Canine glaucoma is a group of disorders that are generally associated with increased intraocular pressure (IOP) resulting in a characteristic optic neuropathy. Glaucoma is a leading cause of irreversible vision loss in dogs and may be either primary or secondary. Despite the growing spectrum of medical and surgical therapies, there is no cure, and many affected dogs go blind. Often eyes are enucleated because of painfully high, uncontrollable IOP. While progressive vision loss due to primary glaucoma is considered preventable in some humans, this is mostly not true for dogs. There is an urgent need for more effective, affordable treatment options. Because newly developed glaucoma medications are emerging at a very slow rate and may not be effective in dogs, work toward improving surgical options may be the most rewarding approach in the near term. This Viewpoint Article summarizes the discussions and recommended research strategies of both a Think Tank and a Consortium focused on the development of more effective therapies for canine glaucoma; both were organized and funded by the American College of Veterinary Ophthalmologists Vision for Animals Foundation (ACVO‐VAF). The recommendations consist of (a) better understanding of disease mechanisms, (b) early glaucoma diagnosis and disease staging, (c) optimization of IOP‐lowering medical treatment, (d) new surgical therapies to control IOP, and (e) novel treatment strategies, such as gene and stem cell therapies, neuroprotection, and neuroregeneration. In order to address these needs, increases in research funding specifically focused on canine glaucoma are necessary.

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Aim To examine the use of prophylactic anti‐glaucoma medications in the normotensive fellow eye in dogs with unilateral overt primary glaucoma by veterinary ophthalmology clinicians. Methods A survey of veterinary ophthalmology clinicians was distributed over two international list serves servicing veterinary ophthalmologists, trainees, and individuals whose practice consisted primarily of ophthalmic patients. The survey was developed following analysis of historical and currently available medical options for control of intraocular pressure and for neuroprotection. Results Responses from 199 veterinary ophthalmology clinicians were evaluated. While a large variety of topical anti‐hypertensive drugs and protocols were used, the most commonly used medications were aqueous humor production suppressors such as dorzolamide 2.0% ophthalmic solution, timolol 0.5% ophthalmic solution, and a combination product containing both drugs. Latanoprost 0.005% ophthalmic solution was used infrequently for prophylaxis by comparison. The majority of respondents do not use concurrent anti‐inflammatory medications (61.22%), although a sizeable minority used prednisolone acetate, dexamethasone, or ketorolac as prophylactic treatment. Systemically administered ocular anti‐hypertensive agents were rarely used. Only 40% of respondents used neuroprotectant agents; the most commonly prescribed were the calcium channel blocker amlodipine and the nutraceutical Ocu‐Glo™. Recommended intervals between re‐examination by the clinician ranged from one month to one year, with most re‐evaluations occurring every 3 to 6 months. The majority of respondents recommended more frequent assessments of IOP at intervals between once monthly and once every 3 months. Conclusions Data analysis of medical therapy for the normotensive fellow eye of dogs previously diagnosed with primary glaucoma suggests that there is a great need for well‐designed, prospective, controlled, multi‐center studies to determine which protocols have the greatest efficacy in delaying an overt attack in the previously normotensive eye in dogs with a genetic predisposition to glaucoma. Prospective studies utilizing a carbonic anhydrase inhibitor such as dorzolamide and a prostaglandin analogue such as latanoprost would be reasonable as these two drugs are widely used in the treatment of overt glaucoma and would allow for an exploration of the impact of different mechanisms of action of lowering IOP on the pathophysiology of primary glaucoma.

