Abstract
Purpose :
To compared changes in minimal rim width (BMO-MRW), retinal nerve fiber layer thickness (RNFLt) and inner retinal function revealed by photopic negative response (PhNR) in non-human primate model of laser-induced unilateral experimental ocular hypertension (EOHT) or spontaneous ocular hypertension (SOHT).
Methods :
This study included 55 male cynomolgus monkeys, 13 monkeys with binoculus spontaneous hypertension, which were found in the ophthalmological screening of more than three hundred animals, 14 monkeys in which experimental glaucoma were unilaterally produced and 28 healthy controls. All eyes underwent testing optical coherence tomography (OCT) scans using the Glaucoma Module Premium Edition. The software enables measuring of RNFLt around the optic nerve head and BMO-MRW. Functional analyses utilize full-field flash ERG, brief red flashes on a rod-suppressing blue background used to assess PhNR.
Results :
The mean IOP was 24.6 ± 3.4 mmHg and 39.6 ± 17.9 in SOHT and EOHT group respectively. There were no significant differences in age (P = 0.131), central corneal thickness (P = 0.321) or axial length (P = 0.399) among three groups. The RNLFt was significantly decreased in EHOT and SOHT group by 38.6% and 8.3% compared with healthy control. The BMO-MRW was significantly reduced by 51.9% in EOHT group compared to healthy control, but did not differ between the SOHT and healthy control. Compared with the healthy control, the amplitudes of PhNR and a-wave were significantly reduced in the EOHT by 24.2%, 21.3% respectively, but not in SOHT group. In EOHT eyes, the decreasing of MRW relative to control eyes was proportionally greater, in general, than the relative thinning of RNFLt and the relative reduction in amplitude of PhNR.
Conclusions :
In a NHP model of EOHT, significant retinal ganglion cell structural and electrophysiological losses were found. Although the SOHT electrophysiological retinal function has not changed significantly, it might need to take longer to observe. Both model for clinical research which could be useful in in assessing glaucomatous neuropathy.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.