Intraocular pressure, ultrasonographic and echobiometric findings of juvenile Yacare caiman (Caiman yacare) eye

Abstract

The aim was to determine the intraocular pressure (IOP), the ultrasonographic and echobiometric findings in the eyes of juvenile Yacare caiman (Caiman yacare). Twenty-two healthy caimans from a breeding farm in Brazilian Pantanal. Intraocular pressure was measured under physical restraint and topical anesthesia by applanation tonometry. Five individual measurements of each eye were recorded by the same examiner. B-mode ultrasonography was performed with a 10-MHz linear transducer, and the anterior chamber depth, lens thickness, vitreous depth, and axial globe length were measured. Unpaired and paired t-tests were used to assess data. Pearson's test was used to assess correlations between IOP and ocular structures (P<0.05). Mean±SD IOP of the 44 eyes studied was 9.56±2.69 mmHg, (range 5.4-15.6mmHg). IOP did not differ significantly between right and left eyes or between genders (P>0.05). Echobiometric measurements did not differ significantly between eyes and genders (P>0.05). Intraocular structures measured in male and female subjects were, respectively, 2.61±0.13 and 2.55±0.18mm for anterior chamber depth, 7.60±0.17 and 7.54±0.20mm for lens thickness, 6.83±0.20 and 6.90±0.22mm for vitreous chamber depth, and 17.55±0.25 and 17.54±0.29mm for axial globe length. Correlations were not observed (P>0.05). Reference values of tonometry and distances of intraocular structures of Yacare caiman were described. IOP did not correlate with echobiometric measurements in this crocodilian. The ultrasonographic appearance was similar to other domestic and wild species.