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

Frequency of retinal detachments in dogs after prophylactic transpupillary retinopexy

PURPOSE

To evaluate the frequency of retinal detachments following prophylactic transpupillary retinopexy (PTPRP).

METHODS

The medical records of dogs that received a PTPRP between 2014 and 2022 were retrospectively analyzed for age, sex, breed, reason for retinopexy, laser power setting, number of retinal burns, follow-up duration, and outcome. Laser power settings were increased until retinal burns could be visualized and were made 360° in a double row in the peripheral retina.

RESULTS

Fifty-seven cases (75 eyes), 28 males and 29 females, had PTPRP performed. The median age was 8 years (4 months-14 years) with Shih tzu (n = 12), Bichon (n = 5), Miniature Poodle (n = 5), and Yorkie (n = 4) being the most common breeds. PTPRP were performed due to severe vitreal degeneration (n = 66), retinal detachment in the contralateral eye (n = 25), capsular tear with escaped lens material during phacoemulsification (n = 6), intracapsular lens extraction (n = 2), and lens luxation during phacoemulsification (n = 3). The median power setting, number of retinal burns, and follow-up time were 300 mW (201-595 mW), 210 burns (35-921 burns), and 473 days (14-1862 days), respectively. Additionally, five patients had a barrier-pexy performed in the contralateral eye, due to partial detachment. Retinal detachment occurred in 3/75 (4.0%) of eyes that received a PTPRP at the final examination. Of the patients with a detachment in the contralateral eye (n = 25), no detachment was noted at the last follow-up examination. Two partial detachments that had barrier-pexies had progressed at the final examination.

CONCLUSIONS

These results demonstrate that PTPRP may be beneficial in decreasing the risk of retinal detachment in selected cases.

Optic nerve colobomas associated with unilateral focal serous retinal detachment in a dog - In-vivo imaging and outcome following laser retinopexy

PURPOSE

To describe the ophthalmoscopic, in-vivo imaging, fluorescein angiography, and therapeutic photocoagulation outcome in a case of bilateral optic nerve colobomas associated with focal unilateral retinal detachment in a dog.

METHODS

Pretraining eye examination of a 1.6-year-old female German shepherd service dog showed a focal juxta-papillary bullous retinal separation in the right eye. In vivo imaging and angiography were performed under general anesthesia using optical coherence tomography. Nonoverlapping diode laser burns were applied through an operating microscope adapter to selected areas along the leading margins of the detachment.

RESULTS

The funduscopic examination and in-vivo imaging revealed bilateral optic nerve colobomas associated with a focal bullous detachment in the right eye. Fluorescein angiography showed absence of blood vessel leakage and absence of staining inside of the retinal elevation. Photocoagulation induced immediate changes in retinal layer reflectivity. Three months post-photocoagulation, the retinal detachment had improved and scarring of the burns was visible. One and two years post-procedure, the retinal detachment resolved.

CONCLUSIONS

Optical coherence tomography (OCT) imaging provides a detailed analysis of the retinal abnormalities associated with the clinical lesion. Laser retinopexy is a valid therapeutic option to limit the extension of the detachment.

Outcome of 25-gauge pars plana vitrectomy via a lateral approach without proptosis of the globe: A retrospective study in 72 dogs (78 eyes)

OBJECTIVE

To evaluate the postoperative visual outcome and complications of 25-gauge pars plana vitrectomy (PPV) via a lateral approach without proptosis of the globe in dogs.

PROCEDURES

We reviewed the medical records of dogs diagnosed with giant rhegmatogenous retinal detachment (RRD) at Yokohama Animal Eye Clinic from 2016 to 2019 and treated by 25-gauge PPV. Medical records included signalment, follow-up time, etiology and duration of RRD, angle between the outermost trocar ports, immediate postoperative anatomic success rate, pre- and postoperative visual status, and postoperative complications.

RESULTS

Seventy-two dogs (78 eyes, 13 breeds) were included. The most common breed was the Toy Poodle (48.6%), and the mean follow-up time was 690.6 days. The most common etiology of RRD was cataract surgery (46.2%). The mean angle between the outermost trocar ports was 71.4º. Immediate postoperative anatomic success was noted in all eyes. Vision was regained or maintained in 87.2% of eyes, and the mean time to return of vision was 28.5 days. Maintenance of vision until the last known follow-up was noted in 73.5% of eyes. The most common postoperative complication was glaucoma (40.3%), and glaucoma was the most common etiology of postoperative vision loss (88.9%).

CONCLUSION

Twenty-five gauge PPV via a lateral approach without proptosis of the globe is a successful method for treating canine giant RRD.

Presumed neuroprotective therapies prescribed by veterinary ophthalmologists for canine degenerative retinal and optic nerve diseases

OBJECTIVE

To investigate veterinary ophthalmologists' use of presumed neuroprotective therapies for degenerative retinal and optic nerve diseases in dogs.

PROCEDURES

An online survey was sent to 663 board-certified veterinary ophthalmologists who were Diplomates of the American College of Veterinary Ophthalmologists (ACVO), Asian College of Veterinary Ophthalmologists (AiCVO), Latin American College of Veterinary Ophthalmologists (Colegio Latinoamericano de Oftalmólogos Veterinarios, CLOVE), or European College of Veterinary Ophthalmologists (ECVO). The survey was created using Qualtrics® software and focused on the prescription of presumed neuroprotective treatments for canine glaucoma, sudden acquired retinal degeneration syndrome (SARDS), progressive retinal atrophy (PRA), and retinal detachment (RD).

