Dissolution of presumed calcareous corneal degeneration with 13.8% ethylenediaminetetraacetic acid solution in 17 dogs.

PURPOSE: To describe a novel treatment for dissolving calcareous corneal degeneration (CCD)-associated mineral in 17 dogs with 13.8% ethylenediaminetetraacetic acid (EDTA) solution. METHODS: Cases seen between 2021 and 2023 were reviewed. Seventeen dogs with CCD associated with corneal ulcerations were treated with a mineral dissolution procedure using 13.8% EDTA solution. A diamond burr keratotomy (DBK) was subsequently performed in some cases when residual mineralization remained present. RESULTS: Of the 19 eyes (17 dogs) included in the study, 10 eyes (8 dogs) required a DBK procedure. One eye (one dog) required a repeat procedure 26 weeks following the initial procedure and two eyes (one dog) required a repeat procedure 24 and 37 weeks following initial treatment in the left and right eye, respectively. Mean follow-up time to last recheck for eyes not requiring a second chelation procedure was 20.4 weeks (range, 10-47 weeks). At the last follow-up examination for all 17 dogs, the CCD resolved in 26.3%, improved in 57.9%, and recurred in 15.8% of eyes. Complications occurred in two eyes (two dogs) and included an infected stromal ulcer at 2-week recheck and the creation of a 40% depth stromal defect immediately following debridement. Both complications were successfully addressed with medical management. CONCLUSIONS: The utilization of 13.8% EDTA solution appears to be an effective and safe means of treating lesions associated with CCD.

Hypokalemia associated with topical administration of dorzolamide 2% ophthalmic solution in cats.

OBJECTIVE: To evaluate the effect of dorzolamide 2% ophthalmic solution on serum potassium and other hematologic parameters in cats. MATERIALS AND METHODS: Part I: Medical records from a single institution were retrospectively reviewed. Inclusion criteria consisted of cats diagnosed with glaucoma for which appropriate clinicopathological data were available both prior to and after the initiation of therapy with dorzolamide 2% ophthalmic solution. Part II: Healthy adult cats were enrolled in a prospective double-masked, randomized, cross-over study. Either dorzolamide 2% ophthalmic solution or placebo was administered OU t.i.d. for 6 weeks. Serum potassium, sodium, chloride, glucose, ALP, and ALT levels were assessed every 2 weeks. After a 2-week washout period, each cat was given the opposite topical preparation, and the study process was repeated. RESULTS: Part I: Of the twenty-seven eligible cases, hypokalemia developed in 29.6% (n = 8). While female spayed cats were significantly more likely to become hypokalemic, serum potassium was not significantly affected by age, weight, dosing frequency, or number of eyes treated. Part II: Ten cats participated in the study. Potassium values were significantly lower in cats receiving dorzolamide 2% ophthalmic solution compared to placebo at each time point throughout the 6-week study period. Additionally, chloride values were significantly greater in the treatment group at week two and four compared to the placebo group. CONCLUSIONS: Administration of dorzolamide 2% ophthalmic solution has a measurable effect on serum potassium level in cats and may result in clinical hypokalemia. Therefore, routine electrolyte monitoring is advised for feline patients receiving this medication.

Effects of oral isosorbide and glycerol on intraocular pressure, serum osmolality, and blood glucose in normal dogs.

OBJECTIVE: To evaluate and compare the effects of oral isosorbide and glycerol on intraocular pressure (IOP), serum osmolality (SOSM), and blood glucose (BG) in normal dogs. METHODS: Ten normal dogs were administered an oral dose of either isosorbide (1.5 g/kg), glycerol (1.5g/kg) or control (water, 2 mL/kg) in a double blind protocol. Prior to dosing, baseline IOP, SOSM, and BG were measured in all dogs. IOP was subsequently evaluated every 30 min for 6h post-dosing. BG and SOSM were reassessed at times 1, 2, 4, and 6h post-dosing. After 1-week washout periods, every dog was subject to each of the three treatments. The dogs were held NPO for 4h after dosing. RESULTS: The maximal decrease in IOP was 17% by 1h and 13.5% by 30min after glycerol and isosorbide administration, respectively. However, the overall changes in IOP were not significant when compared to the controls. SOSM increased above baseline after dosing with glycerol but decreased after isosorbide, which difference was significant at 1, 2, and 4 h post-administration. BG significantly increased after administration of glycerol relative to the control but was not significantly affected by isosorbide. CONCLUSIONS: Neither glycerol nor isosorbide significantly affected IOP when compared to the control. However, glycerol induced significant elevations in both BG relative to the control and SOSM relative to isosorbide.