Abstract
Purpose :
Pterygium translational research requires a standardized and reliable animal model, yet existing scientific literature lacks a comprehensive portrayal of the natural progression of induced lesions. This study seeks to set the clinical features of the evolution of a pterygium-like induced lesion in a rabbit model.
Methods :
Twenty-two male New Zealand rabbits were treated following ARVO statements. A subconjunctival injection of 20,000 NIH 3T3 cells in 10 ml of extracellular matrix (Matrigel) was administered in the superotemporal quadrant of the left eye, 5 mm close to limbus. The right eye was used as a non-treated control. The clinical appearance of the eyes was evaluated with digital photographs at follow-up days (1,7,10, 15, 18 and 23) and assessed on a scale: Grade 0, normal; Grade 1, slight changes; Grade 2, moderate changes; Grade 3, severe changes; and Grade 4, chronic changes. Area of affected conjunctiva was evaluated with ImageJ Software.
Results :
13 out of 22 eyes (60%) developed pterygium-like lesions. On day 1 follow-up period (Fig 1A), eyes showed a normal conjunctiva (grade 0). By day 7 (Fig 1B) and 10 (Fig 1C), conjunctival hyperemia, tortuous vessels and an elevated lesion close to limbus was observed (grade 3). On day 15 (Fig 1D), conjunctival hyperemia decreased, and the lesion's elevation lessened (grade 2). Subsequently, at day 18 (Fig 1E), there was mild elevation of the tissue with fine conjunctival vessels (grade 1). At the study’s conclusion (Fig 1F), a yellowish elevated lesion with no conjunctival injection was observed (grade 4). Hyperemia areas were 10.87± 4 mm2; 9.88 ± 5 mm2; 5.40 ± 1 mm2; 4.24 ± 2 mm2; 2.92 ± 2 mm2 on day 7, 10, 15, 18 and 23 respectively. Results show a pattern of lesion development, where most evolved from acute inflammation to a chronic lesion similar to human pterygium. Lesions proved to be non-invasive by not extending to the cornea.
Conclusions :
The key clinical features of a pterygium-like induced lesion involve a five-stage progression marked by an acute inflammatory phase that peaks on day 7 and culminates in a chronic pterygium-like lesion by day 23. This animal model describes induced pterygium progression suitable for translational research in ophthalmology. Histopathological analysis will reveal shared features with human pterygium.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.