Posters

Incidence of posterior capsule opacification in square edge PCIOLs

Poster Details

First Author: M.Menta Ravindra INDIA

Co Author(s):    V. Kesaraju   J. Karnati           

Abstract Details

Purpose:

To study the incidence of posterior capsule opacification (PCO) in patients implanted with 360 degree square edge polymethyl methacrylate (PMMA) posterior chamber intraocular lens (PCIOL)after cataract surgery.

Setting:

Mamata Medical College & General and Super Speciality Hospital, Khammam, India between October 2011 and September 2013.

Methods:

This prospective study includes 50 eyes of 50 patients diagnosed as uncomplicated senile age related cataract. Follow-up period was confined to one year following the date of surgery. Post operative evaluation: The PCO was assessed by the following grading system. No. PCO - No evidence of PCO seen before and after pupil dialatation to a minimum of 6mm. With a direct ophthalmoscopy a clear view of optic disc, vessels, and nerve fiber layer was obtained. Grade I - PCO seen only with pupil dilated to a minimum of 6mm. With a direct Ophthalmoscopy, a clear view of optic disc, vessels and nerve fiber layerwas obtained. Grade II - PCO in central axis, detectable with an undilated pupil. With a direct Ophthalmoscopy, mild obscuration of fundus details. Optic disc seen but not nerve fiber layer. Grade III-PCO in the central visual axis with an undilated pupil. On direct Ophthalmoscopy, there is marked obscuration of fundus details, even margins of optic disc is not seen clearly.

Results:

All patients were followed up completely for the mean period of 8 months. Of the 50 patients, three patients developed clinically significant Posterior capsule opacification in the central visual axis obscuring the fundus details (6%). In two cases (4%) it is of elschnig's pearls type and in one patient(2%) it is thick fibrous membrane type of PCO . Nd:YAG laser capsulotomy was performed 8 months after surgery. The BCVA of these patients improved from 6/9 to 6/6 after capsulotomy procedure. The follow up of the patients was 8 months to one year. All 50 patients completed 8 months of follow-up on average. PCO of fibrosis type developed earlier (6 months follow up), when compared with elschnig's pearl type (8 months follow up). The incidence of PCO is very much reduced in patients with square edge PMMA IOL implantation (6%), when compared with round edge PMMA IOL (15%) during the 2 year period. Visual outcome in 43 patients was 6/6 (86.8%) and 6/9 in 7 (14%) patients. Among the seven patients with PCO, three patients improved to 6/6 after Nd:YAG laser capsulotomy procedure. Final visual outcome of 6/6 was achieved in 46 patients (92%) and 6/9 in 4 patients (8%).

Conclusions:

The IOL design plays an important role in the prevention of posterior capsule opacification in elderly patients. 5 cases were followed up for 1 yr and 7 cases were followed up for 10 months, which did not develop the PCO. That confirms the barrier effect of square edged IOL for longer periods also. Longer follow up was very much necessary to substantiate this incidence. Decentration of IOL was associated with PCO in one patient in this study. So the barrier effect of the IOL optic, the efficacy of which is dependent on good, in-the-bag fixation of the IOL seems to be of critical importance as a necessary second line of defense in retarding the proliferation & migration of Lens Epithelial Cells. Thus it is proved that the PMMA IOL with a 3600 square edge optic is helpful in reducing but not eradicating the rates of PCO which proves more economical for Indian patients. FINANCIAL INTEREST: NONE