Ocular dermoids in 13 cats: a multicentre retrospective study

OBJECTIVES

The aim of this multicentre retrospective study was to review the clinical data, outcomes and histopathological features of cats that had been treated for ocular surface dermoids.

METHODS

Thirteen cats from various private practices in France with a clinical diagnosis of ocular surface dermoid were included in the study.

RESULTS

The mean age of the study population at the time of diagnosis was 5 months. There were nine males and four females. Three different breeds were domestic shorthair (n = 7), Birman (n = 4) and Havana Brown (n = 2). Two of the four Birmans were related (same sire). The two Havana Browns were also related (same sire). All of the dermoids were unilateral. Five of the dermoids were strictly conjunctival. Four affected both the conjunctiva and the cornea. Three affected both the conjunctiva and the eyelid, and one was strictly corneal. They were located in various positions: temporal (n = 9), inferonasal (n = 1), dorsonasal (n = 1) and dorsotemporal (n = 1). The last dermoid was heterogeneous and involved the nasal, dorsal and temporal quadrants. Concurrent eye diseases were observed in five patients: four cats exhibited associated eyelid agenesis and one cat exhibited persistent iris-to-iris pupillary membranes. Ten dermoids were surgically excised with no recurrences. Surgery was not performed for three cats: one cat died a few days after diagnosis and two cats were lost to follow-up after initial presentation.

CONCLUSIONS AND RELEVANCE

Ocular surface dermoids are a rare condition in cats that can be treated successfully by surgical excision. Although our study reports only a small number of cases, the observation of ocular surface dermoids in two related cats in two different breeds indicates that genetic transmission is likely.

Recording of the full-field electroretinogram in minipigs

PURPOSE

To test a simple electroretinographic protocol on a representative sample of minipigs.

ANIMAL STUDIED

Minipig.

PROCEDURES

Electroretinogram recordings were conducted on 162 healthy minipigs (81 males and 81 females) aged 4-6 months. After a 1.5-h light-adaptation period, the animals were anesthetized with general anesthesia. First, binocular full-field photopic electroretinogram recordings were conducted under photopic conditions. Subsequently, scotopic electroretinogram recordings were conducted during dark-adaptation periods every 4 min for a 20-min period. At the end of this period, the maximal combined rod-cone response was recorded by measuring the retinal response to a single high-intensity flash. We used sclerocorneal clip electrodes as active electrodes and needle electrodes as reference and ground electrodes.

RESULTS

The a-wave and b-wave peak times and amplitudes have been measured and statistically analyzed. For each of the statistical comparisons, normality and homogeneity of variances were evaluated. No significant gender differences were observed, with the exception of a higher b-wave amplitude for the photopic ERG recordings observed in females when compared to males (48.14 ± 12.909 μV vs. 42.88 ± 10.666 μV; P = 0.005). The process of dark adaptation was evaluated, and the maximal combined rod-cone response was measured (a- and b-waves amplitude and peak time).

CONCLUSIONS

We conducted photopic and scotopic electroretinogram recordings from a protocol based on light adaptation followed by dark adaptation using sclerocorneal clip electrodes, which allows quick assembly and examination.