Background: Diabetic retinopathy (DR) is a major cause of visual impairment globally, with alterations in choroidal thickness (CT) playing a significant role in its pathophysiology. The impact of cataract surgery on CT in diabetic patients without macular edema is not well understood. This study is aimed to investigate CT changes following cataract surgery in DR patients without macular edema compared to non-diabetic controls.

Methods: In this prospective interventional study, 108 patients aged 50–80 years undergoing phacoemulsification cataract surgery were included—54 with DR without macular edema (case group) and 54 non-diabetic individuals (control group). Comprehensive ophthalmic evaluations, including best-corrected visual acuity and intraocular pressure, were performed preoperatively and at 3 months postoperatively. Choroidal thickness was measured using spectral-domain optical coherence tomography. Statistical analyses involved paired t-tests within groups and independent t-tests between groups, with significance set at p < 0.05.

Results: The case group showed a significant decrease in mean CT from 252.685 ± 33.882 μm preoperatively to 234.481 ± 32.840 μm postoperatively (p < 0.001). In contrast, the control group exhibited a significant increase from 273.704 ± 18.792 μm to 284.519 ± 20.733 μm (p < 0.001). The difference in CT changes between groups was statistically significant (p < 0.001). Baseline and postoperative CT were significantly thinner in the diabetic group compared to controls (p < 0.001).

Conclusion: Cataract surgery leads to a significant decrease in choroidal thickness in DR patients without macular edema, while causing an increase in non-diabetic individuals. These findings suggest that diabetic patients may be more susceptible to choroidal thinning post-surgery, potentially influencing DR progression. Awareness of these effects is crucial for optimizing postoperative management in diabetic patients.