Evaluation of the Effect of Phacoemulsification Surgery on Retinal and Choroidal Microvasculature in Diabetic Patients Using Optical Coherence Tomography Angiography

Abstract Aim To evaluate the effect of phacoemulsification surgery on retinal and choroidal microvasculature in diabetic patients using optical coherence tomography angiography. Settings and Design A prospective comparative case control study performed at the Ophthalmology department of Ain Shams University hospital, between November 2020 and November 2022. Methods and Material 50 eyes of 35 cataractous patients were included in this prospective study divided into two groups: the control group (25 eyes of 19 patients) and the diabetic group (25 eyes of 16 patients with mild non proliferative diabetic retinopathy). All patients underwent routine ophthalmic examination, OCT and OCTA scans of the macula before phacoemulsification surgery and 1week 1month, 3months and 6months after the surgery. Results The BCVA significantly improved in both group by ∼ 0.26 logMAR units in control and diabetic groups (p < 0.001 for both). the mean change in CST was 23.44±43.7 vs 13.6±22 um (p = 0.3) in the control group and the diabetic group, respectively but statistically insignificant. There was insignificant change in each group in all vascular parameters during the follow up period. In addition, there was insignificant difference between 2 groups at each visit in most vascular parameters of SVD, DVD, and choriocapillaris VD. On the other hand, the diabetic groups has significantly lower SVD of whole image and perifovea at 1 week than controls (42.92 ± 4.54 % vs 46.16 ± 3.98 %, p = 0.01 in whole image respectively) (44.29 ± 4.87 % vs 47.32 ± 3.85 %,p=0.018 in perifovea respectively). The diabetic group also showed significantly higher parafoveal DVD than the control group at 1 month postoperatively : 52.67 ± 4.00 vs 47.24 ± 9.85 % (p = 0.014) that levelled up on month 3 and 6 (p = 0.397, 0.538 respectively). the diabetic group showed lower CC VD of whole image than the control group at 1 week postoperatively: 70.60 ± 2.87 vs 72.22 ± 1.98 % respectively (p = 0.025), and also significantly lower CC VD of perifovea than the control group at 1 week: 71.19 ± 2.82 vs 72.72 ± 2.20 % (p = 0.038), 1 month: 71.08 ± 2.87 vs 72.78 ± 2.61 % (p = 0.033) and 3 months: 71.35 ± 2.63 vs 72.83 ± 2.52 %(p = 0.048). Those values levelled up at the last postoperative visit at month 6 (p = 0.152). Conclusion Phacoemulsification surgery may lead to the transient and mild reduction of choroidal blood flow in diabetic eyes rather than retinal blood flow. Most of choroidal and retinal vascular change happened in the perifoveal area within 1 week to 1 month postoperatively and rarely extended to 3months. Further research is needed to detect its influence on diabetic retinopathy progression.