Effect of three treatment protocols on acute ocular hypertension after phacoemulsification and aspiration of cataracts in dogs

Objective  To compare the effect of topical latanoprost, intracameral carbachol, or no adjunctive medical therapy on the development of acute postoperative hypertension (POH) and inflammation after routine phacoemulsification and aspiration (PA) of cataracts in dogs.
Design  Retrospective study.
Procedures  Dogs received either one drop of topical 0.005% latanoprost (21 dogs, 39 eyes), an intracameral injection of 0.3 mL of 0.01% carbachol (15 dogs, 30 eyes), or no adjunctive therapy (46 dogs, 90 eyes) immediately following PA of cataract(s). Intraocular pressure (IOP) was measured in all dogs 2 and 4 h after surgery. IOP was measured and aqueous flare assessed at 8 am the day after surgery.
Results  Carbachol-treated dogs had significantly higher mean IOP (33.2 ± SD 20.8 mmHg) 2 h after surgery than dogs receiving no adjunctive therapy (22.0 ± SD 14.1 mmHg) ( P  =  0 .049). There were no significant differences in IOP among groups at any other time point. There were no significant differences in number of POH episodes between dogs treated with carbachol (47%), latanoprost (29%), or dogs that received no adjunctive therapy (33%). There were no significant differences in mean aqueous flare grade between eyes treated with latanoprost (1.7 ± SD 0.4) or carbachol (1.4 ± SD 0.6), and eyes that received no adjunctive therapy (1.7 ± SD 0.4).
Conclusions  Topical 0.005% latanoprost or intracameral injection of 0.3 mL of 0.01% carbachol after PA in dogs did not reduce POH or increase intraocular inflammation compared to dogs not receiving adjunctive therapy after PA of cataracts.     

Topical KINOSTAT™ ameliorates the clinical development and progression of cataracts in dogs with diabetes mellitus

Objective To determine whether topical administration of the aldose reductase inhibitor Kinostat™ 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 Kinostat™ 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 Kinostat™.     

Topical treatment of non-healing corneal epithelial ulcers in dogs with aminocaproic acid

The potential efficacy of topical epsilon-aminocaproic acid, an antiplasmin agent, in the treatment of persistent corneal epithelial defects was evaluated in a study of the medical records of 44 dogs, in which 51 eyes had been diagnosed with a corneal epithelial defect lasting more than 10 days, with no apparent underlying cause. At an initial examination all the affected eyes had had non-adherent epithelium removed. Thirty-four of the eyes in 28 dogs examined between January 2000 and March 2003 were also treated by the topical application of a solution of 35.7 mg/ml ophthalmic aminocaproic acid three times a day; the other 17 eyes in 16 dogs treated between October 1997 and March 1999 had received only topical treatment with gentamicin in addition to the debridement. Both groups were assessed clinically at weekly intervals for a maximum of three weeks. The two groups had approximately the same breed distribution, and there were no statistically significant differences between them in terms of their age, sex, affected side or duration of the corneal erosions. After three weeks, 32 of the 34 eyes treated with aminocaproic acid (94.1 per cent) had been cured, compared with seven of the 17 eyes treated with gentamicin (41.2 per cent) (P=0.0001). No adverse drug reactions were reported.     

Development of glaucoma after cataract surgery in dogs: 220 cases (1987-1998)

OBJECTIVE: To examine postoperative ocular hypertension (POH) and other variables as predictors of the risk of developing glaucoma after cataract surgery in dogs. DESIGN: Retrospective study. ANIMALS: 220 dogs that had cataract surgery. PROCEDURE: Medical records of 220 dogs (346 eyes) that had extracapsular cataract removal or phacoemulsification of cataracts were reviewed. With respect to glaucoma development, 8 variables were analyzed, which included development of POH, breed, sex, age at time of surgery, eye (right vs left), phacoemulsification time, intraocular lens (IOL) placement (yes or no), and stage of cataract development. Eyes developed glaucoma within 6 or 12 months of surgery or did not have signs of glaucoma at least 6 or 12 months after cataract surgery. RESULTS: Of 346 eyes, 58 (16.8%) developed glaucoma after surgery. At 6 months, 32 of 206 (15.5%) eyes examined had glaucoma; at 12 months, 44 of 153 (28.8%) eyes examined had glaucoma. Median follow-up time was 5.8 months (range, 0.1 to 48 months). Mixed-breed dogs were at a significantly lower risk for glaucoma, compared with other breeds. Eyes with IOL placement were at a significantly lower risk for glaucoma, compared with eyes without IOL placement. Eyes with hypermature cataracts were at a significantly higher risk for glaucoma, compared with eyes with mature or immature cataracts. CONCLUSIONS AND CLINICAL RELEVANCE: Multiple factors appear to contribute to the onset of glaucoma in dogs after cataract surgery. Complications prohibiting IOL placement during cataract surgery may lead to a high risk of glaucoma development.     

