Incidence, Clinical Features and Risk Factors for Cystoid Macular Oedema following Cataract Surgery: A Prospective Cohort Study

Introduction: Pseudophakic Cystoid Macular Oedema (PCME) remains an important cause of delayed visual recovery after cataract surgery. The use of Optical Coherence Tomography (OCT) has increased the detection of milder and subclinical postoperative macular oedema, making local incidence estimates and risk profiling clinically relevant. Aim: To estimate the incidence of PCME within 3 months after cataract surgery and to evaluate the clinical and operative risk factors associated with its occurrence. Materials and Methods: The present prospective cohort study was conducted in the Department of Ophthalmology, Adichunchanagiri Institute of Medical Sciences, BG Nagara, Karnataka, India, during a 12-month study period from January 2025 to January 2026. A total of 155 eyes of 155 patients aged 40 years and above undergoing small-incision cataract surgery or phacoemulsification were analysed. Baseline systemic and ocular variables, operative details, postoperative anterior chamber reaction, Best-Corrected Visual Acuity (BCVA), and OCT-derived central macular thickness were recorded. PCME was defined on OCT by intraretinal cystic changes with increased central macular thickness. Categorical variables were analysed by Chi-square test or Fisher’s exact test, continuous variables by Student’s t-test, and within-group CMT change by paired t-test after assessment of distribution. Exploratory multivariable logistic regression was used to identify associated predictors. A p-value of <0.05 was considered statistically significant. Results: PCME was identified in 18 of 155 eyes (11.6%). Diabetes mellitus, hypertension, operative duration >20 minutes, intraoperative complications, and anterior chamber inflammation grade ≥2 at one week were more frequent in the PCME group. Mean central macular thickness increased from 252±22 µm preoperatively to 320±25 µm at six weeks in eyes with PCME (p<0.001), whereas the change in non-PCME eyes was not statistically significant (250±20 µm to 240±18 µm, p=0.052). 3-month BCVA remained poorer in the PCME group (LogMAR 0.5±0.2 vs 0.3±0.1, p=0.008). In exploratory multivariable analysis, diabetes mellitus, operative duration >20 minutes, and intraoperative complications remained associated with PCME. Conclusion: OCT-detected PCME occurred in approximately one in nine operated eyes in this cohort. Diabetes mellitus, greater operative stress, and intraoperative complications were the strongest associated predictors. Early OCT surveillance may therefore be justified in eyes with a higher postoperative inflammatory or metabolic risk profile.