Abstract
Purpose :
We previously reported differential gene expression of Bone morphogenic protein 2 (Bmp2) in guinea pig retinal pigment epithelium (RPE) after 1-day of hyperopic defocus, imposed with a contact lens (CL). To obtain insight into the temporal profile of these BMP2 gene expression changes, the effects of 1-day and 1-week induction and recovery from CL-induced myopia on Bmp2 gene expression in guinea pig RPE were compared.
Methods :
To induce myopia, 2-week-old pigmented guinea pigs (New Zealand strain, n = 6) wore monocular -10 diopter (D) rigid gas-permeable (RGP) CLs for one week; fellow eyes served as controls. Ocular measurements were made at baseline and again after 1 week of CL wear, when the treatment was also terminated. Axial length (AL) and choroidal thickness (ChT) data were collected using optical biometry (Lenstar), and spectral domain optical coherence tomography (SD-OCT), respectively. RPE samples were collected from treated and fellow eyes after 1 day and 1 week of CL wear, and after 1 day of recovery from 1 week of CL wear (n = 4 at each timepoint), and extracted RNA samples subjected to quantitative real-time PCR (qRT-PCR) analysis to assess Bmp2 gene expression.
Results :
Mean interocular differences (treated-fellow) reflect significant treatment-induced AL increases (0.13 ± 0.04 mm, p < 0.001), and ChT thinning (−6.25 ± 3.92 um, p = 0.011), after 1 week of CL wear. RPE-Bmp2 gene expression was significantly decreased in treated eyes after both 1 day and 1 week of CL wear (82.9 ± 6.4 %, p = 0.031 and 79.3 ± 10.8 %, p = 0.013, respectively), yet was significantly increased after just 1 day of recovery (125.5 ± 11.4 %, p = 0.021).
Conclusions :
The contrasting bidirectional changes in RPE-Bmp2 gene expression, during the induction of and recovery from, myopia are consistent with previous findings by our group in chicks and support a role for BMP2 in eye growth regulation.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.