Evaluation of the effects of sympathomimetic and parasympatholytic agents on ocular parameters, retinal vascular density and choroid thickness in healthy young adults

PURPOSE: To evaluate the effect of %2,5 phenylephrine and %0,5 tropicamide on retinal vascular density, foveal avaskuler zone, foveal density, choroidal thickness and ocular biometry parameters MATERIAL-METHOD: 32 right eyes of 32 healthy individuals who applied to Manisa Celal Bayar University Faculty of Medicine Department of Ophthalmology were included in the study. All patients underwent detailed ophthalmologic examination. Patients were randomly instilled 0.5% tropicamide, 2.5% phenylephrine or placebo (0.15% sodium hyaluronate) drops on three different days. Optical biometry with Lenstar LS900 (Haag Streit AG, İsviçre) and optical coherence tomography angiography (OCTA) with AngioVue (RTVue-XR, Fremont, California, ABD) were performed at each admission and repeated after the drops. All parameters were compared statistically and p <0.05 was considered significant. RESULTS: Twenty (62.5%) of the cases were female and 12 (37.5%) were male. The mean age of the patients was 23.59 ± 0.75 years. The mean refraction values of the cases were evaluated as -1,02 ± 1,02D (-3,50, 0). There was no statistically significant difference in axial length and central corneal thickness measurements before and after placebo, phenylephrine and tropicamide drops respectively. (p=1,00, p=0,616 p=902) (p=0,931, p=0,944 p=0,074). Anterior chamber depth did not change significantly after placebo (p = 0.244), whereas phenylephrine and tropicamide showed a significant increase after drops. (p=0,001 p<0,001) Lens thickness measurements showed a significant decrease after tropicamide drop. (p<0,001) There was no significant change after placebo and phenylephrine drops. (p=0,321 p=0,313) Choroidal thickness decreased significantly at 3000 µm temporal and 1500 µm nasal of fovea after placebo. (p=0,014 p=0,013) No statistically significant difference was detected in the other areas with placebo drops. There was a significant decrease in choroidal thickness at 3000 µm temporal of fovea after phenylephrine drop. (p=0,014) There was no statistically significant difference in other areas. Choroidal thickness decreased significantly at 1500 and 3000 µm temporal and nasal of fovea and subfoveal area after tropicamide. (p=0,002 p<0,001 p=0,036 p=0,032 p=0,017) No significant changes were observed at the 500 µm nasal and temporal of the fovea. In the evaluation of superficial capillary plexus vascular density after placebo drops; significant decrease was observed in the whole area, parafoveal area and perifoveal area, respectively. (p=0,036 p=0,018 p=0,047) In deep capillary plexus measurements, there was no significant difference in vascular density in the whole area, parafoveal and perifoveal areas. In deep and superficial capillary plexus measurements after phenylephrine, there was no significant difference in vascular density in the whole area, parafoveal and perifoveal areas. In the evaluation of superficial capillary plexus vascular density after tropicamide; significant decrease was observed in the whole area and perifoveal area, respectively. (p=0,033 p=0,042) In deep capillary plexus measurements after tropicamide, there was no significant difference in vascular density in the whole area, parafoveal and perifoveal areas. After placebo, phenylephrine and tropicamide drops respectively, there was no significant difference between FAZ area, foveal density and FAZ circumference. (p=0,726 p=0,521 p=0,472) (p=0,673 p=0,642 p=0,688) (p=0,704 p=0,159 p=0,069) CONCLUSION: After 2.5% phenylephrine and 0.5% tropicamide drops, no significant difference was found on the FAZ area and foveal density. There was no significant change in macular vascular density after phenylephrine, but there was a significant decrease in superficial capillary plexus after placebo and tropicamide. Choroidal thickness did not change significantly after placebo and phenylephrine but decreased after tropicamide. Optical biometry measurements showed no significant changes in axial length and central corneal thickness. Anterior chamber depth was significantly increased after phenylephrine and tropicamide drops. Lens thickness decreased significantly after tropicamide.