Effect of Nd: YAG laser capsulotomy on macular thickness and intraocular pressure for the treatment of posterior capsular opacification

Poster Details

First Author: Tahir KansuBozkurt TURKEY

Co Author(s):    Gülünay Kiray   Betül İlkay Sezgin Akçay   Esra Güney        

Abstract Details

Purpose:

To evaluate the effect of the energy level delivered by Nd:YAG Laser on macular thickness and intraocular pressure following capsulotomy for the treatment of posterior capsule opacification

Setting:

: Retrospective case series

Methods:

Twenty-two eyes of 22 patients with posterior capsule opacification of different grades were included in the study. All patients underwent a comprehensive ophthalmic examination including best corrected visual acuity (BCVA), Optical Coherens Tomography (OCT) (to evaluate macular thickness) and measurement of intraocular pressure (IOP) by Goldmann applanation tonometry at each visit. Findings were recorded before Nd:YAG laser capsulotomy and at postoperative 1st week and 1st month. Postoperatively each patient were on the regimen of florometholone (S:4x1) and brimonidine (S:2x1) for 1 week. Main outcome measures were the correlation of total used energy during capsulotomy and changes of central macular thickness (CMT) and intraocular pressure levels. Additionally, patients were divided into two groups according to media total energy delivered: Group1 (≤94 mJ)(n=11) and Group2 (>94 mJ)(n=11). Secondary outcome measures were evaluation of CMT and IOP changes between these two groups.

Results:

Mean total energy level was 103 ± 56 mJ(median=94 mJ). Mean BCVA was significantly better than preoperative levels(T test, p<0.01).Mean CMT of patients were 214±17(preoperative), 231±12(at postoperative 1st week) and 229± 9(at postoperative 1st month).Mean BCVA was not found to be correlated with mean CMT levels at any visit.There was no significant correlation between the energy delivered and change of CMT at each interval(Pearson Test, p>0.05).However, CMT measured at both 1st week and 1st month were significantly greater than preoperative levels(T test, p<0.01).Mean IOP were 14.7±2.8(preoperative) 15.5±3.5(at postoperative 1st week and 17.4±3.2(at postoperative 1st month).Mean total energy levels were not significantly correlated to any of the following IOP measurements(IOP at 1st week and 1st month, mean change of IOP at 1st week and 1st month)(Pearson, p>0.05).In Group 1 and Group 2, mean total energy delivered were 59±19 mJ and 148±44 mJ, respectively.Analysis of Group 1 and Group 2 revealed out that there was no significant difference between two groups in terms of change of CMT at 1st week and 1st month(p>0.05).On the other hand, mean IOP change in Group 2 at 1st week and 1st month were significantly higher than Group 1(Mann Whitney Test, p=0.01 and p=0.03, respectively)

Conclusions:

This study showed that both macular thickness and IOP had a tendency to increase following Nd: YAG laser capsulotomy, but there was no correlation found associated with energy delivered. Many authors showed similar results in terms of macular thickness. However, it may be hypothesized that these results were due to optical properties of OCT device since present study also showed that CMT or change of CMT did not differ any change of BSCVA associated significantly. Higher energy levels (≥94 mJ) caused higher IOP changes in the following period even with the prophylactic use of antiglaucomatous agents in the 1st following week. Thus, in spite of the fact that none of the patients in these case series experienced high IOP levels (in need of IOP lowering) at 1st month, we think that meticulous care to use lower levels of energy may be advantageous to lower the risks of high IOP in the postoperative period. FINANCIAL INTEREST: NONE