Effects of topical application of a 2% solution of dorzolamide on intraocular pressure and aqueous humor flow rate in clinically normal dogs

OBJECTIVE: To evaluate effects of topical application of a 2% solution of dorzolamide on intraocular pressure (IOP) and aqueous humor flow rate in clinically normal dogs. ANIMALS: 15 Beagles. PROCEDURE: The IOP was measured in both eyes of all dogs for 3 days to determine baseline values. In a single-dose study, 50 microl of dorzolamide or control solution was applied in both eyes at 7:00 AM, and IOP was measured 7 times/d. In a multiple-dose study, dorzolamide or control solution was applied to both eyes 3 times/d for 6 days, and IOP was measured 4 times/d during treatment and for 5 days after cessation of treatment. Aqueous humor flow rate was measured for all dogs fluorophotometrically prior to treatment and during the multiple-dose study. RESULTS: In the single-dose study, dorzolamide significantly decreased IOP from 30 minutes to 6 hours after treatment. Mean decrease in IOP during this time span was 3.1 mm Hg (18.2%). Maximal decrease was detected 6 hours after treatment (3.8 mm Hg, 22.5%). In the multiple-dose study, dorzolamide decreased IOP at all time points, and maximal decrease was detected 3 hours after treatment (4.1 mm Hg, 24.3%). Mean aqueous humor flow rate decreased from 5.9 to 3.4 microl/min (43%) after treatment in the dorzolamide group. CONCLUSIONS AND CLINICAL RELEVANCE: Topical application of a 2% solution of dorzolamide significantly decreases IOP and aqueous humor flow rate in clinically normal dogs. Therefore, topical administration of dorzolamide should be considered for the medical management of dogs with glaucoma.     

Cataracts are not associated with retinal detachment in the Bichon Frise in the UK--a retrospective study of preoperative findings and outcomes in 40 eyes

Objective The aim of this study was to evaluate whether the Bichon Frise population in the UK is at the same risk of developing retinal detachment in association with cataract formation and following phacoemulsification as described in reports from the USA. Procedures The medical records of Bichon Frises which were presented for cataract assessment and of those which were treated with phacoemulsification at Willows Referral Service between 1997 and 2009 were reviewed. Results Forty eyes (26 dogs) with unilateral or bilateral cataracts were included in the study. There was no evidence of retinal detachment associated with the cataracts at initial presentation. Phacoemulsification was performed on 34 eyes (20 dogs). Clinically evident lens‐induced uveitis was treated preoperatively in 17/34 eyes. Artificial lens implantation was carried out in 30/34 eyes; automated anterior vitrectomy was performed in 7/34 eyes. The mean follow‐up time was 16.6 months (range 1.5–73 months). At the last re‐examination, 31/34 eyes (91.2%) were visual. Three eyes (8.8%) were blind – two (in the same dog) because of presumptive bilateral optic nerve disease and one because of uveitis and secondary glaucoma. There was no evidence of retinal detachment following phacoemulsification in any of the 34 eyes. Conclusion This study suggests that the Bichon Frise population in the UK does not appear to have a predisposition for retinal detachment in association with cataract formation or following cataract surgery. Prophylactic random transscleral laser retinopexy or transscleral cryopexy cannot therefore be routinely recommended for Bichon Frises with cataracts in the UK.     

