Analysis of Retinal Nerve Fibre Layer Changes in Cases of Phacomorphic Angle Closure Post Phacoemulsification

Abstract

Introduction: To investigate the retinal nerve fibre layer (RNFL) changes after an acute attack of phacomorphic angle closure. Methods: This prospective study involved 25 cases of phacomorphic angle closure that underwent phacoemulsification and intraocular lens insertion after intraocular pressure lowering. Apart from visual acuity and intraocular pressure (IOP), RNFL thickness was measured by optical coherence tomography (OCT) at 3–6 months post attack. Result: All cases had mean phacomorphic duration of <10 days. Postoperatively, best correct Snellen visual acuity was 0.42±0.23 and IOP at 6 months was 13.92 ± 2.41 mmHg. There was no difference RNFL between the attack and contralateral eye at 3 months post attack (both p = 0.102). At 6 months post attack, there was significant thinning in the average (p <0.001), superior (p =<0.001), and inferior (p = 0.001) RNFL. Patients with <5 days duration of phacomorphic angle closure are likely to have reasonable postoperative vision. Conclusion: An acute episode of phacomorphic angle closure can trigger an accelerated RNFL thinning despite normal IOP and open angles, most noticeable in the superior and inferior quadrants, occurring between 3 and 6 months post attack. There is a need of long term follow up of such patients.