on the inhibition of proliferative lens epithelial cells (LECs). This protocol aimed to clear LECs more thoroughly during phacoemulsification and IOL implantation. The first several steps, including clear corneal incision, continuous circular capsulorhexis, hydrodissection, hydrodelineation, and phacoemulsification, were completed as conventional procedures. After placing the IOL into the capsular bag, rotation of the IOL by at least 360&#176; was performed using an irrigation/aspiration tip or a hook, with slight stress on the posterior capsule. Some residuals occurred in the originally transparent capsular bag after rotation of the IOLs. Then, these materials and the viscoelastic were cleared completely using an irrigation/aspiration system. A clear posterior capsule was observed after the surgery in patients undergoing this method. This method of rotating IOLs is a simple, effective, and safe way to prevent PCO by clearing residual LECs and can be carried out without extra tools or skills.

A clear capsular bag was formed after the I/A step (Figure 1A). However, some cortical fragments were observed in the capsular bag after rotating and polishing the IOL (Figure 1B).
This process can also be performed using a hook. Similarly, the posterior capsule was clear after capsular polishing by the I/A tip (Figure 2A). Through fast rotation and movement of the IOL, some residuals appeared in the caps...

Watch this Scientific Journal Video about Enhancing Visual Outcomes in Cataract Surgery: A Novel Technique to Prevent Posterior Capsular Opacification Through IOL Rotation at JoVE.com

Author Spotlight: Enhancing Visual Outcomes in Cataract Surgery: A Novel Technique to Prevent Posterior Capsular Opacification Through IOL Rotation 

The present protocol describes removing residual epithelial cells by rotating the intraocular lens in extracapsular cataract surgery without extra tools for preventing posterior capsular opacification.

Rotating the Intraocular Lens to Prevent Posterior Capsular Opacification in Cataract Surgeries

Posterior capsule opacification (PCO) is a common postoperative complication of extracapsular cataract surgery, which is caused by the proliferation and ...

rotating-intraocular-lens-to-prevent-posterior-capsular-opacification

Research

JoVE Journal

Medicine

2.1K Views.  Peking University Third Hospital. The present protocol describes removing residual epithelial cells by rotating the intraocular lens in extracapsular cataract surgery without extra tools for preventing posterior capsular opacification.

Video: Author Spotlight: Enhancing Visual Outcomes in Cataract Surgery: A Novel Technique to Prevent Posterior Capsular Opacification Through IOL Rotation 

The Measurement and Treatment of Suppression in Amblyopia

Amblyopia, a developmental disorder of the visual cortex, is one of the leading causes of visual dysfunction in the working age population. Current estimates put the prevalence of amblyopia at approximately 1-3%1-3, the majority of cases being monocular2. Amblyopia is most frequently caused by ocular misalignment (strabismus), blur induced by unequal refractive error (anisometropia), and in some cases by form deprivation.
Although amblyopia is initially caused by abnormal visual input in infancy, once established, the visual deficit often remains when normal visual input has been restored using surgery and/or refractive correction. This is because amblyopia is the result of abnormal visual cortex development rather than a problem with the amblyopic eye itself4,5 . Amblyopia is characterized by both monocular and binocular deficits6,7 which include impaired visual acuity and poor or absent stereopsis respectively. The visual dysfunction in amblyopia is often associated with a strong suppression of the inputs from the amblyopic eye under binocular viewing conditions8. Recent work has indicated that suppression may play a central role in both the monocular and binocular deficits associated with amblyopia9,10 .
Current clinical tests for suppression tend to verify the presence or absence of suppression rather than giving a quantitative measurement of the degree of suppression. Here we describe a technique for measuring amblyopic suppression with a compact, portable device11,12 . The device consists of a laptop computer connected to a pair of virtual reality goggles. The novelty of the technique lies in the way we present visual stimuli to measure suppression. Stimuli are shown to the amblyopic eye at high contrast while the contrast of the stimuli shown to the non-amblyopic eye are varied. Patients perform a simple signal/noise task that allows for a precise measurement of the strength of excitatory binocular interactions. The contrast offset at which neither eye has a performance advantage is a measure of the "balance point" and is a direct measure of suppression. This technique has been validated psychophysically both in control13,14 and patient6,9,11 populations.
In addition to measuring suppression this technique also forms the basis of a novel form of treatment to decrease suppression over time and improve binocular and often monocular function in adult patients with amblyopia12,15,16 . This new treatment approach can be deployed either on the goggle system described above or on a specially modified iPod touch device15.