RESULTS

A total of 165 completed surveys were received, representing an overall response rate of 25%, which was comparable across the four specialty colleges. Of all respondents, 140/165 (85%) prescribed some form of presumed neuroprotective therapies at least once in the last five years: 114/165 (69%) for glaucoma, 51/165 (31%) for SARDS, 116/165 (70%) for PRA, and 50/165 (30%) for RD. The three most recommended neuroprotective reagents were the commercial Ocu-GLO™ Vision Supplement for animals, amlodipine, and human eye supplements.

CONCLUSIONS

Despite lack of published clinical efficacy data, the majority of surveyed board-certified veterinary ophthalmologists previously prescribed a presumed neuroprotective therapy at least once in the last five years in dogs with degenerative retinal and optic nerve diseases.

Intraoperative findings and postoperative results associated with cataract surgery performed after retinal reattachment surgery in dogs-36 cases (41 eyes)

OBJECTIVE

To report intraoperative findings and complications associated with cataract surgery performed after retinal reattachment surgery (RR) via pars plana vitrectomy (PPV) using perfluoro-n-octane (PFO), laser retinopexy, and silicone oil tamponade in dogs.

ANIMALS STUDIED

Retrospective record review of dogs that underwent post-RR cataract surgery. Signalment, time between RR and cataract surgery, type of lens extraction, postoperative visual status, and intra- and postoperative complications were recorded. Cataract formation or progression after RR was categorized as early (≤12 months) or late (>12 months).

RESULTS

A total of 36 dogs (41 eyes) were included. Average time between RR and cataract surgery was 665 days (median: 546). Early postoperative incidence of cataracts occurred in 19 eyes (46.3%). Types of lens extraction included phacoemulsification with intraocular lens (86.1%, 31/36 dogs), phacoemulsification alone (11.1%, 4/36 dogs), and intracapsular lens extraction (2.8%, 1/36 dogs). Visual improvement occurred in 95.1% of eyes (39/41) immediately postoperatively. Long term, 93.9% of eyes (31/33) maintained vision at 1 month, 85.2% of eyes (23/27) at 3 months, 77.3% of eyes (17/22) at 6 months, and 60% (12/20) at 12 months postoperatively. The most common postoperative complications were glaucoma (29.3%, 12/41 eyes), corneal ulceration (24.4%, 10/36 eyes), fibrin formation (21.9%, 9/41 eyes), and silicone oil migration into the anterior chamber (19.5%, 8/41 eyes).

CONCLUSION

Post-RR cataract surgery should be considered in dogs with vision loss from cataracts after RR. In most eyes, vision was maintained up to 1 year postoperatively.

Phacoemulsification combined with transpupillary removal of silicone oil and intracapsular intraocular lens implantation

AIM

To estimate the effectiveness of phacoemulsification and foldable intraocular lens (IOL) implantation combined with transpupillary silicone oil removal.

METHODS

There were 168 eyes of 168 candidate patients with cataract and silicone oil-filled eyes recruited in our study. All of the patients received the intraocular silicone oil removal surgery by transpupillary drainage and cataract extraction by phacoemulsification. Then the IOL implantation were also performed through corneal incision.

RESULTS

The surgery was successfully completed in all eyes. Best corrected visual acuity (BCVA) and postoperative complications were recorded in three months after surgery. There were 143 eyes with BCVA improved, otherwise 25 eyes remained stable at the last follow-up visit. The mean BCVA statistically improved from 20/400±0.02 to 20/100±0.15 (P<0.001) and mean postoperative IOP was 13.85±2.18 mm Hg (P=0.415). No intra-operative complications were reported.

CONCLUSION

Phacoemulsification combined with transpupillary removal of silicone oil is a safe and simple effective method. In general, it enables quick recovery of visual acuity with less complication rate.

Subretinal implantation of Okayama University-type retinal prosthesis (OURePTM) in canine eyes by vitrectomy

Okayama University-type retinal prosthesis (OUReP^TM) is a photoelectric dye-coupled polyethylene film which generates electric potential in response to light and stimulates nearby neurons. This study aims to test surgical feasibility of subretinal implantation and functional durability of dye-coupled films in the subretinal space. The dye-coupled films were implanted subretinally by 25-gauge vitrectomy in the right eye of 11 normal beagle dogs: 2 dogs served for film removal after 5-month film implantation, 3 dogs for film removal after 3-month film implantation, 3 dogs for 3-month film implantation and pathological examination, and 3 dogs for sham surgery. The surface electric potential of the removed dye-coupled films in response to light was measured by the Kelvin Probe system. At surgery, rolled-up dye-coupled films in 5 × 5 mm square size could be inserted into subretinal space of retinal detachment induced by fluid injection with a 38-gauge polyimide tip. Retinal attachment was maintained by silicone oil injection in vitreous cavity. At autopsy, the retina in all dogs maintained the ganglion cell layer, inner and outer nuclear layers while it lost the outer segments in some part. All 5 sheets of removed dye-coupled films maintained the dye color. One sheet of the 5-month implanted film showed proportional increase of surface potential in response to increasing light intensity. Subretinal implantation of OUReP^TM by vitrectomy was technically feasible in canine eyes, and OUReP^TM maintained the function of generating light-evoked surface potential after 5 months in subretinal implantation.