Glucocorticoid eye drops inhibit growth in the newborn rabbit

Aim: To investigate if postoperative treatment with dexamethasone eye drops has the capacity to affect longitudinal growth in newborn rabbits. Methods: Thirty‐four male and female rabbits had clear lens extraction performed in one eye at 3 wk of age and were then treated either intensively (group 1) or less intensively (group 2) with de‐escalating doses of dexamethasone eye drops for 8 wk (average doses 0.27 and 0.10 mg/kg body weight/day, respectively). The control group (group 3) received vehicle eye drops only. Body weight and crown–rump length were recorded every week. After 8 wk of treatment, all rabbits were killed and the left femur was measured. Results: Rabbits treated with dexamethasone eye drops gained weight slower (711±42 and 989±153 g weight increase for groups 1 and 2, respectively) than control animals (group 3; 1224±87 g weight increase; p<0.001 vs group 1, p<0.01 vs group 2). Longitudinal growth, determined as increase in crown–rump and femur lengths, was impaired by dexamethasone eye drops in a dose‐dependent way. Crown–rump length increased by 8.25±0.86, 10.90±1.19 and 15.35±1.31 cm in groups 1, 2 and 3, respectively (p<0.001 for all comparisons). At endpoint, i.e. after 8 wk of treatment, the average femur length was 6.36±0.21, 7.39±0.27 and 8.37±0.28 cm in groups 1, 2 and 3, respectively (p<0.001 for all comparisons).