Amblyopia is a developmental disorder of the visual cortex that is often accompanied by strong suppression of one eye. We present a new technique for measuring and treating interocular suppression in patients with amblyopia that can be deployed using virtual reality goggles or a portable iPod Touch device.

Amblyopia, a developmental disorder of the visual cortex, is one of the leading causes of visual dysfunction in the working age population. Current ...

Characterization of Molecular Mechanisms of In vivo UVR Induced Cataract

Cataract is the leading cause of blindness in the world 1. The World Health Organization defines cataract as a clouding of the lens of the eye which impedes the transfer of light. Cataract is a multi-factorial disease associated with diabetes, smoking, ultraviolet radiation (UVR), alcohol, ionizing radiation, steroids and hypertension. There is strong experimental 2-4 and epidemiological evidence 5,6 that UVR causes cataract. We developed an animal model for UVR B induced cataract in both anesthetized 7 and non-anesthetized animals 8.
The only cure for cataract is surgery but this treatment is not accessible to all. It has been estimated that a delay of onset of cataract for 10 years could reduce the need for cataract surgery by 50% 9. To delay the incidence of cataract, it is needed to understand the mechanisms of cataract formation and find effective prevention strategies. Among the mechanisms for cataract development, apoptosis plays a crucial role in initiation of cataract in humans and animals 10. Our focus has recently been apoptosis in the lens as the mechanism for cataract development 8,11,12. It is anticipated that a better understanding of the effect of UVR on the apoptosis pathway will provide possibilities for discovery of new pharmaceuticals to prevent cataract.
In this article, we describe how cataract can be experimentally induced by in vivo exposure to UVR-B. Further RT-PCR and immunohistochemistry are presented as tools to study molecular mechanisms of UVR-B induced cataract.

Characterization of Molecular Mechanisms of In vivo UVR Induced Cataract

Cataract is the leading cause of blindness in the world. Solar ultraviolet radiation (UVR) is the main risk factor for cataract development. An animal model of far UVR-B induced cataract was developed. In this article we describe methods for investigation of cataract formation: exposure to UVR, quantitative RT-PCR and immunohistochemistry.

Cataract is the leading cause of blindness in the world 1. The World Health Organization defines cataract as a clouding of the lens of the eye which ...

Rat Model of Photochemically-Induced Posterior Ischemic Optic Neuropathy

Posterior Ischemic optic neuropathy (PION) is a sight-devastating disease in clinical practice. However, its pathogenesis and natural history have&#160;remained poorly understood. Recently, we developed a reliable, reproducible animal model of PION and tested the treatment effect of some neurotrophic factors in this model1. The purpose of this video is to demonstrate our photochemically induced model of posterior ischemic optic neuropathy, and to evaluate its effects with retrograde labeling of retinal ganglion cells. Following surgical exposure of the posterior optic nerve, a photosensitizing dye, erythrosin B, is intravenously injected and a laser beam is focused onto the optic nerve surface. Photochemical interaction of erythrosin B and the laser during irradiation damages the vascular endothelium, prompting microvascular occlusion mediated by platelet thrombosis and edematous compression. The resulting ischemic injury yields a gradual but pronounced retinal ganglion cell dieback, owing to a loss of axonal input - a remote, injury-induced and clinically relevant outcome. Thus, this model provides a novel platform to study the pathophysiologic course of PION,&#160;and can be further optimized for testing therapeutic approaches for optic neuropathies as well as other CNS ischemic diseases.

