Dynamic changes in retinal and choriocapillaris vascular density post-laser photocoagulation in diabetic retinopathy.

OBJECTIVES

To evaluate the changes in vascular density of the retina and choriocapillaris (CC) using swept-source optical coherence tomography angiography (SS-OCTA) after retinal laser photocoagulation in patients with diabetic retinopathy (DR).

METHODS

This prospective observational study included 45 eyes from 45 patients, comprising 20 with severe nonproliferative DR and 25 with proliferative DR. SS-OCTA images of the photocoagulation-treated areas were acquired before laser photocoagulation and at 1 h, 1 week, and 1 month follow-ups. Vessel densities of the superficial capillary plexus (SCP), deep capillary plexus (DCP), and CC were analysed in the laser spot area (LSA), total area (TA), and non-laser spot area (NLSA).

RESULTS

At baseline, the vascular density of the CC within the LSA was 65.4 ± 5.0%. This significantly decreased at 1 h after laser photocoagulation, followed by gradual recovery at 1 week and 1 month. However, the vascular density remained significantly lower than baseline at 1 month (all P < 0.001). The CC vessel density in the NLSA showed a similar trend but was not significantly different from baseline at 1 month (P = 1.000). The SCP vessel density in the LSA was 25.7 ± 3.1% at baseline, increased at 1 h after laser therapy, and then decreased at 1 week and 1 month. The DCP showed a decreasing trend from baseline through 1 h, 1 week, and 1 month after laser photocoagulation.

CONCLUSIONS

Retinal laser photocoagulation affects the CC, SCP, and DCP differently, enhancing our understanding of the mechanisms behind laser photocoagulation.