Abstract
Purpose :
Pterygium has no pharmaceutical treatment; surgery is the current standard of care. There is an unmet need for pharmaceutical therapies to help reduce surgical costs. We found that the Siempreviva (SV) sap reduced inflammatory markers and decreased the viability of pterygium fibroblasts in vitro. We used an in vivo model to test SV's efficacy in treating pterygium-like growth.
Methods :
A pterygium-like lesion induction model was created using 32 New Zealand rabbits that were treated in accordance with ARVO standards. The rabbits were split into four groups (high and low doses of SV in hypromellose or hyaluronate) and administered bilateral subconjunctival supratemporal injections of 20,000 NIH3T3 cells and 5 uL of matrigel. They were treated in the right eye with one formulation drop every 8 hours for 23 days post-induction. Both eyes of each rabbit were photo-documented. We created a clinical scale with four categories: 0 for normal conjunctiva, 1 for mild changes (subtle tissue elevation with fine, thin conjunctival vessels), 2 for moderate changes (conjunctival hyperemia and less elevated lesion), 3 for severe changes (conjunctival hyperemia with tortuous vessels and an elevated lesion near the limbus), and 4 for chronic changes (yellowish elevated lesion without conjunctival injection). This allowed us to assess the efficacy of the various formulations.
Results :
Without treatment, 53.8% of the eyes formed 3 grade lesions on day 7, and developed 4 grade lesions on day 23. The hypromellose eyedrop groups, both high and low doses, exhibited a similar tendency to the untreated lesion with 50% of each group developing 4 grade lesions by day 23. In the hyaluronate groups, 75% of each group showed grade 1 lesions at the beginning, but in the low-dose group, 50% developed chronic changes, and the rest were downgraded to 0 grade lesions by day 23. In contrast, 75% of the high-dose hyaluronate group had 0 or 1 grade lesions at the end of the experiment.
Conclusions :
Hyaluronate eyedrops with high-dose SV showed therapeutic effect for pterygium-like lesions. They could bring insight into the future development of pharmacological therapies for pterygium treatment.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.