Two Different Cataract Surgical Procedures to Prevent Posterior Capsule Opacification

Effectiveness of Two Different Surgical Procedures to Prevent Posterior Capsule Opacification in Age-related Cataract Patients

In this study, the investigators introduce a new "capsule-reserved" cataract surgical procedure in which anterior lens capsule is reserved and attached onto posterior lens capsule in the purpose of preventing posterior capsule opacification (PCO). A prospective randomized controlled study is reported to compare the new "capsule-reserved" surgical procedure with conventional one on the effectiveness to prevent posterior capsule opacification in age-related cataract patients.

A prospective, randomized controlled study of 240 eligible patients will been enrolled. Two eyes of each patient were assigned randomly to two groups respectively: Group I; anterior lens capsule is conventionally not reserved after continuous curvilinear capsulorhexis, while in Group II, anterior lens capsule is innovatively reserved and attached onto posterior lens capsule. This novel adjusted surgical procedure, featured by using the reserved anterior lens capsule to protect the peri-capsule microenvironment and prevent PCO, is conceptual different from the traditional cataract surgical procedure. Clinical examinations including posterior capsule opacification grading score, central posterior capsule thickness, central posterior capsule density, best corrected visual acuity, contrast sensitivity were carried out preoperatively and at each postoperative visit.

In this group, the anterior lens capsule was reserved after continuous curvilinear capsulorhexis. The reserved anterior capsule was pressed flattened by the optical surface of the IOL and attached onto the posterior lens capsule. Phacoemulsification was performed with the same device and handpieces, using the same phaco chop technique as in the conventional procedure group.

In this group, the anterior lens capsule was not reserved or attached onto the posterior lens capsule.

The anterior lens capsule was reserved after continuous curvilinear capsulorhexis. The reserved anterior capsule was pressed flattened by the optical surface of the IOL and attached onto the posterior lens capsule.

Posterior capsule opacification（PCO）was recorded by standardized slit lamp retroillumination images and analyzed using the EPCO2000 program. The severity of PCO was clinically graded from 0 (none) to 4 (severe)

post-operative day 1, post-operative week 1, post-operative month 1, post-operative month 3, post-operative month 6, post-operative year 1

post-operative day 1, post-operative week 1, post-operative month 1, post-operative month 3, post-operative month 6, post-operative year 1

Best-corrected visual acuity (BCVA) was measured, using an ETDRS chart and auto-refraction as refined by an ophthalmologist.

post-operative day 1, post-operative week 1, post-operative month 1, post-operative month 3, post-operative month 6, post-operative year 1

post-operative day 1, post-operative week 1, post-operative month 1, post-operative month 3, post-operative month 6, post-operative year 1

Inclusion Criteria: Aged 50 years or above Both eyes were diagnosed with age-related cataract Both eyes were planed to undergo the "Phacoemulsification and IOL implantation" surgery with 1 month Biocular BCVA improvement post surgery was feasible judged by the ophthalmologists. Exclusion Criteria: Other ocular diseases ACD<3CT Combined cataract surgery (trabeculoplasty, keratoplasty) Lens pseudoexfoliation syndrome combined with glaucoma or zonular abnormalities Previous intraocular surgery or trauma (laser not included) Uveitis Recent ocular infection Proliferative diabetic retinopathy Diabetes mellitus Congenital ocular abnormalities (aniridia, congenital cataract) Atrophy of iris Participants with previous clinical trials 30 days before surgery Using prostanoid eye drops Uncontrolled systematic diseases

Luo L, Lin H, Chen W, Qu B, Zhang X, Lin Z, Chen J, Liu Y. Intraocular lens-shell technique: adjustment of the surgical procedure leads to greater safety when treating dense nuclear cataracts. PLoS One. 2014 Nov 17;9(11):e112663. doi: 10.1371/journal.pone.0112663. eCollection 2014.

Lin H, Yan P, Yu K, Luo L, Chen J, Lin Z, Chen W. Anterior segment variations after posterior chamber phakic intraocular lens implantation in myopic eyes. J Cataract Refract Surg. 2013 May;39(5):730-8. doi: 10.1016/j.jcrs.2012.12.026. Epub 2013 Mar 14.

Lin HT, Chen WR, Ding ZF, Chen W, Wu CR. Clinical evaluation of two multifocal intraocular lens implantation patterns. Int J Ophthalmol. 2012;5(1):76-83. doi: 10.3980/j.issn.2222-3959.2012.01.16. Epub 2012 Feb 18.

Luo L, Lin H, He M, Congdon N, Yang Y, Liu Y. Clinical evaluation of three incision size-dependent phacoemulsification systems. Am J Ophthalmol. 2012 May;153(5):831-839.e2. doi: 10.1016/j.ajo.2011.10.034. Epub 2012 Feb 4.