Preoperative findings and visual outcome associated with retinal reattachment surgery in dogs: 217 cases (275 eyes).

OBJECTIVE: Report the correlation of pre-operative findings with visual outcome in dogs undergoing retinal reattachment surgery for giant retinal tears. PROCEDURES: Retrospective analysis of dogs that underwent pars plana vitrectomy (PPV) with silicone oil (SiO) tamponade and endolaser retinopexy at one institution. Recorded parameters included signalment, etiology, and duration of retinal detachment, observable retinal tissue architecture, visual reflexes, lens status, presurgical aqueous flare, visual status postoperatively, and complications. RESULTS: Two hundred and seventeen patients (275 eyes) were included. Common etiologies of detachment were primary vitreoretinal disease (50.5%), lens surgery (35.3%), and hypermature cataracts (6.2%). Immediate postoperative anatomic success was noted in 98% of operated eyes. Maintenance or return of vision was noted in 74.2% of patients (72% of eyes) through the last known follow-up, with return of vision on average 18.5 days postoperatively. In those eyes that regained vision, 71.7% had retained vision at the last known recheck examination, with an average follow-up time of 550 days. Pre-operative findings correlated with postoperative vision included presence of a dazzle reflex, presence of a menace response, and retinal tissue architecture. The most common complications included migration of SiO into the anterior chamber (49.4%), corneal ulceration (25.7%), glaucoma (25.7%), and cataract formation (24.5%). CONCLUSION: Giant retinal tears in dogs can be successfully managed via PPV with SiO tamponade and endolaser retinopexy. Vision was maintained in the majority of cases with long-term follow-up. Patient history and thorough ophthalmic examination with attention to retinal tissue architecture are important in assessing surgical candidacy.

Electroretinogram evaluation of equine eyes with extensive 'bullet-hole' fundic lesions.

OBJECTIVE: To evaluate the impact of extensive bullet-hole nontapetal fundic lesions in horses on retinal function as measured by full-field electroretinography (ERG). MATERIALS AND METHODS: Full-field ERG was performed on two horses with numerous bullet-hole lesions in the nontapetal fundus of both eyes. The ERG was first recorded from the eye with the more extensive lesions in response to a low-intensity light stimulus (0.03 cd s/m(2) ) that was given at times (T) T = 5, 10, 15, 20 min of dark adaptation. Consecutively, combined rod-cone response was evaluated bilaterally in response to high-intensity light stimulus (3 cd s/m(2) ), followed by cone function evaluation by flicker stimulus (3 cd s/m(2) at 30 Hz). Off-line analysis of the ERG recordings was then performed. RESULTS: Despite extensive bullet-hole lesions in the nontapetal fundus bilaterally in both horses, retinal function as measured by ERG did not show any observable deficits. The b-wave amplitude of the full-field ERG increased continuously from 5 to 20 min of dark adaptation peaking at 446 µv and 377 µv for horse number 1 and 2, respectively. The b-wave amplitudes of the combined rod-cone response were OS- 459 µv and OD- 392 µv for horse number 1 and OS- 491 µv and OD- 608 µv for horse number 2. The amplitude of the flicker ERG for horse number 1 was OS- 86 µv and OD- 110 µv and for horse number 2, OS- 80 µv and OD- 74 µv. CONCLUSIONS: Extensive bullet-hole chorioretinal lesions do not appear to compromise outer retinal function in these horses.

Chronic retinal detachment and giant retinal tears in 34 dogs: outcome comparison of no treatment, topical medical therapy, and retinal reattachment after vitrectomy.

The outcomes of dog's eyes with chronic (> 1 month) retinal detachment and giant retinal tears without therapy were compared with those treated with topical steroids and antiglaucoma medications, and with those that received a vitrectomy, retinal reattachment, endolaser therapy, and silicone oil tamponade. Fourteen of 16 eyes that did not receive therapy developed uveitis and secondary glaucoma, and were enucleated (4) or eviscerated (6); and 2 dogs were euthanized due to blindness and uveitis. Two eyes in 2 dogs remain without treatment, 1 and 3 years later. Fifteen of 19 eyes that received topical therapy developed nonresponsive uveitis and secondary glaucoma, and were enucleated (4) or eviscerated (9), 1 dog that was affected bilaterally was euthanized; and 3 eyes remain on topical anti-inflammatory therapy and the medication has been discontinued on 1 eye. Four of 6 eyes surgically reattached remain without clinical manifestations of uveitis and secondary glaucoma and 3 of these eyes have functional vision. Light microscopic observations completed on failed globes in the 3 groups were similar.

Management of giant retinal tears in dogs.

Sixteen dogs with giant retinal tears resulting in total retinal detachment (360 degrees) underwent unilateral retinal reattachment surgery. In all dogs, complete vitrectomy was performed, and in most, perfluorooctane liquid was used to unroll and flatten the detached retina. Stainless steel tacks were used to anchor the retina to the choroid and sclera. Silicone oil was injected into the vitreous cavity to provide for permanent retinal tamponade. Endophotocoagulation or cryosurgery was used in several dogs to induce formation of permanent chorioretinal adhesions. Retinal attachment was successful in 14 of 16 dogs, and 13 of 14 dogs in which reattachment was successful retained some degree of vision. Complications included formation of cataracts and corneal erosions, development of glaucoma, and dislodgement of tacks.

Surgical repair of rhegmatogenous retinal detachments in dogs.

One to five weeks after cataract removal, retinal detachments due to retinal breaks (rhegmatogenous detachments) were detected in 4 dogs. Surgical repair of the detachments, using a scleral buckling procedure, was successful in 3 of the 4 dogs.