Ophthalmic diagnostic tests in captive red-footed tortoises (Chelonoidis carbonaria) in Salvador, northeast Brazil.

Abstract

The aim of this study was to establish normal ophthalmic parameters for select diagnostic tests in red-footed tortoises (Chelonoides carbonaria). A total of 52 animals, approximately 20-30years old, were studied. Ophthalmic diagnostic tests included culturing of the normal conjunctival bacterial flora in summer and winter, evaluation of tear production using Schirmer tear test (STT) and endodontic absorbent paper point tear test in two different environmental temperatures (EAPPTT-1 at 32°C and EAPPTT-2 at 18°C), cytology of conjunctival cells, B-mode ultrasonography, measurement of palpebral fissure length (PFL), and applanation tonometry (in two different positions). In both seasons, Gram-positive bacteria were predominant. Median (± IQR/2) STT was 12.0±3.5mm/min, EAPPTT-1 was 15.9±0.7mm/15s, and EAPPTT-2 was 15.4±0.4mm/min (OD) and 17.8±1.0mm/min (OS). Anterior chamber depth was 1.0±0.1mm, lens axial length was 2.3±0.1mm, vitreous chamber depth was 4.3±0.2mm, and axial globe length was 7.7±0.3mm. PFL was 11.7±1.7mm. Intraocular pressure was 11.5±2.8mmHg for males and 14.0±3.5mmHg for females (dorsoventral position) and 18.0±3.2mmHg for males and 24.1±3.0mmHg for females (ventrodorsal position with inclination of 45°). The ophthalmic parameters reported here can aid in the diagnosis of eye diseases in red-footed tortoises (Chelonoides carbonaria).