Macular and Choroidal Thickness Changes After Cataract Surgery in Diabetic and Non-diabetic Patients: A Prospective Optical Coherence Tomography (OCT) Study

TL;DR

This study compares how cataract surgery affects eye structures in diabetic and non-diabetic patients using OCT imaging.

Contribution

The study introduces a detailed OCT-based comparison of postoperative macular and choroidal changes in diabetic and non-diabetic patients.

Findings

Diabetic eyes showed greater central macular thickness increase and choroidal thinning after surgery.

Non-diabetic eyes thickened in choroidal thickness and recovered vision faster post-surgery.

SICS provided better retinal-choroidal stability in diabetic eyes compared to PHACO.

Abstract

Purpose

The purpose of the study is to compare postoperative changes in central macular thickness (CMT) and subfoveal choroidal thickness (SFCT) using spectral-domain optical coherence tomography (SD-OCT) in diabetic and non-diabetic eyes and to assess the influence of glycemic status and surgical technique.

Methods

This prospective study included 130 eyes of 130 patients aged 50-70 years with senile cataract, comprising 65 diabetic eyes and 65 non-diabetic eyes. All underwent uneventful cataract surgery by either phacoemulsification (PHACO) or small-incision cataract surgery (SICS). Systemic parameters-fasting blood sugar (FBS), postprandial blood sugar (PPBS), and glycated hemoglobin (HbA1c)-along with detailed ocular evaluations were recorded. OCT was performed preoperatively and at postoperative day 1, week 1, and week 4 to assess CMT, SFCT, and microstructural changes, including cystic spaces, retinal pigment epithelium (RPE) alterations, and foveal contour.

Results

Mean age was comparable between groups (p = 0.59). Diabetic eyes showed significantly higher FBS, PPBS, and HbA1c values (p < 0.001). Visual improvement occurred in all eyes, but non-diabetic eyes recovered faster (day 1: 0.45 vs. 0.54 logarithm of the minimum angle of resolution (LogMAR), p = 0.002; week 1: 0.28 vs. 0.38, p < 0.001), with comparable vision by week 4 (p = 0.078). Diabetic eyes demonstrated a greater rise in mean CMT (265.6 → 274.0 µm) than non-diabetic eyes (255.0 → 269.0 µm; p < 0.05). SFCT showed opposite trends-non-diabetic eyes thickened (265 → 275 µm), whereas diabetic eyes thinned (229 → 223 µm; p < 0.001). At week 4, 15 of 65 diabetic eyes (23.1%) exhibited cystic spaces and RPE alterations. PHACO provided faster visual recovery but was associated with greater CMT rise and SFCT thinning, whereas SICS showed relatively better postoperative structural stability.

Conclusion

Cataract surgery improved visual acuity in all eyes; however, diabetic eyes exhibited higher postoperative CMT and reduced SFCT, suggesting increased microvascular fragility. Integration of OCT-based parameters with HbA1c enhances postoperative risk assessment. PHACO offers faster recovery in non-diabetic eyes, while SICS may ensure better retinal-choroidal stability in diabetic eyes.