Effects of testosterone on intraocular pressure, thicknesses of retinal nerve fiber layer, ganglion cell complex, macula and on ocular blood flow in female-to-male transgender persons.

Purpose: To compare the effects of testosterone on intraocular pressure (IOP), thicknesses of retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), macula and on ocular blood flow between female-to-male transgender (FMT) persons who use testosterone and healthy women and healthy men.

Method: The study included 39 eyes of 20 FMT(Group 1), 40 eyes of 20 healthy women (Group 2), and 42 eyes of 21 healthy men (Group 3). In all subjects, RNFL, GCC and, macular thicknesses (MT) were measured by optical coherence tomography (OCT). Ocular blood flow was measured by Color Doppler Ultrasonography in all subjects.

Results: IOP levels in FMT were significantly higher than men (p = 0.025). Superior (Sup), inferior (Inf) thicknesses of parafovea, and nasal thickness of perifovea in FMT were significantly higher than the Group 2 (p = 0.024, p = 0.037, p = 0.018). Sup thickness of perifovea in FMT was significantly higher than Group 3 (p = 0.011). Inf thickness of perifovea in FMT was significantly higher than Group 2 and 3 (p = 0.038, p = 0.002). Mean thickness of RNFL Inf in FMT was significantly higher than the Group 2 and 3 (p = 0.039, p = 0.032). Avg and Inf thicknesses of GCC in FMT were significantly higher than group 2 (p = 0.02, p = 0.005). In correlation test, systole/diastole ratio(S/D) in ophthalmic artery (OA) (r = 0.504, p = 0.028) and Inf thickness of perifovea (r = 0.485, p = 0.035) were positively correlated with the serum levels of testosterone in FMT.

Conclusions: We found that the use of supraphysiologic testosterone dose increased IOP and the thicknesses of macula, RNFL, and GCC in FMT. Serum testosterone level was positively correlated with S/D ratio in the OA.