Change in Retinal Nerve Fiber Layer Thickness after Phacoemulsification and its Correlation with Phaco Power and Phaco Duration

Abstract

Purpose: To determine the change in RNFL thickness after phacoemulsification using OCT and to determine the correlation of RNFL change with phaco duration and phaco power.

Subjects and Methods: After getting IRB approval and taking informed consent, a quasi-experimental study was carried out at Eye department of Gujranwala Medical College. Fifty patients of either gender b/w 50-70 years of age with grade II senile cataract were enrolled in this study. Pre-operatively RNFL thickness was determined using OCT and post-operatively after phacoemulsification, the same procedure was repeated at 1 month and 3 months period. Change in RNFL thickness was determined and paired sample t-test was used to compare mean values pre and post-operatively. Correlation of this change with phaco power and phaco duration was determined using pearson’s correlation test.

Results: Out of 50, 54% were male while 46% were female. Mean age recorded was 60.5±5.42 years. Mean phaco power recorded was 44.4±5.47% while mean phaco duration noted was 9.4±3.51 seconds. Mean pre-operative RNFL thickness was 90.64±4.6µm that increased to 95.62±5.92µm at 1-month post-op. and then declined to 89.66±4.86µm at 3 months post-op. with significant p-value of 0.00 (p-value< 0.05). Pearson’s correlation test showed strong positive association of +0.77 b/w phaco power and change in RNFL thickness while weak positive association of +0.031 was determined b/w phaco duration and change in RNFL thickness.

Conclusion: In conclusion, phacoemulsification causes significant change in RNFL thickness post-operatively and this change has strong positive association with phaco power used and very weak positive association with phaco duration.