Objective To determine whether topical administration of the aldose reductase inhibitor KinostatÔ can ameliorate the onset or progression of cataracts in dogs with naturally occurring diabetes mellitus (DM). Materials and Methods A randomized, prospective, double-masked placebo control pilot study was conducted with 40 dogs newly diagnosed with DM with no or minimal lens changes. Twenty-eight dogs received KinostatÔ and 12 dogs received placebo. Procedures Owners administered the agent into both eyes three times daily for 1 year and compliance was monitored with log sheets. Complete ophthalmic examinations were performed on dilated eyes at the time of enrollment and 1, 2, 3, 6, and 12 months into treatment. Cataract severity was assessed on a scale of 0-3. At 12 months, full bloodwork, including HbA1C and blood Kinostat TM levels were performed.Results After 12 months of treatment, the cataract score in the placebo group significantly increased with seven dogs (14 eyes) developing mature cataracts, two dogs (4 eyes) developing cortical opacities, and one dog (2 eyes) developing equatorial vacuoles with mild punctate cortical opacities. In contrast, the cataract score in the Kinostat TM treated dogs was significantly less with seven developing anterior equatorial vacuoles, two developing incipient anterior cortical cataracts, and four developing mature cataracts. In fact, the cataract scores of the Kinostat TM group at 12 months did not significantly increase from the score at the time of enrollment. The HbA1C values between the two groups after 12 months of treatment were similar, and no blood levels of Kinostat TM were found in any enrolled dog.Conclusion The onset and/or progression of cataracts in dogs with DM can be significantly delayed by topical administration of KinostatÔ.

A unique eye color, called tiger-eye, segregates in the Puerto Rican Paso Fino (PRPF) horse breed and is characterized by a bright yellow, amber, or orange iris. Pedigree analysis identified a simple autosomal recessive mode of inheritance for this trait. A genome-wide association study (GWAS) with 24 individuals identified a locus on ECA 1 reaching genome-wide significance (Pcorrected = 1.32 × 10−5). This ECA1 locus harbors the candidate gene, Solute Carrier Family 24 (Sodium/Potassium/Calcium Exchanger), Member 5 (SLC24A5), with known roles in pigmentation in humans, mice, and zebrafish. Humans with compound heterozygous mutations in SLC24A5 have oculocutaneous albinism (OCA) type 6 (OCA6), which is characterized by dilute skin, hair, and eye pigmentation, as well as ocular anomalies. Twenty tiger-eye horses were homozygous for a nonsynonymous mutation in exon 2 (p.Phe91Tyr) of SLC24A5 (called here Tiger-eye 1), which is predicted to be deleterious to protein function. Additionally, eight of the remaining 12 tiger-eye horses heterozygous for the p.Phe91Tyr variant were also heterozygous for a 628 bp deletion encompassing all of exon 7 of SLC24A5 (c.875-340_1081+82del), which we will call here the Tiger-eye 2 allele. None of the 122 brown-eyed horses were homozygous for either tiger-eye-associated allele or were compound heterozygotes. Further, neither variant was detected in 196 horses from four related breeds not known to have the tiger-eye phenotype. Here, we propose that two mutations in SLC24A5 affect iris pigmentation in tiger-eye PRPF horses. Further, unlike OCA6 in humans, the Tiger-eye 1 mutation in its homozygous state or as a compound heterozygote (Tiger-eye 1/Tiger-eye 2) does not appear to cause ocular anomalies or a change in coat color in the PRPF horse.

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Objective: To present a novel case of perinatal bilateral exophthalmos and corneal ulcers in a neonate Antillean manatee and describe the medical treatment that led to the resolution of the observed clinical signs and vision restoration.

Diabetic dogs rapidly form bilateral sugar cataracts within one year of diagnosis. Similar sugar cataracts also form in galactose‐fed dogs. Since topical KinostatTM has been shown to reverse initial cataract formation in young galactose‐fed dogs, we have conducted a proof of concept masked pilot study with 41 newly diagnosed dogs with diabetes mellitus (DM) to investigate whether KinostatTM can inhibit the progression of cataracts in a clinical setting. After obtaining owner consent to participate in the study, all dogs were randomly assigned a coded vial containing either KinostatTM or vehicle for 1 year with the contents of the vial (drug or placebo) masked from the examiners. Thirty dogs received the active agent while the remainder received the placebo vehicle. Owners were instructed to administer the agent 3 times daily to both eyes and compliance was monitored by recording each time of administration. Ocular examinations on dilated eyes conducted at the initial examination and at 1, 2, 3, 6, and 9 month intervals with slit lamp and indirect ophthalmoscopy indicated that KinostatTM is beneficial in arresting the onset and/or progression of cataracts in dogs with DM. The implications of this study for human sugar cataracts will also be discussed. Supported by NIH SBIR 1R43EY018013‐01A1 Commercial interest