Editors note: Due to similar anatomical structures in canines and humans, combined efforts and shared information between these two different disciplines can benefit all species. Thus, Review of Optometry has decided to publish a case report about a canine.
Banjo, a 13-year-old terrier canine mix with cataracts in both eyes, underwent bilateral cataract extraction. His left eye developed endophthalmitis within 24 hours after surgery and IOL implantation. The surgeon then performed evisceration and implanted an intraocular prosthesis in his left eye. The lens capsule in Banjos right eye was likely too fragile to sustain an IOL, and his owner did not want an intrasulcus IOL implanted. So, the eye remained aphakic.
Banjos medical history was significant for seizures, which were controlled with 15mg phenobarbital p.o. q.d. His family medical history was unknown.
We estimated Banjos visual acuity to be hand motion in his aphakic right eye, and his left eye was prosthetic. The greenish hue retinoscopy reflex had a slight scissoring motion. Subjective refraction was unachievable, but we estimated optical power to be +19.00D.
Biomicroscopy through a hand-held slit-lamp revealed clean lids and lashes, which were present only on the superior lid; there was no entropion or ectropion.
The inferior palpebral conjunctiva in each eye was pink and smooth. No follicles or papillae were present in either eye. We did not evaluate upper palpebral conjunctivae due to Banjos intractable behavior. The nictitating membrane, the cartilaginous extension of the bulbar conjunctiva, also had no follicles or papillae in either eye.
Banjos left cornea was opacified with neovascularization. His right eye had a clear cornea and a deep and quiet anterior with no cells or flare. A menace response, indicated by a reaction or growl to adverse stimuli, was present in his right eye.
Intraocular pressure was 9mm Hg in his right eye. (Normal canine IOPs range from 15mm Hg to 25mm Hg.)
No significant findings were apparent on the retina or choroid in his right eye after a non-dilated funduscopic examination.
Banjo was diagnosed with aphakia in his right eye and prosthesis in his left eye.
We made distance aspheric +19.00D lenticulated polycarbon-ate lenses and inserted them into Doggles, which are plano sunglass frames/goggles for dogs. His guardian preferred to have aphakic lenses made for both eyes for cosmetic reasons. A plano over-refraction was observed via retinoscopy.
Banjo ran through a small obstacle course both with and without his glasses on the day he received them. Without the glasses, Banjo bumped into the walls and walked with trepidation in areas with large objects. While wearing the glasses, he walked with more confidence. He still hit walls of the maze, as he may have had depth perception problems secondary to the magnification in his new glasses, but he did so less frequently.
|Banjo wearing his Doggles.|
We made a second pair of spectacles that were slight-ly myopic (+20.00D) to improve Banjos motility and vision indoors. We considered bifocal or progressive glasses, but they were too expensive and difficult to create for Banjos purposes.
Cataract extraction and IOL implantation in canines has improved markedly in the past decade.1 However, complications still occur.2,3 One study reported a 79% success rate in restoring functional vision to dogs for at least six weeks postoperatively.4 Endophthlamitis is a rare complication. In this case, it necessitated a scleral prosthesis in Banjos left eye.
Treatment options for his aphakic right eye included:
IOL implant. An IOL would have been the most ideal way to provide Banjo with adequate vision. Because the lens capsule was fragile, however, the veterinary ophthalmologist felt that an IOL was not a viable option. The ophthalmologist also did not want to risk another case of endophthalmitis.
Aphakic contact lenses. This option can provide dogs with good vision without inducing the magnification and distortion that can occur with spectacle use.5 However, the owner must insert, remove and clean the contact lenses daily, and frequent office visits are necessary. Banjos guardian rejected this option because of the potential inconvenience.
No treatment. Leaving Banjo aphakic without any refractive correction would decrease his potential quality of life. This, too, was not a satisfactory option for Banjos guardian.
Aphakic spectacles. Aspheric lenticulated aphakic polycarbonate spectacles were the most viable option for Banjo. Aspheric spectacles would improve Banjos ambulatory vision, thus improving his quality of life. The spectacles could also serve as safety glasses to protect his prosthetic eye.
Disadvantages of spectacles include induced magnification, distortion and the weight of the high prescription. Also, it might be difficult to keep spectacles on Banjos face. However, Banjos guardian, the veterinary ophthalmologist and I decided that the advantages of spectacles outweighed the disadvantages. We ordered aphakic lenses for both eyes to improve Banjos cosmetic appearance.
No literature describing aphakic spectacle correction for monocular canines currently exists. This case report shows a successful spectacle-fitting on a canine through the efforts of Banjos owner and co-management with his veterinary ophthalmologist and optometrist. Human and canine eye care professionals should share visual discoveries so all species can experience the potential benefits.
Dr. Yeung is the director of optometry at the Arthur Ashe Student Health Center at the University of California, Los Angeles. Dr. Silverman is a veterinary ophthalmologist in private practice in Sherman Oaks, Calif.
1. Williams DL, Boydell IP, Long RD. Current concepts in the management of canine cataract: a survey of techniques used by surgeons in Britain, Europe, and the USA and a review of recent literature. Vet Rec 1996 Apr 13;138(15):347-53.
2. Davidson MG, Nasisse MP, Rusnak IM, et al. Success rates of unilateral vs. bilateral cataract extraction in dogs. Vet Surg 1990 May-Jun;19(3):232-6.
3. Biros DJ, Gelatt KN, Brooks DE, et al. Development of glaucoma after cataract surgery in dogs: 220 cases (1987-1998). J AM Vet Med Assoc 2000 Jun 1;216(11):1780-6.
4. Rooks RL, Brightman AH, Musselman EE, et al. Extracapsular cataract extraction: an analysis of 240 operations in dogs. J Am Vet Med Assoc 1985 Nov 15;187(10):1013-5.
5. Yeung KK, Silverman BS, Kageyama JY. Aphakic hydrogel contact lens fitting on a monocular canine: a case report. Optometry 2001 Jul;72(7):421-5.