Ocular Examinations and Investigation of Intraocular Pressure, Tear Production, Central Corneal Thickness, and Corneal Touch Threshold in a Captive Flock of Atlantic Puffins (Fratercula arctica).

Ocular examinations were completed on a group of 10 Atlantic puffins (Fratercula arctica), 5 males and 5 females that ranged in age from 8 months to older than 30 years. The exams consisted of intraocular pressure/rebound tonometry, tear production/phenol red thread test, central corneal thickness/ultrasound pachymetry, and corneal sensitivity/esthesiometry. On ocular examination, there were no corneal abnormalities observed. Bilateral cataracts were diagnosed in 8 puffins, 6 of which were considered incipient, focal subcapsular opacities. One bird had hypermature cataracts and was removed from the study and excluded from data analysis; the other birds had no evidence of ophthalmic pathology that would interfere with diagnostic results (n = 9). All results for 9 birds were included in the study, with the exception of 1 puffin's tear production, which was too low for accurate assessment and was excluded from data analysis. There were no significant differences between right and left eye measurements for intraocular pressure, corneal thickness, and corneal sensitivity. The median intraocular pressure for both eyes (OU) was 13 mm Hg with an interquartile range [IQR] of 12-15 mm Hg. The median corneal thickness OU was 241 µm, IQR 233-248 µm. The median corneal sensitivity OU was 1.13 cm, IQR 0.81-1.50 cm. There was a significant difference between right and left eye measurements for tear production (right eye median, 7.5 mm/15 s, IQR 6.5-9.3 mm/15 s; and left eye median, 5.0 mm/15 s, IQR 4.0-7.3 mm/15 s) (P= .03), with the right eye producing more tears than the left. However, 1 puffin was determined to be an outlier, and when removed, there was no longer a significant difference (OU median, 7.0 mm/15 s, IQR 4.6-8.0 mm/15 s) (P = .38). There was no significant difference between sex and intraocular pressure, tear production, and corneal sensitivity. However, there was a significant difference between sex and corneal thickness (P = .02), with males (left eye median, 249 µm, IQR 241-249 µm) having thicker corneas than females (left eye median, 236 µm, 234-238 µm). Although sample size precluded statistical testing, there appeared to be an association between opacities and increasing age. There were no associations between age and intraocular pressure, tear production, or corneal thickness. There was a moderate correlation between age and corneal sensitivity, with older birds showing decreased corneal sensitivity (r = -0.57). Although the sample size of 9 birds was small, these findings provide preliminary ranges for ocular parameters of Atlantic puffins.

Surgical outcome of cats treated for aqueous humor misdirection syndrome: a case series.

OBJECTIVE: To evaluate the clinical outcome of cats treated surgically for aqueous humor misdirection syndrome. METHODS: A retrospective analysis of cats treated surgically between January 1, 2006, and January 1, 2013, for aqueous humor misdirection syndrome was performed. Signalment, medical therapy, eyes affected, intraocular pressures prior to and after surgery, surgical procedures performed, postoperative complications, and visual status were evaluated. RESULTS: Seven cats (nine eyes) fit the inclusion criteria. Six of seven cats were female, and five of seven cats were diagnosed with bilateral aqueous humor misdirection syndrome. Three surgical approaches were evaluated as follows: (i) phacoemulsification and posterior capsulotomy, (ii) phacoemulsification, posterior capsulotomy and anterior vitrectomy, and (iii) phacoemulsification, posterior capsulotomy, anterior vitrectomy, and endocyclophotocoagulation. The mean age at diagnosis was 12.9 years. Seven of nine eyes had controlled intraocular pressure (≤25 mmHg) during the first 6 months postoperatively. All cats were visual with controlled intraocular inflammation at 1 year postoperatively; however, one eye had an elevated intraocular pressure. All cats were continued on topical antiglaucoma and anti-inflammatory medications following surgery with the mean number of drops per day decreasing from 3.9 drops/day prior to surgery to 2.2 drops/day postoperatively. CONCLUSIONS: Surgical management for feline aqueous humor misdirection syndrome may be a viable option to maintain a visual and normotensive status in cats that no longer have successful control of intraocular pressure with medical therapy.