The goal of this protocol is to photochemically induce ischemic injury to the posterior optic nerve in rat. This model is critical to studies of the pathophysiology of posterior ischemic optic neuropathy, and therapeutic approaches for this and other optic neuropathies, as well as of other CNS ischemic diseases.

Posterior Ischemic optic neuropathy (PION) is a sight-devastating disease in clinical practice. However, its pathogenesis and natural history ...

Circumscribed Capsular Infarct Modeling Using a Photothrombotic Technique

Recent increase in the prevalence rate of white matter stroke demands specific research in the field. However, the lack of a pertinent animal model for white matter stroke has hampered research investigations. Here, we describe a novel method for creating a circumscribed capsular infarct that minimizes damage to neighboring gray matter structures. We used pre-surgery neural tracing with adeno-associated virus-green fluorescent protein (AAV-GFP) to identify somatotopic organization of the forelimb area within the internal capsule. The adjustment of light intensity based on different optical properties of gray and white matter contributes to selective destruction of white matter with relative preservation of gray matter. Accurate positioning of optical-neural interface enables destruction of entire forelimb area in the internal capsule, which leads to a marked and persistent motor deficit. Thus, this technique produces highly replicable capsular infarct lesions with a persistent motor deficit. The model will be helpful not only to study white matter stroke (WMS) at the behavioral, circuit, and cellular levels, but also to assess its usefulness for development of new therapeutic and rehabilitative interventions.

This manuscript describes a modeling technique of capsular infarct. Here we utilized a modified photothrombotic technique with low intensity of light after pre-surgery target mapping. Using this technique, we created a circumscribed capsular infarct model with persistent motor impairment.

Recent increase in the prevalence rate of white matter stroke demands specific research in the field. However, the lack of a pertinent animal model for ...

Use of Rabbit Eyes in Pharmacokinetic Studies of Intraocular Drugs

The intraocular route of drug administration enables the delivery of high concentrations of therapeutic drugs, while minimizing their systemic absorption. Several drugs are administered into the anterior chamber or vitreous, and the intraocular injection has been effective in curing various intraocular diseases. Rabbit eyes have been widely used for ophthalmic research, as the animal is easy to handle and economical compared to other mammals, and the size of a rabbit eye is similar to that of a human eye. Using a 30 G needle, drugs can be injected into the intracameral and intravitreal spaces of rabbit eyes. The eyeballs are then frozen until analysis, and can be divided into the aqueous humor, vitreous, and retina/choroid. The vitreous and retina/choroid samples can be homogenized and solubilized before analysis. Then, immunoassays can be performed to measure the concentrations of intraocular drugs in each compartment. Appropriate pharmacokinetic models can be used to calculate several parameters, such as the half-life and maximum concentration of the drug. Rabbit eyes can be a good model for pharmacokinetic studies of intraocular drugs.

Rabbits are widely used to study the pharmacokinetics of intraocular drugs. We describe a method for conducting pharmacokinetic studies of intraocular drugs using rabbit eyes.

The intraocular route of drug administration enables the delivery of high concentrations of therapeutic drugs, while minimizing their systemic absorption. ...

Impression Cytology of the Lid Wiper Area

Few reports on the cellular anatomy of the lid wiper (LW) area of the inner eyelid exist and only one report makes use of cytological methods. The optimization of a method of collecting, staining and imaging cells from the LW region using impression cytology (IC) is described in this study. Cells are collected from the inner surface of the upper eyelid of human subjects using hydrophilic polytetrafluoroethylene (PTFE) membranes, and stained with cytological dyes to reveal the presence of goblet cells, mucins, cell nuclei and various degrees of pre- and para-keratinization. Immunocytochemical dyes show cell esterase activity and compromised cell membranes by the use of a confocal scanning laser microscope. Up to 100 microscopic digital images are captured for each sample and stitched into a high-resolution, large scale image of the entire IC span. We demonstrate a higher sensitivity of IC than reported before, appropriate for identifying cellular morphologies and metabolic activity in the LW area. To our knowledge, this is the first time this selection of fluorescent dyes was used to image LW IC membranes. This protocol will be effective in future studies to reveal undocumented details of the LW area, such as assessing cellular particularities of contact lens wearers or patients with dry eye or lid wiper epitheliopathy.