Evaluation of electroacupuncture treatment for thoracolumbar intervertebral disk disease in dogs

OBJECTIVE: To evaluate use of electroacupuncture combined with standard Western medical treatment versus Western medical treatment alone for treatment of thoracolumbar intervertebral disk disease in dogs. DESIGN: Prospective controlled study. ANIMALS: 50 dogs with signs of thoracolumbar intervertebral disk disease. PROCEDURES: Dogs were randomly allocated to 1 of 2 treatment groups and classified as having grade 1 to 5 neurologic dysfunction. Dogs in group 1 received electroacupuncture stimulation combined with standard Western medical treatment; those in group 2 received only standard Western medical treatment. A numeric score for neurologic function was evaluated at 4 time points to evaluate effects of treatments. RESULTS: Time (mean +/- SD) to recover ambulation in dogs with grade 3 and 4 dysfunction in group 1 (10.10 +/- 6.49 days) was significantly lower than in group 2 (20.83 +/- 11.99 days). Success (able to walk without assistance) rate for dogs with grade 3 and 4 dysfunction in group 1 (10/10 dogs) was significantly higher than that of similarly affected dogs in group 2 (6/9 dogs). Dogs without deep pain perception (grade 5 dysfunction) had a success (recovery of pain sensation) rate of 3 of 6 and 1 of 8 in groups 1 and 2, respectively, but the difference was not significant. Overall success rate (all dysfunction grades) for group 1 (23/26; 88.5%) was significantly higher than for group 2 (14/24; 58.3%). CONCLUSIONS AND CLINICAL RELEVANCE: Electroacupuncture combined with standard Western medical treatment was effective and resulted in shorter time to recover ambulation and deep pain perception than did use of Western treatment alone in dogs with signs of thoracolumbar intervertebral disk disease.     

Retrospective study of prophylactic random transscleral retinopexy in the Bichon Frise with cataract

The objective of this study was to determine the efficacy of prophylactic random transscleral retinopexy (PRTR) in preventing rhegmatogenous retinal detachment (RRD) in the Bichon Frise with juvenile cataract. The medical records were reviewed from a private veterinary ophthalmology practice of nondiabetic Bichon Frise dogs younger than 11 years that had inherited cortical cataracts in one or both eyes and that had a follow-up examination after at least 9 months. Eyes were included in the study if the fundus could be visualized by indirect ophthalmoscopy at the last examination either because of phacoemulsification or resorption of the cataract. Four groups of eyes were identified. In group 1, no PRTR was performed and there was resorption of the cataract; in group 2, eyes had no PRTR performed and phacoemulsification of the cataract. Group 3 had PRTR performed and resorption of the cataract. In group 4, PRTR was performed as was phacoemulsification of the cataract. In group 1, 20 eyes had resorbed cataracts, and 12 (60%) of these had RRD. In group 2, 18 eyes had phacoemusification of the cataract, and 10 (55%) of these had RRD. In group 3, 19 eyes had PRTR and resorbed cataracts, and 2 (10%) of them had RRD. In group 4, 39 eyes had PRTR and phacoemulsification of the cataract; of these 5 (12%) had RRD. The Bichon Frise dog with inherited cataract is at high risk of RRD. PRTR reduces this risk.     

Phacoemulsification and acryl foldable intraocular lens implantation in dogs: 32 cases

This study evaluated the surgical outcome and complications of phacoemulsification and the implantation of an acryl foldable intraocular lens (IOL) with a squared edge in dogs with cataracts. Thirty-two eyes from 26 dogs were examined. The mean follow up period was 75.9 days ranging from 23 to 226 days. The complications after phacoemulsification were posterior capsular opacity (PCO) around the IOL (n = 11), ocular hypertension (n = 4), focal posterior synechia (n = 4), hyphema (n = 3) and corneal ulcer (n = 2). The complications associated with the IOL were decenteration of the optic (n = 2) and ventral haptic displacement (n = 1). Most cases of PCO were found only around the margin of the IOL, and all eyes had vision during the observation period. In conclusion, the implantation of an acryl-foldable lens with a squared edge at the time of phacoemulsification is an effective method for preserving the central visual field of dogs with cataract.     

