Purchase this article with an account.
Christine Diane Harman, Andras M Komaromy; Biometric parameters and myopia in a canine model of open-angle glaucoma (OAG). Invest. Ophthalmol. Vis. Sci. 2020;61(7):3416.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To assess biometric parameters and refractive errors in beagle-derived dogs with Weill-Marchesani syndrome (WMS)-related OAG due to a G661R missense mutation in ADAMTS10.
A-scan parameters were measured in pre- and post-glaucomatous ADAMTS10-mutant (n=78) and normal control dogs (n=24) between 0.4 and 10.8 years of age (median ages: 25.6 and 31.1 respectively): anterior chamber depth (ACD), lens thickness (LT), vitreal chamber depth (VCD), and axial length (AXL). Refractive errors were measured in a subset of dogs (27 mutants, 11 normals) by streak retinoscopy. A total of 589 A-scans and 78 refractions were performed. Parameters were compared between groups by Student t-test with significance set at p≤0.05. Spearman’s correlation coefficients were calculated between A-scan parameters and refractive errors and age, respectively.
Regardless of age, A-scan parameters differed significantly between ADAMTS10-mutant and normal control dogs: AXL (21.22 ± 0.88mm vs. 20.62 ± 0.52mm; p≤0.001), LT (7.21 ± 0.31mm vs. 6.93 ± 0.27mm; p≤0.001), and VCD (9.56 ± 0.56mm vs. 9.34 ± 0.31mm; p≤0.001). AXL, LT, and VCD are significantly larger in ADAMTS10-mutant vs. normal dogs already at 1-2 years of age, before the increase in intraocular pressure (IOP) and development of OAG in mutants: AXL (21.13 ± 0.52mm vs. 20. 79 ± 0.58mm; p=0.003), LT (7.14 ± 0.30mm vs. 7.06 ± 0.20mm; p=0.013), and VCD (9.59 ± 0.57mm vs. 9.34 ±0.24mm; p≤0.001). ACD does not become significantly larger in mutant dogs until >4 years of age (4.91 ± 0.77mm vs. 4.37 ± 0.35mm; p=0.009), when clinical detectable OAG is present. There was a significant difference in refractive errors between mutant and normal dogs (-5.4 ± 1.48D vs. -0.2 ± 0.63D; p≤0.001) with mutant eyes being highly myopic. Age correlated to refractive error weakly in mutant (0.11) and moderately negative in normal dogs (-0.55). In contrast, correlation between AXL and age was much weaker in normal (0.08) vs. mutant dogs (0.49).
Mutant eyes are significantly longer than normal eyes due to a deeper VCD resulting in high degree of myopia even before the increase in IOP. Weak correlation between refractive error and biometric parameters suggest that lens position may have an important role in myopia. The increased LT may be due to ADAMTS10-mutation-related lens zonular dysplasia and weakness.
This is a 2020 ARVO Annual Meeting abstract.
This PDF is available to Subscribers Only