Evaluation of patients who received laser photocoagulation therapy for retinopathy of prematurity using optical coherens tomography angiography

Aim: Our aim is to compare long term macular structural diferences in in preterm children without a history of retinopathy of prematurity (ROP), children treated with laser photocoagulation (LPC), children with retinopathy of prematurity who regress spontaneously and children born at term by optical coherens tomography angiography (OCTA). Material and Method: The study included 35 eyes of 20 patients who were diagnosed with ROP and underwent LFC, 35 eyes of 20 patients who regressed without treatment and 38 eyes of 20 premature infants who did not develop ROP in their follow-ups. Also, 37 eyes of 21 healthy patients born at term were taken as control group. Following a comprehensive ophthalmological examination, 6x6 mm HD Angio Retina OCTA measurements were taken. The vessel density of the superficial capillary plexus (SCP-VD) and deep capillary plexus (DCP-VD) was determined in percent. The central macular thickness (CMT) was automatically analyzed. The parameters related to the foveal avascular zone were obtained by selecting the FAZ section in the device. Subfoveal choroidal thickness (SFCT) was measured manually from the subfoveal region in the images taken by selecting the spectral domain OCT (SD-OCT) raster module of the OCTA device. Foveal diameter and depth of foveal cupping were measured manually from the same images. The presence of internal limiting membrane was noted. Results: In comparison to the premature and control groups, fovea DCP-VD and YCP-VD were higher in the L-ROP and R-ROP groups, while whole DCP-VD and YCP-VD were lower. It was observed that FAZ area, perimetry and FD values were decreased in the L-ROP and R-ROP groups compared to the premature and control groups. It was evaluated that CMT was significantly higher in L-ROP and R-ROP groups compared to the premature and control groups. Foveal pit depth (FPD) and foveal diameter were also found to be decreased in L-ROP and R-ROP groups compared to the premature and control groups. A reduced FAZ area was found to be associated with increased CMT and foveal vessel density. Also, a positive correlation was found between CMT and fovea deep and superficial capillary plexus vessel density. It was determined that visual acuity was negatively correlated with CMT and foveal vessel density, and positively correlated with FAZ area. Conclusion: Even if it regresses with therapy, retinopathy of prematurity impairs the macula's morphological and vascular development, and changes in the vascular density and FAZ area are irreversible. These modifications have an insignificant effect on the final visual acuity. Key words: retinopathy of prematurity, OCTA, LPC, FAZ, vascular density