Development of glaucoma after phacoemulsification for removal of cataracts in dogs: 22 cases (1987-1997)

OBJECTIVE: To determine factors contributing to glaucoma after lens extraction via phacoemulsification in dogs. DESIGN: Retrospective study. ANIMALS: 22 dogs (29 eyes) with glaucoma and 21 dogs (30 eyes) without glaucoma after phacoemulsification. PROCEDURE: Medical record review. RESULTS: Eyes at increased risk for glaucoma included those of Boston Terriers, those with uveal or retinal abnormalities before surgery, and those with intraoperative intraocular hemorrhage. Significant differences between groups were not detected for incidence of preoperative lens-induced uveitis, presence of an intraocular lens, or frequency of an acute postoperative increase in intraocular pressure. Glaucoma developed (mean +/- SD) 12.8+/-14.1 months (median, 10 months; range, 0.25 to 55 months) after surgery. Eighteen of 29 (62%) eyes with potential for vision after onset of glaucoma retained vision for a mean of 16.5+/-12.8 months (median, 10.8 months; range, 1.5 to 37 months) after glaucoma was diagnosed. Most of these eyes still had vision at the conclusion of the study period. CONCLUSIONS AND CLINICAL RELEVANCE: Risk factors identified by this study will aid in preoperative counseling of clients and refining selection criteria for candidates for phacoemulsification. Careful follow-up for the remainder of the dog's life after surgery may improve long-term success rates by permitting early intervention before intraocular pressure increases substantially and vision is irreversibly lost. Surgery for cataracts may still be worthwhile in dogs with increased risk of glaucoma, especially if elderly, because of the lengthy period to onset of glaucoma after surgery and the beneficial effects of treatment after glaucoma develops.     

Evaluation of client perceptions concerning outcome of cataract surgery in dogs

OBJECTIVE: To compare client perception of outcome of phacoemulsification in dogs with information obtained from medical records. DESIGN: Retrospective cohort study. ANIMALS: 108 dogs (203 eyes) undergoing phacoemulsification from May 1999 through April 2004. PROCEDURE: Data obtained from medical records included signalment, presence of diabetes mellitus, cataract stage, whether surgery was unilateral or bilateral, intraocular lens (IOL) placement, and postoperative complications. Owners completed a survey concerning outcome of phacoemulsification in their dog. Survey responses from owners classified as satisfied or dissatisfied with the outcome of phacoemulsification on the basis of their willingness, in retrospect, to have the surgery performed again were compared. RESULTS: Data from medical records and survey responses were available for 108 dogs (203 eyes). Median follow-up was 3 months via medical record review and 12 months via owner survey responses. Most (81%) owners were satisfied with outcome. The most common reason for dissatisfaction was loss of vision after surgery; however, most dissatisfied owners did not return their dog for examinations. Owner perception of success was not associated with patient age, sex, presence of diabetes mellitus, cataract stage, or IOL placement in at least 1 eye but was associated with perceived improvement of their pet's vision and activity level. Dissatisfied owners were significantly more likely to report that explanation of risks and complications before surgery was inadequate. CONCLUSIONS AND CLINICAL RELEVANCE: Owner perception of outcome after phacoemulsification in dogs was highly favorable. However, surgical risks and the importance of postoperative examinations, particularly in dogs undergoing visual deterioration, must be conveyed to clients.     

Clinical features and outcomes of phacoemulsification in 39 horses: a retrospective study (1993-2003)

OBJECTIVE: To identify visual outcome and postoperative complications following phacoemulsification of equine cataracts. ANIMALS: Records of 39 horses (55 eyes) with cataracts were reviewed. METHODS: Eyes with cataracts removed by phacoemulsification were included in the study. Data collected included age, breed, sex, stage and etiology of cataract, unilateral vs. bilateral involvement, and ultrasound findings. Horses were grouped by etiology of the cataract. Visual outcome and complications were evaluated for each group and the overall population. RESULTS: Immediately postoperatively 46 out of 47 eyes (98%) were sighted. Four weeks postoperatively 23 of 29 operated eyes (79%) were sighted [13/18 (72%) eyes with congenital/juvenile onset, 6/6 (100%) eyes with traumatic and 4/5 (90%) eyes with uveitis-induced cataracts], with 18 eyes lost to follow-up. The most common postoperative complications included corneal edema (19 eyes/40%), fibrin in the anterior chamber (11 eyes/23%), postoperative ocular hypertension (9 eyes/19%), synechia/dyscoria (9 eyes/19%), and hyphema (7 eyes/15%). CONCLUSIONS: Prognosis for vision is favorable for horses following phacoemulsification and planned posterior continuous tear circular capsulorrhexis. Success rates depend on age of patient, cause of cataract and pre-existing intraocular disease. The highest success rate occurred in eyes with traumatic cataracts.     

