Effect of uncomplicated phacoemulsification on the central retina in diabetic and non-diabetic subjects

Background The purpose of this study was to evaluate the subclinical influence of uncomplicated cataract surgery on foveal thickness and volume in the early postoperative period. Methods In a prospective study, 108 eyes were assessed by optical coherence tomography preoperatively and 1 day, 1 week and 4 weeks after uncomplicated small incisional phacoemulsification with endocapsular intraocular lens (IOL) implantation under topical anesthesia. The study included 24 eyes of diabetic patients. Eyes with diseases predisposing them for postoperative macular edema, preexisting macular edema, and eyes that developed cystoid macular edema during follow-up were excluded. Main outcome measures were minimal foveal thickness (MFT) and foveal volume. Secondary outcome measure was VA. Results Visual acuity (LogMAR) increased significantly (p < 0.001) from 0.43 +/- 0.21 to 0.11 +/- 0.15 4 weeks after surgery, with a significantly (p=0.001) higher increase in VA for nondiabetic subjects. MFT increased from 183 +/- 27 mu m preoperatively to 191 +/- 37 mu m 4 weeks after surgery (p=0.001), with diabetic patients showing a tendency toward a more pronounced increase in minimal retinal thickness than nondiabetic subjects (p=0.058). One day and 1 week after surgery, MFT measurements were not significantly different from preoperative results. Foveal volume showed a significant increase at 1 week and 4 weeks after surgery (p < 0.001), independent of the presence of diabetes (p=0.565). The proportion of patients exhibiting subclinical macular swelling was about 1/5 in the nondiabetic group and 1/3 in the diabetic group. Mean duration of surgery was 11.5 +/- 6.6 min. Conclusion Foveal thickness and foveal volume demonstrate a subclinical increase within 4 weeks after uncomplicated cataract surgery in up to 1/3 of the patients. The amount and frequency of early postoperative subclinical retinal thickening was higher than expected.