A Retrospective study on the association between vitreous degeneration and cataract in dogs.

Objective: This study was performed to evaluate the relationship between cataract and vitreous degeneration on ultrasonography (VDU) in dogs.

Materials And Methods: Medical records of dogs were retrospectively reviewed. The dogs presented at the Veterinary Medical Teaching Hospital of Seoul National University from January 2009 to December 2011 for ocular ultrasonography to investigate the suitability of the patient for cataract surgery. A total of 97 dogs (179 eyes) were included in this study. Data collected included age, gender, ophthalmic examination, and ultrasonographic examination. Cataract was classified into five grades by ophthalmic examination (0: normal, 1: incipient, 2: immature, 3: mature, and 4: hypermature). VDU was classified into 4 grades (0: no degeneration, 1: mild vitreous degeneration, 2: moderate vitreous degeneration, and 3: marked vitreous degeneration).

Results: The mean rank of VDU grades increased with the progression of cataracts, and statistical significant differences were shown between cataracts grade 0 and 2 (P = 0.010), between 0 and 3 (P < 0.001), between 0 and 4 (P = 0.010), between 1 and 3 (P = 0.03), between 1 and 4 (P = 0.02), and between 2 and 4 (P = 0.04). There were no significant differences in age and gender according to the cataract grades. There was no statistical significant difference in the mean rank of VDU grades between cataractous eyes with lens-induced uveitis (LIU) and those without LIU.

Conclusions: The results indicated that increased VDU was associated with more severe cataract grades in dogs.