Visual outcome in a group of dogs with ocular blastomycosis treated with systemic antifungals and systemic corticosteroids

OBJECTIVE: To evaluate the success of the use of systemic corticosteroids and antifungal medications in the treatment of dogs with ocular lesions associated with systemic blastomycosis. DESIGN: Retrospective study. ANIMALS STUDIED: Medical records of 25 dogs diagnosed with blastomycosis, via either cytology or histopathology, at the Purdue University Veterinary Teaching Hospital between 1 January 2000 and 1 January 2005, were reviewed. PROCEDURE: Data collected from the medical records included signalment, presence and progression of ocular lesions, antifungal drugs administered, oral and topical corticosteroid administration, length of follow-up, response to treatment, and visual outcome. RESULTS: Of the 25 cases reviewed, 12 dogs (19 eyes) with follow-up information were found to have lesions consistent with ocular blastomycosis. Length of follow-up in the 12 cases ranged from 1 month to 31 months with a mean of 9 months. Antifungal therapy for all cases consisted of oral itraconazole (5 mg/kg every 24 h) initially. In seven cases, the antifungal drug administered was changed from itraconazole to oral fluconazole. Two of these also received intravenous amphotericin B, and two received additional treatment with itraconazole. All 12 dogs also received oral prednisone. The dose of oral prednisone utilized ranged from 0.2 mg/kg/day to 1.4 mg/kg/day with a mean of 0.7 mg/kg/day; the duration of oral prednisone administration ranged from 2 weeks to 8.5 months with a mean of 3 months. Topical prednisolone was a component of the treatment of 16 of the 19 eyes. Duration of topical prednisolone treatment ranged from 1 month to 30 months with a mean of 5 months. Lesions not located in the eyes exhibited a positive response to treatment in 11 (92%) of the 12 dogs. Overall, 14/19 (74%) affected eyes were visual at the time of their final recheck. All eyes with mild or moderate lesions and 5/10 (50%) severely affected eyes were visual at their last recorded recheck examination. CONCLUSIONS: The administration of systemic corticosteroids did not appear to adversely affect the survival rate and might have played a role in preservation of vision in a majority of dogs in this group with ocular blastomycosis.     

Multi-centre assessment of mycotic rhinosinusitis in dogs: a retrospective study of initial treatment success (1998 to 2008)

Objectives : To retrospectively review the first treatment response of dogs with mycotic rhinosinusitis to commonly utilised treatment techniques. Methods : Medical records of dogs treated for mycotic rhinosinusitis were obtained retrospectively via a manual review of the clinical databases of six veterinary referral centres for the period of January 1998 to June 2008, and first treatment outcome was evaluated. Historical and clinicopathological findings were also reviewed to evaluate their impact on treatment success or failure. Results : There was no significant difference in first treatment outcome between treatment groups (P=0·21). When all topical treatments were considered together (n=85), 39 dogs (45·8%) had a successful first treatment. Initial treatment success was associated with a younger age (56·3 versus 75·8 months; P=0·02) and was 2·7 times more likely in dogs with unilateral disease, although this was not significant (P=0·07). Adjunctive therapy with systemic antifungal agents was associated with treatment failure (PÄ0·01). Fifty-nine dogs (69·4%) responded successfully following multiple treatments. Clinical Significance : Treatment of mycotic rhinosinusitis remains challenging, and multiple treatments are frequently required for adequate treatment. Reasons for first treatment failure are likely multifactorial in origin, making it difficult to predict those dogs that are likely to have a superior prognosis, regardless of the treatment type used.     

Chronic retinal detachment and giant retinal tears in 34 dogs: outcome comparison of no treatment, topical medical therapy, and retinal reattachment after vitrectomy

The outcomes of dog's eyes with chronic (> 1 month) retinal detachment and giant retinal tears without therapy were compared with those treated with topical steroids and antiglaucoma medications, and with those that received a vitrectomy, retinal reattachment, endolaser therapy, and silicone oil tamponade. Fourteen of 16 eyes that did not receive therapy developed uveitis and secondary glaucoma, and were enucleated (4) or eviscerated (6); and 2 dogs were euthanized due to blindness and uveitis. Two eyes in 2 dogs remain without treatment, 1 and 3 years later. Fifteen of 19 eyes that received topical therapy developed nonresponsive uveitis and secondary glaucoma, and were enucleated (4) or eviscerated (9), 1 dog that was affected bilaterally was euthanized; and 3 eyes remain on topical anti-inflammatory therapy and the medication has been discontinued on 1 eye. Four of 6 eyes surgically reattached remain without clinical manifestations of uveitis and secondary glaucoma and 3 of these eyes have functional vision. Light microscopic observations completed on failed globes in the 3 groups were similar.     

