Intraocular Amphiregulin antibody and axial elongation in nonhuman primates.

Purpose: To examine the effect of intraocularly applied amphiregulin antibody on physiological axial elongation in young nonhuman primates.

Methods: The experimental study included six male 12-months-old macaque nonhuman primates (body weight:2.46 ± 0.25kg;range:2.20-2.90kg). In the experimental group (n=3 animals), three intravitreal injections of amphiregulin antibody (100μg/50μl) were applied to the left eyes at intervals of 4-6 weeks, and injections of phosphate buffered solution (50μl) were applied to the right eyes. Three other animals were assigned to a blank control group.

Results: During the study period of 23.6 weeks, axial length in the experimental group did not change in the left eyes (18.91 ± 0.37mm to 18.94 ± 0.67mm;=0.90), while it linearly increased in the right eyes (18.87 ± 0.38mm to 19.24 ± 0.53mm;=0.056) and in the control group (left eyes:19.15 ± 0.22mm to 19.48 ± 0.22mm;=0.009; right eyes:19.17 ± 0.15 mm to 19.46 ± 0.23 mm;=0.024). The interocular difference in axial elongation increased in the experimental group from -0.11 ± 0.12mm at 4 weeks after baseline to -0.34 ± 0.15mm at the study end, while in the control group, the interocular side difference did not change significantly (from 0.01 ± 0.10 mm to 0.03 ± 0.08 mm;=0.38). The difference in the interocular difference in axial elongation between the two groups was significant at 8 weeks (=0.01), 15 weeks (=0.007), and at study end (=0.02). The interocular difference in axial length correlated with the interocular difference in vitreous cavity length (standardized regression coefficient beta:0.85;<0.001). The interocular axial length difference was inversely associated with the interocular refractive error difference (beta:-0.49;<0.001).

Conclusions: Intraocularly applied amphiregulin antibody (100μg) reduced the physiological ocular axial elongation in juvenile nonhuman primates.