We collected, stained and imaged cells from the conjunctiva of the inner eyelid margin of human subjects. By characterizing cell morphology and metabolic activity, this method may further our understanding of dry eye and the role that friction between the ocular surfaces may play in perceiving ocular discomfort.

Few reports on the cellular anatomy of the lid wiper (LW) area of the inner eyelid exist and only one report makes use of cytological methods. The ...

ADSC-sheet Transplantation to Prevent Stricture after Extended Esophageal Endoscopic Submucosal Dissection

In past years, the cell-sheet construct has spurred wide interest in regenerative medicine, especially for reconstructive surgery procedures. The development of diversified technologies combining adipose tissue-derived stromal cells (ADSCs) with various biomaterials has led to the construction of numerous types of tissue-engineered substitutes, such as bone, cartilage, and adipose tissues from rodent, porcine, or human ADSCs. Extended esophageal endoscopic submucosal dissection (ESD) is responsible for esophageal stricture formation. Stricture prevention remains challenging, with no efficient treatments available. Previous studies reported the effectiveness of mucosal cell-sheet transplantation in a canine model and in humans. ADSCs are attributed anti-inflammatory properties, local immune modulating effects, neovascularization induction, and differentiation abilities into mesenchymal and non-mesenchymal lineages. This original study describes the endoscopic transplantation of an ADSC tissue-engineered construct to prevent esophageal stricture in a swine model. The ADSC construct was composed of two allogenic ADSC sheets layered upon each other on a paper support membrane. The ADSCs were labeled with the PKH67 fluorophore to allow probe-based confocal laser endomicroscopy (pCLE) monitoring. On the day of transplantation, a 5-cm and hemi-circumferential ESD known to induce esophageal stricture was performed. Animals were immediately endoscopically transplanted with 4 ADSC constructs. The complete adhesion of the ADSC constructs was obtained after 10 min of gentle application. Animals were sacrificed on day 28. All animals were successfully transplanted. Transplantation was confirmed on day 3 with a positive pCLE evaluation. Compared to transplanted animals, control animals developed severe strictures, with major fibrotic tissue development, more frequent alimentary trouble, and reduced weight gain. In our model, the transplantation of allogenic ADSCs, organized in double cell sheets, after extended ESD was successful and strongly associated with a lower esophageal stricture rate.

This study reports a successful method of endoscopical adipose tissue-derived stromal cell (ADSC)-sheet transplantation for esophageal stricture prevention after an extended endoscopic submucosal dissection (ESD) in a swine model.

In past years, the cell-sheet construct has spurred wide interest in regenerative medicine, especially for reconstructive surgery procedures. The ...

Ultrahigh Resolution Mouse Optical Coherence Tomography to Aid Intraocular Injection in Retinal Gene Therapy Research

HR-SD-OCT is utilized to monitor the progression of photoreceptor degeneration in live mouse models, assess the delivery of therapeutic agents into the subretinal space, and to evaluate toxicity and efficacy in vivo. HR-SD-OCT uses near infrared light (800-880 nm) and has optics specifically designed for the unique optics of the mouse eye with sub-2-micron axial resolution. Transgenic mouse models of outer retinal (photoreceptor) degeneration and controls were imaged to assess the disease progression. Pulled glass microneedles were used to deliver sub retinal injections of adeno-associated virus (AAV) or nanoparticles (NP) via a trans-scleral and trans-choroidal approach. Careful positioning of the needle into the subretinal space was required prior to a calibrated pressure injection, which delivers fluid into the sub retinal space. Real time subretinal surgery was conducted on our retinal imaging system (RIS). HR-SD-OCT demonstrated progressive uniform retinal degeneration due to expression of a toxic mutant human mutant rhodopsin (P347S) (RHOP347S) transgene in mice. HR-SD-OCT allows rigorous quantification of all the retinal layers. Outer nuclear layer (ONL) thickness and photoreceptor outer segment length (OSL) measurements correlate with photoreceptor vitality, degeneration, or rescue. The RIS delivery system allows real-time visualization of subretinal injections in neonatal (~P10-14) or adult mice, and HR-SD-OCT immediately determines success of delivery and maps areal extent. HR-SD-OCT is a powerful tool that can evaluate the success of subretinal surgery in mice, in addition to measuring vitality of photoreceptors in vivo. HR-SD-OCT can also be used to identify uniform animal cohorts to evaluate the extent of retinal degeneration, toxicity, and therapeutic rescue in preclinical gene therapy research studies.