Extracapsular cataract extraction: an analysis of 240 operations in dogs

A total of 240 extracapsular cataract extractions were performed on 214 dogs at the University of Illinois between 1968 and 1980. Overall success of the surgery, defined as restoration of functional vision for at least 6 weeks after surgery, was 79%. The success rates, on the basis of various parameters, were compared with the following results. The greater the number of years experience each surgeon had, the greater the surgical success rate. In dogs in which a second eye was operated on, the overall success rate on the second eye was approximately 20% less than that for the study as a whole. There was a significant difference in success rates between surgery on congenital and juvenile cataracts when compared with surgery on diabetic and senile cataracts, the first being 15% higher than the second. The success rate was 18% less for lensectomy with concurrent iridectomy than for lensectomy without iridectomy. There was no significant difference in success rates among the 3 procedures for extracapsular extraction used in this study, nor among the various breeds studied. There was no significant difference in the success rate of surgeries on the left eye, compared with surgeries on the right eye.     

Posterior capsular opacification in diabetic and nondiabetic canine patients following cataract surgery

Posterior capsular opacification (PCO) is the most common postoperative complication of contemporary cataract surgery. Limited information is available regarding PCO formation and factors that influence PCO development in the dog. Two hundred sixty-five eyes (144 from diabetic dogs and 121 from dogs with breed-related cataracts) were prospectively evaluated for PCO formation for up to 12 months postoperatively. The mean age of all dogs in the study was 7.77 years and diabetic dogs were significantly older than dogs with breed-related cataracts. There were 73 males (61 neutered, 12 intact) and 74 females (70 neutered, 4 intact) in the study. Statistical analysis was performed based on age, breed/size, gender, stage of cataract at the time of surgery, PCO score at each time point, breed-related vs. diabetic cataract, right eyes compared to left eyes, and presence/absence of uveitis. Age and gender did not significantly influence PCO formation. Small and medium-sized breeds developed significantly more PCO in comparison to the large/giant breeds at 2 weeks and 2-4 months postoperatively, but the differences were not significant at later time points. There was an overall significant increase in PCO formation in eyes with early immature cataracts when compared to other stages of cataract up to 4 months postoperatively but not at later time points. There were no statistical differences in PCO score at 6 months or at 1 year postoperatively in eyes with breed-related and diabetic cataracts. Right eyes did not differ from left eyes in PCO score. PCO score significantly increased over time in breed-related and diabetic groups and in the overall population. No difference was found in the degree of PCO formation in eyes with inflammation prior to or after surgery compared with those without inflammation. In summary, age, gender, presence of inflammation, and cause of cataract (breed-related vs. diabetes mellitus) do not influence the development of PCO in canine cataract dogs. Small and medium-sized breeds develop significant PCO earlier than larger breeds. It is important to note that all eyes from all dogs in this study developed PCO in a time dependent manner.     

Canine cataracts, diabetes mellitus and spontaneous lens capsule rupture: a retrospective study of 18 dogs

OBJECTIVE: To describe the clinical presentation and surgical outcome of diabetic canine patients with cataracts and preoperative spontaneous lens capsule rupture. ANIMALS STUDIED: A total of 20 dogs and 40 eyes were included in the retrospective evaluation. The patients' ages ranged from 5 to 14 years (mean 8.5 years). RESULTS: All dogs had clinical diabetes mellitus, with the duration since diagnosis ranging from 30 to 240 days (mean 123 days). Cataracts were bilateral and noted to have been present for 14-112 days (mean 39 days). Of the 40 eyes affected with cataracts, 30 had a spontaneous rupture of the lens capsule prior to surgery. The capsular rupture was diagnosed on clinical examination in 28/30 eyes and was noted intraoperatively in 2/30. The location of the capsular rupture was equatorial in 29/30 and posterior in 1/30 eyes. Surgery was performed in 38/40 eyes, with one case lost to follow-up without surgical intervention. Prior to surgery, routine diagnostic ophthalmic examination, ocular ultrasound, electroretinography, and systemic evaluation were performed in all dogs. Surgical procedures included phacoemulsification in 28/40 eyes, with IOL placement performed in 20/28 eyes. Intrascleral prosthesis placement or enucleation was performed in 8/40 and 2/40 eyes, respectively, due to a significantly reduced ERG or secondary glaucoma. CONCLUSIONS: The duration of clinical follow-up (19/20 dogs) ranged from 1 to 36 months (mean 12.9 months). All eyes that had cataract surgery with or without IOL placement were sighted at the time of the last follow-up examination. Spontaneous lens capsule rupture associated with diabetes mellitus, cataract and rapid lens intumescence occurs in the dog. Early surgical intervention, prior to secondary complications of glaucoma and loss of retinal function, is associated with a favorable outcome.     