Efficacy of prophylactic antiglaucoma and anti-inflammatory medications in canine primary angle-closure glaucoma: a multicenter retrospective study (2004-2012).

PURPOSE: To evaluate long-term efficacy of antiglaucoma medications with or without combined topical anti-inflammatory treatment in preventing increased intraocular pressure and clinical signs of glaucoma in eyes considered at risk of the development of the disease. METHODS: Retrospective analysis identified 88 canine patients presenting with unilateral acute congestive primary angle-closure glaucoma (IOP > 25 mm Hg) and gonioscopic findings of pectinate ligament dysplasia and/or narrow or closed iridocorneal angle in the contralateral nonglaucomatous eye. Patients with histopathologic confirmation of pectinate ligament dysplasia or angle closure in the initial glaucomatous eye receiving prophylactic medical therapy in the contralateral eye were included. Time to medical failure for each antiglaucoma medication and efficacy of the combination therapy were evaluated. RESULTS: The most commonly affected pure-breds were the American Cocker Spaniel (20.4%) and Basset Hound (11.36%). The patients receiving demecarium bromide 0.125% had the longest estimated median time to medical failure at 330.0 days, followed by latanoprost 0.005%, dorzolamide hydrochloride 2.0%, and demecarium bromide 0.25% at 284.0 days, 272.5 days, and 143.0 days, respectively. The estimated median time to medical failure for patients receiving topical antiglaucoma and anti-inflammatory medication was 324.0 days versus 195.0 days in patients receiving antiglaucoma medication alone. Survival analysis showed no statistical significance. CONCLUSIONS: None of the four antiglaucoma medications evaluated statistically delayed medical failure when compared to each other. Although significance was not achieved, our data suggest that adjunctive use of topical anti-inflammatory medications may be beneficial in these cases.

Ocular lesions in canine mucopolysaccharidosis I and response to enzyme replacement therapy.

PURPOSE: Mucopolysaccharidosis I (MPS I) is an inherited metabolic disorder resulting from deficiency of α-L-iduronidase and lysosomal accumulation of glycosaminoglycans (GAG) in multiple tissues. Accumulation of GAG in corneal stromal cells causes corneal opacity and reduced vision. The purpose of this study was to determine the extent of ocular GAG accumulation and investigate the effectiveness of intravenous enzyme replacement therapy (ERT) on corneal GAG accumulation in dogs. METHODS: Ocular tissues were obtained from 58 dogs with mucopolysaccharidosis I and four unaffected controls. Affected dogs received either low-dose ERT, high-dose ERT, or no treatment; some low-dose dogs also received intrathecal treatments. Histologic severity of corneal stromal GAG accumulation was scored. RESULTS: Accumulation of GAG was found in corneal stromal cells and scleral fibroblasts but not in corneal epithelium, endothelium, ciliary epithelium, choroid, retina, retinal pigment epithelium, or optic nerve. Corneal GAG accumulation increased in severity with increasing age. Although low-dose ERT did not significantly reduce corneal stromal GAG accumulation in comparison with untreated animals, high-dose ERT did result in significantly less GAG accumulation compared with the untreated dogs (adjusted P = 0.0143) or the low-dose ERT group (adjusted P = 0.0031). Intrathecal treatments did not significantly affect GAG accumulation. Dogs that began ERT shortly after birth also had significantly less (P < 0.0001) GAG accumulation in the corneal stroma than dogs with a later onset of treatment. CONCLUSIONS: These data suggest that high-dose, intravenous ERT is effective at preventing and/or clearing corneal stromal GAG accumulation, particularly if initiated early after birth.