Increase in rabbit corneal curvature by heated ring application

Area of Science:

• Ophthalmology
• Corneal Research
• Veterinary Ophthalmology

Background:

• Corneal curvature is a critical factor in refractive error.
• Methods to alter corneal shape are of significant interest in ophthalmology.
• Understanding the mechanisms of corneal tissue response to thermal stimuli is important.

Purpose of the Study:

• To investigate the induction of increased corneal curvature using heated brass rings in living rabbits.
• To determine the transient nature and reversibility of heat-induced corneal curvature changes.
• To explore the underlying mechanism and safety profile of this procedure.

Main Methods:

• Application of heated brass rings (approximately 98°C) to the corneas of 19 living rabbits.
• Measurement of corneal curvature changes (in diopters) compared to non-treated fellow eyes.
• Histological examination to understand the mechanism and assessment of corneal ulceration incidence.

Main Results:

• A peak average increase of 10.5 D in corneal curvature was observed.
• The induced curvature change was transient, returning to baseline within two to three weeks.
• A low incidence of corneal ulceration was noted, with significant ulceration rare below 110°C.
• The mechanism involved the creation of a rigid, desiccated pseudo-limbus, which resolved upon rehydration.

Conclusions:

• Heated brass rings can induce a transient increase in corneal curvature in rabbits.
• The effect is reversible and mediated by temporary limbal tissue dehydration.
• The procedure appears safe at temperatures around 98°C, with ulceration risk increasing significantly above 110°C.