A clinical study of immediate postoperative corneal edema in patients undergoing minor incision cataract surgery in a teaching hospital.

Abstract

Background: Transient corneal edema is one of the most common complications observed after cataract surgery. If the center of the cornea is involved, it may result in impaired visual acuity in the immediate postoperative period. Hence, it concerns both the surgeon and the patient. Descemet's membrane detachment (DMD) is a less recognized cause of immediate corneal edema that can lead to long-term endothelial failure. Immediate recognition and surgical management may preserve vision in these patients.

Objectives: To determine the proportion of corneal edema in subjects undergoing manual minor incision cataract surgery, grade them under slit-lamp examination and anterior segment optical coherence tomography, and correlate the findings.

Materials and methods: We included patients who underwent manual small-incision cataract surgery (SICS) in the Department of Ophthalmology of a teaching hospital from November 2019 to May 2021. Postoperatively, all patients were subjected to detailed ophthalmic evaluation, and those with corneal edema underwent anterior segment OCT to determine the corneal edema and status of Descemet's membrane.

Results: Out of 922 patients who underwent manual SICS, 91 patients (9%) had corneal edema; the mean corneal thickness in the area of corneal edema on AS-OCT was found to be 726.92µm with an SD of 137.00µm and the mean CCT was 497.55 with an SD of 49.70. Seven patients (7.69%) had Descemet's membrane detachment (DMD) postoperatively, and the mean DMD at the highest point was 140.76µm. Five patients recovered with medical management; two were treated with anterior chamber air injection.

Discussions: Our study showed 9% corneal edema on postoperative day one, lower than other studies (18-44%). Diabetes mellitus type 2 was not associated with corneal edema in SICS cases, contrary to findings in phacoemulsification as reported in other studies. Pupillary manipulation was observed in only 2.2% of the cases, not being a risk factor. Surgeon experience significantly affected corneal edema, with trainee surgeons reporting more cases (44.5%, P=0.004). Hard cataracts (71.4%) caused higher endothelial damage, particularly in nuclear sclerosis grade NS5 (27.47%). The study underscores planning surgery based on cataract hardness, surgeon expertise, and proper intraoperative techniques to minimize complications.

Conclusion: Postoperative corneal edema following cataract surgery is a known complication usually resolved by medical management. More excellent surgical experiences with a shorter duration of surgery and proper instrumentation were associated with reduced early postoperative corneal edema. Early detection and classification of DMD with the help of AS-OCT for those requiring medical and surgical management aid recognize the clinically relevant DMD. Thus, a timely switch to surgical management helps maintain vision in patients with DMD.