Evaluation of Selected Ophthalmic Diagnostic Tests in Green Iguanas (Iguana iguana)

The objective of this study was to establish reference parameters for different ophthalmic diagnostic tests in green iguanas (Iguana iguana). Median ± semi-interquartile range values of phenol red thread tear test, endodontic absorbent paper point tear test, Schirmer tear test, palpebral fissure length, and intraocular pressure were 3.9 ± 1.7 mm/15 seconds, 8.5 ± 2.4 mm/minutes, 1.0 ± 0.5 mm/minutes, 12.4 ± 1.7 mm, and 18.0 ± 1.7 mm Hg, respectively. Bacterial growth was observed in 18 of 20 conjunctival samples, with a predominance of Gram-positive bacteria (75.8%). Staphylococcus spp. was the most frequently isolated microorganism (39.4%), and a resistance pattern to polymyxin B was demonstrated through antimicrobial susceptibility testing of the bacterial isolates. Median ± semi-interquartile range anterior chamber depth was 1.2 ± 0.2 mm and 1.4 ± 0.2 mm; vitreous chamber depth, 6.8 ± 0.6 mm and 6.8 ± 0.5 mm; lens length, 4.4 ± 0.3 mm and 4.3 ± 0.3 mm; and axial globe length, 12.6 ± 0.8 mm and 12.5 ± 0.7 mm for the sagittal and dorsal planes, respectively. Conus papillaris length was 6.0 ± 0.3 mm and 5.9 ± 0.5 mm, whereas the conus papillaris width was measured at 1.1 ± 0.2 mm and 1.2 ± 0.2 mm, with no difference between the 4.5- and 7.5-hour planes. Hypercellular samples with dense clusters of basaloid and squamous epithelial cells were observed in the conjunctival cytological samples. These results may be helpful for diagnosis and treatment of ocular disorders in green iguanas.