The relationship of cataract maturity to intraocular pressure in dogs

Objective To determine the distribution of intraocular pressure, as measured by applanation tonometry, in dogs with cataracts, and compare these tonometric results to the different stages of cataract formation (incipient, immature, mature, and hypermature). Animals studied Retrospection study of canine clinical patients (86 dogs). Procedures All records of dogs presented from 1991 to 1996 to the university veterinary medical teaching hospital for diagnosis of cataracts and evaluation for cataract surgery were reviewed. The tonometric measurements from the initial ophthalmic examination were selected in cataractous and nonglaucomatous eyes either receiving no topical or no systemic medications. The stage of cataracts was based on the degree of opacification, tapetal reflection, clinical vision, and visibility of the ocular fundus by indirect ophthalmoscopy. The distribution of tonometric results were grouped by the cataract maturity, and compared by anova and Tukey’s general linear tests. Results Intraocular pressure with incipient cataracts ranged from 9 to 17 mmHg (mean 12.7 ± 1.2 mmHg). Intraocular pressure with immature cataracts ranged from 3 to 27 mmHg (mean 13.6 ± 0.6 mmHg). For the mature cataracts, IOP ranged from 5 to 22 mmHg (mean 11.9 ± 0.7 mmHg). For the hypermature cataract group, IOP ranged from 4 to 23 mmHg (mean 10.8 ± 0.6 mmHg). Comparison of the tonometric results among the different stages of cataract formation indicated a significant difference (P = 0.0086) between only the immature and hypermature groups. Conclusions Intraocular pressure in lens‐induced uveitis (LIU) is lowered but the relationship to the stage of cataract maturity is less clear. Significant tonometric differences were present between the immature and hypermature cataract groups, but these differences are too small to be clinically useful. Decreased intraocular pressure of dogs with all stages of cataract formation suggests concurrent LIU during all stages of cataract formation, especially with the mature and hypermature stages. The average tonometric measurements in dogs with these cataracts were about two standard deviations below the mean IOP reported in normal dogs.     

Effects of topical administration of an aldose reductase inhibitor on cataract formation in dogs fed a diet high in galactose

OBJECTIVE: To determine effects of a topical formulation of an aldose reductase inhibitor (ARI) on the development of sugar cataracts in dogs fed a diet high in galactose. Animals-Ten 6-month old Beagles. PROCEDURES: Dogs were fed a diet containing 30% galactose, and after 16 weeks, 6 dogs were treated topically with a proprietary ARI formulation and 4 dogs were treated with a placebo. Cataract formation was monitored by means of slit-lamp biomicroscopy and fundus photography. Dogs were euthanized after 10 weeks of treatment, and lenses were evaluated for degree of opacity, myo-inositol and galactitol concentrations, and concentration of the ARI. RESULTS: All dogs developed bilateral cortical opacities dense enough to result in a decrease in the tapetal reflex after being fed the galactose-containing diet for 16 weeks. Administration of the ARI arrested further development of cataract formation. In contrast, cataracts in the vehicle-treated dogs progressed over the 10-week period to the mature stage. Evaluation of the isolated lenses after 26 weeks of galactose feeding indicated that lenses from treated dogs were significantly less optically dense than lenses from control dogs. Lenticular myo-inositol concentration was significantly higher in the treated than in the control dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that topical application of a proprietary ARI formulation may arrest or reverse the development of sugar cataracts in dogs fed a diet high in galactose. This suggests that this ARI formulation may be beneficial in maintaining or improving functional vision in diabetic dogs with early lens opacities.