Evaluation of visual acuity, macular status, and subfoveal choroidal thickness changes after cataract surgery in eyes with diabetic retinopathy

Abstract

Purpose: Progression of diabetic macular edema has been reported as a common cause of poor visual acuity recovery after cataract surgery in patients with diabetes. Despite being responsible for the blood supply to the outer retina, the role of the choroidal layer in the pathogenesis of diabetic retinopathy (DR) is not yet understood. Our objective is to characterize macular and subfoveal choroidal thickness changes after cataract surgery in eyes with DR.

Methods: Thirty-five eyes with clinically significant cataract of patients with DR were divided into three groups based on clinical and optical coherence tomography findings: patients with DR without macular edema, patients with DR and macular thickening detected on optical coherence tomography, and finally patients with clinically significant macular edema. All cases were submitted to ophthalmologic examination and spectral domain optical coherence tomography 1 week before cataract surgery and repeated 1 month after surgery. Patients with preoperative clinically significant macular edema were treated with intravitreal bevacizumab at the time of surgery.

Results: All groups showed a significant increase in visual acuity 1 month after surgery (P < 0.001). Mean foveal thickness increased significantly in all groups, including controls (P = 0.013), except in patients who were simultaneously treated with intravitreal bevacizumab (P = 0.933). An increase of maximum macular thickness of at least 11% was found in 25.7% of the DR eyes, but no such increase occurred in the control eyes. No significant change was verified for subfoveal choroidal thickness in any of the studied groups.

Conclusion: Surgical inflammation associated with cataract surgery caused a significant increase of macular thickness in control and DR eyes that were not treated with intravitreous bevacizumab. Such macular changes were not accompanied by subfoveal choroidal thickness changes in any of the study groups, suggesting that the changes in macular thickness associated with the surgery are not related to changes in choroidal thickness and that there is no relation between inner blood-retinal barrier status and diabetic choroidal angiopathy.