ABSTRACT OF THE WEEK

Veterinary ophthalmology
Volume 23 | Issue 6 (November 2020)

Congenital ocular malformations in dogs and cats: 123 cases.

Vet Ophthalmol. November 2020;23(6):964-978.

Inês Q Saraiva¹, Esmeralda Delgado²

¹ CIISA - Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal.; ² CIISA - Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal.

Abstract

OBJECTIVE:Provide epidemiological data regarding the prevalence of congenital ocular malformations in dogs and cats.

ANIMALS STUDIED:A population of 32 974 dogs and 13 977 cats that presented for consultation at the veterinary teaching hospital.

PROCEDURES:Medical records from 2011 to 2018 were reviewed. A retrospective and prospective epidemiological clinical study addressing congenital ocular malformations was conducted. Signalment, medical history, reason for presentation, clinical findings, vision impairment, and treatment options were analyzed.

RESULTS:From the total of cases analyzed, 103 dogs (0.3%) and 20 cats (0.1%) met the inclusion criteria. The majority of dogs were mixed breed, the most common breed being the French Bulldog, while the majority of cats were European domestic shorthair. The median age of diagnosis was 12 months for dogs and 6 months for cats. Sex predisposition was not found. The most frequently identified abnormalities were as follows: congenital cataract (dogs: 31.1%; cats: 30.0%), microphthalmia (dogs: 35.0%, cats: 25.0%), and persistent pupillary membrane (dogs: 27.2%, cats: 40.0%). Some of the concurrently observed malformations were significantly associated. A statistically significant association was found between ocular dermoids and the French Bulldog breed (P < .001).

CONCLUSIONS:Even though congenital ocular malformations are uncommon, knowledge about their prevalence is important, since they can cause vision impairment or even blindness. Moreover, some human ocular disease phenotypes are similar to the ones presented by dogs and cats, so they can be used as models to investigate pathophysiology and therapeutic approaches.

Companion Notes

Retrospective and prospective epidemiological clinical study report on congenital ocular malformations in 103 dogs and 20 cats seen at the University of Lisbon

Study design

- study population: animals seen at a veterinary teaching hospital

- 103 out of 32,974 dogs were included

(0.3%; 95% CI: 0.26-0.38%)

- with a total of 164 affected eyes

- 20 out of 13,977 cats were included

(0.1%; 95% CI: 0.02-0.22%)

- with a total of 36 affected eyes

- procedure: records from 01/11-06/18 retrospectively reviewed

Results

- history and signalment in the 103 dogs

- sex:M, 56 cases

- breeds represented by 3 or more cases

- mixed breed, 19 cases

- French bulldog, 16

- golden retriever, 9

- cocker spaniel, 8

- Labrador retriever, 5

- shar pei, 4

- great Dane, 3

- Jack Russel terrier, 3

- shih tzu, 3

- median age at diagnosis: 12 months of age

- with a range of 1 month to 11.8 years

- history and signalment in the 20 cats

- sex:F, 12 cases

- breeds represented by 2 or more cases

- European domestic shorthair, 16 cases

- Persian cat, 2

- median age at diagnosis: 6 months of age

- with a range of 1 month to 11.5 years

- abnormalities identified in the 103 dogs

(61 dogs had bilateral ocular congenital abnormalities)

- congenital cataract, 31.1%

- significant associated with the following:

- microcornea

- microphakia

- microphthalmos

- congenital nystagmus

- ocular dermoid

- microphthalmia, 35%

- persistent pupillary membrane, 27.2%

- congenital nystagmus, 16 cases

- ocular dermoid, 16 cases

- French bulldog breed and ocular dermoids significantly associated

- 12 of the 16 cases were in French bulldogs

- 13 dogs had 1 ocular dermoid

- 2 dogs had 1 ocular dermoid in each eye

- 1 dog had 2 ocular dermoids in one eye

- secondary ocular lesions were found in association with 10 ocular dermoids

- including the following:

- nonpigmentary keratitis, 3

- pigmentary keratitis, 2

- corneal ulcer, 2

- conjunctivitis, 2

- others

- goniodysgenesis, 12 cases

- microphakia, 11

- heterochromia, 6

- microcornea, 5

- microblepharon, 4

- micropapilla, 4

- anophthalmos, 3

- persistent hyaloid artery, 3

- iris hypoplasia, 3

- congenital glaucoma, 2

- lacrimal micropunctum, 2

- lacrimal punctal atresia, 2

- congenital uveal cyst, 2

- congenital entropion, 1

- congenital keratoconjunctivitis sicca, 1

- optic nerve hypoplasia, 1

- posterior lenticonus, 1

- spherophakia, 1

- abnormalities identified in the 20 cats

(16 cats had bilateral malformations)

- congenital cataract, 30.0%

- microphthalmia, 25%

- persistent pupillary membrane, 40%

- persistent pupillary membrane, 8 cases

- heterochromia, 4

- congenital glaucoma, 3

- congenital nystagmus, 3

- microphakia, 3

- palpebral agenesis, 2

- anophthalmos, 1

- congenital uveal cyst, 2

- iris hypoplasia, 1

- bilateral or unilateral abnormalities

- in the dogs

- bilateral abnormalities

- occurred in single cases of the following:

- congenital entropion

- congenital keratoconjunctivitis sicca

- optic nerve hypoplasia

- posterior lenticonus

- spherophakia

- occurred in all cases of nystagmus

- unilateral

- occurred in all cases of congenital glaucomas

- occurred in all cases of congenital uveal cysts

- occurred in all cases of persistent hyaloid artery

- remaining abnormalities were seen unilaterally or bilaterally

- in the cats

- bilateral seen in all cases of the following:

- anophthalmos

- heterochromia

- microphakia

- nystagmus

- palpebral agenesis

- unilateral, single case of iris hypoplasia

- remaining abnormalities were seen unilaterally or bilaterally

- concomitant ocular congenital malformations seen in 3 or more cases

- congenital cataract and microphthalmos, 5 cases

- congenital cataract, microphthalmos, and nystagmus, 3

- congenital cataract, microphthalmos, and PPM, 3

(PPM = persistent pupillary membrane)

- congenital cataract, microphthalmos, nystagmus and PPM, 3

- treatment

- 42 dogs and 9 cats did not need any medication or surgery

- surgery recommended in 52 dogs and performed in 25

- ocular dermoid removal in 12

- cataract phacoemulsification with intraocular lens implantation, 9

- surgery recommended in 10 cats and performed in 4

“In this case series, 36.9% of the dogs and 50% of the cats presented multiple malformations and a maximum of 7 abnormalities was found in one dog.”

Keywords

congenital cataract; congenital ocular malformations; microphthalmia; persistent pupillary membrane;

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