Here we demonstrate a novel approach to using high resolution spectral-domain optical coherence tomography (HR-SD-OCT) to assist delivery of gene therapy agents into the subretinal space, assess its areal coverage, and characterize photoreceptor vitality.

HR-SD-OCT is utilized to monitor the progression of photoreceptor degeneration in live mouse models, assess the delivery of therapeutic agents into the ...

Posterior Approach for Debridement of the Psoas Abscess

This method focuses on outlining a safe zone for irrigation and debridement of a psoas abscess through a posterior approach. Initially, an anterior approach to the spine was performed to ensure that the anterior longitudinal ligament and the psoas muscle could be visualized. All the abdominal organs were removed. Subsequently, a posterior approach was performed to remove the paraspinal muscles from L1&#8211;L5. The transverse processes, pars interarticularis and lamina of L1&#8211;L5 were identified. The exiting nerve root was identified between the transverse processes and followed into the substance of the psoas muscle. Using the anterior and posterior approach, the lumbar plexus was isolated from the substance of the psoas muscle. Before and after various steps of dissection, digital photographs were obtained. These images were uploaded into ImageJ and multiple measurements, including the distance between the lateral superior and inferior tip of each TP to the most lateral region of the plexus, the distance between the lateral superior and inferior tip of the TP to the lateral edge of the psoas, and the width of the lumbar plexus were recorded. The safe zone for entering the substance of the psoas muscle was defined between the lateral edge of the psoas muscle and the lateral edge of the lumbar plexus. The relationship of this interval to the tip of the transverse process at each level was measured and reported.

This is a cadaveric study investigating the landmarks for the posterior approach for irrigation and debridement of the psoas abscess. The interval between the transverse processes (TP) was used to access the substance of the psoas muscle.

This method focuses on outlining a safe zone for irrigation and debridement of a psoas abscess through a posterior approach. Initially, an anterior ...

Modified Posterior Vertebral Column Resection for Patients with Thoracolumbar Kyphotic Deformity

Old compression vertebrae fracture or congenital kyphoscoliosis with abnormal vertebral body development and other diseases that invade the spine may cause severe thoracolumbar kyphotic deformity, often accompanied by intractable low back pain or compression of the spinal cord, leading to severe neurological symptoms or even paralysis. If conservative treatment cannot relieve the symptoms or correct the deformities, surgical treatment is usually needed. For severe kyphotic deformity, reconstruction of the physiological curvature and rigid fixation determine the prognosis of the patients. Osteotomy and orthopedics are the standard procedure for deformities with severe compression of the front and middle column, but the trauma to the patients is high, with a long operation time and massive blood loss. To avoid these disadvantages, we have developed a modified technique to remove the diseased vertebra unilaterally. In this technique, we use a modified trephine to resect the vertebral columns like in the pedicle screw technique by adding a locking instrument that can restrict the trephine to lower the risk of osteotomy and shorten the surgery time and blood loss.

We describe a modified technique for resecting the posterior vertebral column unilaterally based on a modified trephine for patients with thoracolumbar kyphotic deformity.

Old compression vertebrae fracture or congenital kyphoscoliosis with abnormal vertebral body development and other diseases that invade the spine may ...