Progressive retrocorneal pigmentation in dogs: A clinical report of 34 cases.

OBJECTIVES: To describe the signalment, ophthalmic examination findings, and follow-up of dogs affected with a previously unreported retrocorneal pigmentary lesion. MATERIALS AND METHODS: Retrospective record evaluation spanning 2009-2019. RESULTS: Retrocorneal pigmentary lesions were described in 34 patients (46 eyes). German Shepherds (n = 7), Jack Russel terriers (n = 5), and terrier crosses (n = 4) made up 16/34 (47.1%) of the cases. The mean age was 13.5 years (range 1.4-14.2 years), and 16/30 (53.3%) dogs were female. Most dogs were affected unilaterally (22/34 (64.7%)), the others bilaterally, and 5/34 (14.7%) were referred for it while the others were incidentally diagnosed. The lesions affected the ventral, peripheral, inner cornea and had a round/undulated leading edge. The number of corneal clock hours affected was known for 41/46 (89.1%) eyes and involved 1-3 clock hours in 32/41 (78.1%) eyes, 4-6 in 6/41 (14.6%), 7-9 in 2/41 (4.9%), and 10 in 1/41 (2.4%). The central cornea was affected in 9/46 (19.6%) eyes, and in 5/9 (55.6%), the median corneal clarity score was G2 (scale: G0-G4). The commonest additional findings included free-floating uveal cysts (11/34 dogs, 32.4%), cataracts (6/34 dogs, 17.6%), and primary glaucoma (5/34 dogs, 14.7%). Gonioscopy was available in 16/34 (47.1%) dogs and was normal except in primary glaucoma cases. Follow-up was documented in 13/34 (38.2%) dogs with a mean follow-up of 17 months (range: 5-26 months). Lesion progression was documented in 6/13 (46.2%) dogs. CONCLUSIONS: Retrocorneal pigmentation occurs as a slowly progressive lesion of older dogs that could impact vision. Histological studies of affected eyes are warranted.

Light scattering measurements in electron-beam sterilized corneas stored in recombinant human serum albumin.

Irradiated corneal tissues have been used for a variety of ophthalmic procedures including glaucoma drainage device covers and lamellar grafts. The maintenance of corneal clarity is important, as light obstructions resulting from processing or long-term storage of irradiated corneas may negatively affect vision and postoperative cosmesis. It has been reported that corneal tissues can be preserved in human serum albumin (HSA), however, the clarity of corneas after long-term storage in HSA has not been well described. Furthermore, the use of donor-pooled serum increases the risk for transmission of blood-borne diseases and may induce an immune response in the recipient. Here, we examined changes in corneal clarity due to electron-beam (e-beam) irradiation and storage in a recombinant human serum albumin (rHSA). Dark-field microscopy was employed to examine the light scattering effects of fresh and irradiated corneas. Compared to measurements taken prior to tissue preparation and e-beam treatment, irradiated corneas showed an average 2.6% increase in light scattering (P = 0.002). Irradiated corneas stored in rHSA at room-temperature for 20 months showed an average increase of 11.6% light scattering compared to fresh corneas (P â‰ª 0.01), but did not negatively affect the visualization of printed text, and were deemed suitable for transplant use. Therefore, the slight increase in cornea light scattering, and resulting reduction in corneal clarity, after e-beam treatment and long-term storage in rHSA may not be clinically significant. These results suggest that e-beam sterilized corneal grafts may be used as an alternative to fresh tissue for certain ophthalmic applications.

Preliminary results of a prospective study of inter- and intra-user variability of the Royal Veterinary College corneal clarity score (RVC-CCS) for use in veterinary practice.

OBJECTIVE: To introduce a new corneal clarity score for use in small animals and describe its inter- and intra-user variability. ANIMALS STUDIED: Twelve dogs and two cats with corneal abnormalities and five dogs with healthy corneas. MATERIALS AND METHODS: Four examiners scored every patient twice and never consecutively, focusing on the central cornea. The peripheral cornea was scored separately. The following scoring system was used to describe corneal clarity: G0: no fundus reflection is visible on retroillumination (RI) using a head-mounted indirect ophthalmoscope. G1: a fundus reflection is visible with RI. G2: a 0.1-mm diameter light beam is visible on the anterior surface of the iris and/or lens. G3: gross fundic features are visible when viewed with indirect ophthalmoscopy (IO) using a head-mounted indirect ophthalmoscope and a hand-held 30D lens, although fine details are not clear. G4: fine details of the fundic features are clearly visible with IO. The minimum grades given were analyzed for inter- and intra-user variability with kappa analysis. RESULTS: Intra- and interuser variability of the central corneal clarity ranged from 0.78 to 0.96, showing substantial to almost perfect reproducibility, and from 0.66 to 0.91, showing substantial to almost perfect reliability, respectively. Intra- and interuser variability of the peripheral cornea ranged from 0.83 to 0.95, showing almost perfect agreement, and from 0.53 to 0.91, showing moderate to almost perfect agreement. CONCLUSIONS: The RVC-CCS is well suited to assess and monitor central corneal clarity in small animals and to compare outcomes between studies and different surgeons.

The Surgical Outcomes of Simple Keratectomy for Limbal Dermoids

PURPOSE: To evaluate the results of simple keratectomy for limbal dermoids. METHODS: We reviewed the ocular records of 29 consecutive patients with limbal dermoids who had undergone simple keratectomy in Seoul National University Children's hospital from 1989 to 2006. The preoperative and postoperative visual acuity and astigmatism levels as well as the cosmetic outcomes were measured. RESULTS: The mean age at surgery was 28 months (range, 6~70 months), and the mean follow-up period was 56 months (range, 18~168 months). The mean visual acuity at the last follow-up was 20/30. The mean preoperative and postoperative cylinder was -2.64D and -2.12D, respectively, in the affected eye (p=0.064); and -0.79D and -0.43D, respectively, in the fellow eye (p=0.149). There was a significant correlation between preoperative astigmatism and the final visual acuity in the involved eye. No opaque lesions were visible at a distance of 1 meter in 16 of the 29 eyes (55.2%), and there were no significant complications related to the surgery. CONCLUSIONS: Simple keratectomy of limbal dermoids can be a good surgical technique to get a cosmetically acceptable corneal clarity without complication.

Combined Keratoplasty and Cataract Surgery

We evaluated the clinical results of the combined keratoplasty and cataract surgery. Fifty nine patients were devided into 3 groups according to the operation type: Group I; penetrating keratoplasty, cataract extraction and intraocular lens implantation (triple procedure), Group II; penetrating keratoplasty and cataract extraction, Group III; penetrating keratoplasty and intraocular lens implantation. The most common cause of corneal opacity was infection in group I and II, and aphakic bullous keratopathy in group III. The preoperative best corrected visual acuity was less than 20/200 in almost all patients. The postoperative corrected visual acuity of 20/100 or better was obtained in 70%(14 eyes), 53%(9 eyes) and 33.3%(5 eyes) in group I, II and III and 12 months. Clarity of the graft cornea was maintained 90.9% in group I, 55% in group, and 64.7% in group III. The two most common complication were graft rejection and glaucoma. From above results, combined keratoplasty and cataract surgery could be an available procedure which obtain a good visual outcome in patients who have both corneal opacity and cataract. Especially, the triple procedure offers patients the chance of an early visual rehabilitation after graft and cataract surgery with a little risk of complication. However, more careful preoperative examinations and postoperative managements should be necessary for a higher success-rate.