In vivo confocal microscopy (IVCM) analysis of corneal sub-basal nerve plexus (SNP) and corneal sensitivity after micropulse transscleral cyclophotocoagulation (MP-TSCPC) in glaucoma patients

PurposeTo investigate the clinical outcome of micropulse transscleral cyclophotocoagulation (MP-TSCPC) and its effect on corneal sensitivity, as well as corneal nerve parameters using in vivo confocal microscope (IVCM) in eyes with glaucoma.Patients and methodsThis was a prospective longitudinal study recruiting consecutive glaucoma patients who were scheduled to undergo MP-TSCPC for intraocular pressure (IOP) control in a tertiary center. Pre-operative and postoperative clinical parameters were compared including best-corrected visual acuity, IOP, number of topical glaucoma medication, requirement of oral acetazolamide and corneal sensitivity. Intraoperative and postoperative complications were recorded. Pre-operative and postoperative corneal nerve parameters measured using IVCM were analysed in both operated and non-operated eye. All clinical and imaging parameters were compared longitudinally between baseline, postoperative 2 weeks and 1 month.ResultsTwenty consecutive glaucoma patients who received MP-TSCPC between January 2024 and May 2024 were recruited. Postoperatively, there was a significant reduction in IOP (p = 0.000) and oral acetazolamide use (p = 0.001) while visual acuity were maintained (p = 0.710). However, there were reduced corneal sensitivity (p = 0.014), decrease in corneal nerve fibre density (CNFD) (p = 0.017) and corneal nerve branch density (CNBD) (p = 0.047) as detected by IVCM from baseline to 1 month in the operated eye.ConclusionMP-TSCPC is an effective glaucoma treatment in terms of IOP control and reduction of glaucoma medications. However, it may potentially result in reduced corneal sensitivity, corneal nerve fiber density and branch density at postoperative 1 month.