Abstract
Purpose :
To examine the ocular refraction parameters of young rhesus and cynomolgus monkeys in the natural growth and development conditions of China.
Methods :
In this cross-sectional study, 26 rhesus monkeys and 12 cynomolgus monkeys, aged 2-5 years old, were selected. Spherical equivalent (SE), axial length (AXL), anterior chamber depth (ACD), lens thickness (LT) and vitreous chamber depth (VCD) were measured by automatic computer optometry and A-scan ultrasonography. A fundus camera and OCT were also performed to exclude ocular diseases. T-test was used to compare the continued normal distribution data. Wilcox on Rank-Sum test was used to compare the non-normal distribution data. Spearman’s correlation and logistic regression analysis were used to identify the factors associated with AXL. P<0.05 was considered statistically significance.
Results :
Two rhesus monkeys were excluded for abnormal eye development. For remaining 24 rhesus monkeys, SE was 0.01±1.08 D, AXL was 19.57±0.85 mm, ACD was 3.36±0.77 mm, LT was 4.08±0.74 mm, VCD was 12.11±0.55 mm for right eyes and 0.27±1.22 D, 19.59±0.84 mm, 3.59±1.23 mm, 4.22±0.66 mm, 12.11±0.72 mm for left eyes. For 12 cynomolgus monkeys, SE was -0.52±0.92 D, AXL was 18.24±0.56 mm, ACD was 3.59±0.27 mm, LT was 3.23±0.23 mm, VCD was 11.41±0.78 mm for right eyes and -0.38±1.03 D, 17.98±0.51 mm, 3.57±0.59 mm, 3.22±0.38 mm, 11.12±0.70 mm for left eyes. The SE of 48 rhesus monkeys eyes was 0.14±1.15D and -0.45±0.96 D for 24 cynomolgus monkeys eyes, there was a significant difference between the two groups (t=2.174, P<0.05). The AXL of 48 rhesus monkey eyes was 19.80±0.95 mm and 18.02±0.99 mm for 24 cynomolgus monkey eyes, there was a significant difference between the two groups (Z=-5.734, P<0.05). The AXL of 72 rhesus and cynomolgus monkeys’ eyes were included. Spearman’s correlation showed that ACD, LT, ACD, strain, gender, age and weight were statistically significantly associated with AXL (R=0.396, 0.558, 0.717, -0.681, -0.456, -0.421, 0.657, P<0.05). The results of logistic regression analysis showed that ACD, LT and VCD were statistically significantly associated with a longer AXL (Beta=0.663, 0.704, 0.669, P<0.05).
Conclusions :
This study found there was significant difference in SE and AXL between the rhesus and cynomolgus monkeys. ACD, LT and VCD were statistically significantly associated with axial elongation. The ocular parameters could provide a foundation for future research.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.