Visual Outcome And Intraocular Pressure Changes After Nd: Yag Laser Capsulotomy In Patients With Posterior Capsular Opacification: A One Year Hospital Based Prospective Study

Abstract

Posterior capsular opacification (PCO) is the most frequent post operative complication of cataract surgery. Advances in surgical techniques, intraocular lens (IOL) materials and designs have reduced the incidence of PCO development rate; however, it remains a significant problem resulting in suboptimal visual outcome of cataract surgery. Nd: YAG (Neodymium-Yttrium-Aluminum-Garnet) laser is non-invasive and effective means to deal with PCO. However safe it may have some complications. Rise of intraocular pressure is frequently experienced and incompletely understood complication of YAG laser capsulotomy and documented with contradictory results. AIMS & OBJECTIVES Primary objective To assess the visual outcome after Nd: YAG laser capsulotomy Secondary objectives To evaluate IOP changes after Nd: YAG laser capsulotomy and to observe any other complications after Nd: YAG laser capsulotomy. MATERIALS AND METHOD This prospective study evaluated 60 eyes of 60 patients undergoing Nd:YAG capsulotomy for posterior capsular opacity. Complete ocular examination including Best Corrected Visual Acuity with Snellen’s chart, slit lamp examination, fundus examination and applanation tonometry were performed pre and post laser in all cases. Posterior capsulotomy was done with APPA YAG laser machine. All cases were examined pre and post laser after 1 hour, 1 week and 1 month. The quantitative variables were expressed as mean ± standard deviation (SD) and compared between the various follow-ups using paired t-test. The qualitative variables were expressed in terms of frequencies and percentages and compared using Chi-square/Fisher's exact test. A p-value < 0.05 was considered statistically significant. Statistical Package for Social Sciences (SPSS) version 16.0 was used for the statistical analysis. RESULTS In our study, there were 26 (43.33 %) males and 34 (56.67 %) females. Maximum number of patients were in the age group between 61 to 70 years i.e. 43.33 % followed by patients in the age group 71-80 years i.e. 25%.Average age of the patient was 63.98 years. Pre laser visual acuity ranged from 1/60 to 6/12. Results showed statistically significant improvement in Best Corrected Visual Acuity with 28.33 % patients had BCVA 6/6, 43.33 % had Best Corrected Visual Acuity 6/9 and 23.3 % had BCVA 6/12 at 1 month of post Nd:YAG laser posterior capsulotomy. Baseline mean IOP was mean 15.07 ± 2.81 mm Hg and post laser mean IOP was 17.20 ± 3.46 mm Hg at 1 hour, 16.70 ± 4.45 mm Hg at 1 day which returned to 15.38 ± 3.79 mm Hg on 1 week and returned to baseline value 15.03 ±2.99 mm Hg at 1 month. P values show statistically significant increase in IOP at 1 week. It was observed that 17 % of the patients showed no change in IOP while 63 % patients showed elevated IOP. Among these 78 % patients show rise in IOP that was ≤ 5mm Hg while only 5 % of the patients had a rise of IOP more than 5 mm Hg. Most of these patients achieved their baseline IOP within 1 week and only 5 % patients had rise in IOP compared to baseline IOP on 1 week. Only 1 patient showed elevated IOP after 1 month that was only of 1 mm Hg. DISCUSSION Our study showed that Nd:YAG laser posterior capsulotomy provides excellent outcome in terms of improvement in Best Corrected Visual Acuity (BCVA). Results were statistically significant and most of the patients achieved vision upto or more than 6/9 as per snellen’s chart. Most of the patients had a rise of IOP < 5 mm Hg which was transient and routine anti glaucoma medication may not be needed in all patients undergoing Nd: YAG capsulotomy. When correctly done with proper patient selection and thorough fundus examination, it is very economical, convenient, fast and non-invasive OPD procedure with immediate results. It carries a low but limited risk of complications. These complications are rare and rarely vision threatening. CONCLUSION Nd:YAG laser capsulotomy is effective, relatively safe, non-invasive, fast, outpatient procedure to improve hindered vision by PCO. To avoid complication it is suggested to screen the patient properly before the procedure and exercise caution and vigilance in high risk patients.