OPHTHALMIC EXAMINATION FINDINGS AND INTRAOCULAR PRESSURE MEASUREMENTS IN SIX SPECIES OF ANURA

PREVALENCE OF OCULAR ABNORMALITIES AND NORMAL DIAGNOSTIC PARAMETERS IN TWO GROUPS OF PANAMANIAN GOLDEN FROGS (ATELOPUS ZETEKI)

Panamanian golden frog (PGF) (Atelopus zeteki) is a critically endangered species. The Maryland Zoo in Baltimore houses two groups of PGF originating from distinct geographic locations as an assurance colony, with the goal of upholding genetics for future release of individuals back to their native environment. The purpose of this cross-sectional study was to characterize the prevalence of ocular abnormalities in these two zoo-housed populations of PGF as well as to establish normal parameters for selected diagnostic tests in these groups. Twenty-five females and 25 males were randomly selected from each group (100 PGF; 200 eyes in total) to undergo ocular examination using slit lamp biomicroscopy and direct ophthalmoscopy. Endodontic absorbent paper point test (EAPPT) and intraocular pressure (IOP) and Rose Bengal stain diagnostic tests were also performed. Reference ranges for tear production (EAPPT, 0.5-3 mm/min) and IOP (14-26 mmHg) were calculated in the nondiseased PGF eyes (n = 160 eyes). Rose Bengal stain uptake was negative on all eyes. In total, 40 eyes of 30 PGF were found to have some form of ocular abnormality (28% of PGF, 20% of eyes). The most frequently observed ocular abnormalities were cataract (9% of PGF, 6% of eyes) and keratitis (nonlipid keratopathy; 10% of PGF, 5.5% of eyes). There was no significant difference in overall ocular abnormality prevalence between the two groups studied (P = 0.37) or between the sexes (P = 0.76). The median age of an eye with cataract and keratitis (nonlipid keratopathy) was 10.35 and 7.7 yr, respectively. Ocular abnormalities are common in these two populations of PGF. Documentation of these ocular abnormalities and establishment of diagnostic reference ranges have not previously been published and may be important for maintaining the health of this endangered species.

Ophthalmic findings and parameters in Western tiger salamanders (Ambystoma mavortium) from northern Colorado

OBJECTIVE

The aim of this study was to document ophthalmic examination findings and provide reference values for ocular examinations and diagnostics in clinically normal Western tiger salamanders (Ambystoma mavortium) and to evaluate the mydriatic effect of a topical rocuronium bromide and identify any adverse effects.

ANIMALS STUDIED

Sixteen Western tiger salamanders.

PROCEDURE

A complete ophthalmic examination, including intraocular pressure via rebound tonometry [iCare® TonoVet (dog-setting) or iCare® TonoVet Plus (dog-setting)], and fluorescein and Rose Bengal stains, was performed. Ocular surface flora culture swabs were collected for microbiology in four salamanders. Rocuronium bromide (50 μL; 0.01 mg) was administered into each eye in three salamanders. Pupil size and constriction ability were evaluated up to 60 min following administration of rocuronium bromide. Distant visual examination and Doppler heart rate were used to monitor for potential adverse effects of rocuronium bromide.

RESULTS

Observed ocular abnormalities included lipid keratopathy/keratitis (19%; 3/16), parasitic ophthalmitis (19%; 3/16), and cataracts (6.3%; 1/16). A significant difference was found between tonometry with iCare® TonoVet (11.5 ± 2.7 mmHg) versus TonoVet Plus (15.4 ± 3.7 mmHg) (p = .025). Fluorescein and Rose Bengal stains were negative in all salamanders. Ocular surface microbiology revealed a high incidence of contamination from environmental flora, with the most common isolate being unidentified as Gram-negative nonfermenters (75%; 3/4). No significant change in pupil size or constriction ability was observed with rocuronium bromide.

CONCLUSION

This is the first study to document ocular examination findings and diagnostics in captive and wild urodeles and may serve as a reference for clinical assessment and future studies of the Western tiger salamander.