Evaluation of photoactivated chromophore for keratitis-corneal cross-linking (PACK-CXL) in feline infectious keratitis-patient demographics, treatment protocols, risk factors, and treatment outcome: a retrospective study.

OBJECTIVES: To describe patient demographics and treatment protocols in a population of feline patients undergoing photoactivated chromophore for keratitis-corneal cross-linking (PACK-CXL) as an adjunctive treatment for infectious keratitis. Furthermore, to determine the proportion of PACK-CXL treatment success in the population studied, explore risk factors for treatment failure, and provide recommendations for future PACK-CXL clinical studies. MATERIALS AND METHODS: Records from four veterinary ophthalmology practices were reviewed to identify eligible patients and extract data. Recorded variables included patient-related factors, ocular examination findings, PACK-CXL protocol parameters, and treatment outcome. RESULTS: Records for 153 cats (154 eyes) were included. Median age in the treatment success group was 8 years (interquartile range (IQR) 4-12), with a median ulcer depth of 30% (IQR 30-40). Median age in the treatment failure group was 10.5 years (IQR 4.75-12) with a median ulcer depth of 45.9% (IQR 30-75). Persian cats were the most represented brachycephalic breed (52 out of 64 cats). Modified PACK-CXL protocols were used, including fast energy delivery (134 eyes), and increased fluence (52 eyes). The overall proportion of success was 88% (95% CI 84-93), which was variable between clinics. Eighty-two of 89 mesocephalic cat eyes (92%), and 54 of 65 brachycephalic cat eyes (83%) were classified as treatment successes. CONCLUSIONS: PACK-CXL appeared to be a useful, adjunctive therapeutic modality for the treatment of infectious keratitis in the feline patient population presented here. Brachycephalic cats, older cats, and those with deeper ulcers may be at increased risk for treatment failure.

Topical 1% cyclosporine eyedrops for the treatment of crystalline corneal dystrophy in dogs.

Background: Crystalline corneal dystrophy (CCD) is the most common type of corneal lipidic deposition in dogs. CCD is a primary metabolic disorder of the corneal fibroblast featuring an accumulation of extracellular and intracellular lipid deposits. Corneal lipid deposits create a corneal opacity and modify the interfibrillar collagen distance, inducing light scattering. Corneal vascularization is not usually associated with the disease, but, in case of chronicity, cell death may produce inflammation, and new corneal vessels are developed. To the best of the authors' knowledge, this is the first report of a medical approach for CCD treatment in veterinary medicine. Aim: To evaluate the efficacy of topical 1% cyclosporine eyedrops (1% CsA) for the treatment of CCD in dogs. Methods: Medical records of dogs with CCD were retrospectively reviewed (2009-2020). Corneal opacification description (COD) [size (mm), depth, and opacification degree (0-3)] was evaluated at 0, 3, 6, 9, 12, and 15 months postinitial diagnosis. Dogs were classified into three groups: the control group (G0), the group receiving topical 1% CsA once per day (G1), and the group receiving topical 1% CsA twice daily (G2). Results: Ninety-two client-owned dogs (163 eyes) of different breeds, ages, and gender fulfilled the inclusion criteria. When compared to G0, where the eyes significantly increased COD (p < 0.001), G1 and G2 significantly decreased COD (p < 0.001). In fact, the probability of reducing COD was about three times higher in G2 than in G1, being nearly the same for the right [odds ratio (OR) = 2.94; 95% confidence interval (95% CI) = 0.55-15.78] and left eye (OR = 2.92; 95% CI = 0.49-17.26). In addition, for each additional month of treatment in G2, the probability of reducing COD increased significantly (OR = 1.12; 95%CI = 1.00-1.26 for the right eye and OR = 1.16; 95%CI = 1.02-1.32 for the left eye). Conclusion: Long-term treatment with topical 1% CsA eyedrops significantly improved CCD in dogs, being the probability of reducing COD higher when applying the treatment twice daily.

Clinical parameters obtained during tear film examination in domestic rabbits.

BACKGROUND: One of the contributing factors to ocular surface health is a stable precorneal tear film. Considering the increasing interest in rabbits as pets and the limited literature available on domestic rabbit tearing, the aim of this study was to establish normative data for examination of the tear film in domestic rabbits. RESULTS: The study included 75 client-owned domestic Holland Lop rabbits (150 eyes). The following examinations were performed in each eye: Schirmer tear test-1, tear osmometry, interferometry, tear meniscus height measurement and meibography (quantifying meibomian gland loss as a percentage). The resulting median (95% central range) values were 10.0 (5.0-17.3) mm/min for the Schirmer tear test-1, 345.0 (280.5-376.1) mOsm/L for tear osmolarity, grade 2 (1-4) of interferometry, 0.28 (0.20-0.47) mm for tear meniscus height and 0.0 (0.0-67.6) % meibomian gland loss. A significant association was found between tear osmolarity and age, with an estimated decrease of - 4.0 mOsm/L with each additional year of age (p < 0.001). The distributions of interferometry grades were significantly different between males and females (p < 0.001), with grade 1 and grade 2 being the most frequent in females and males, respectively. A weak negative correlation was also observed between interferometry grade and the percentage of meibomian gland loss (r = - 0.22, p = 0.006). CONCLUSIONS: This is an original study that documents extensive tear film parameters in healthy Holland Lop rabbits. The results can be used as normative data for the examination of the tear film in this lagomorph breed.

Conjunctival Extramedullary Plasmacytoma in Dogs and a Cat: Clinical Characteristics and Histopathological Findings.

BACKGROUND: Extramedullary plasmacytoma (EMP) is a plasma cell tumor that is very rarely reported in ocular and adnexal tissue and is usually solitary and benign. METHODS: This study evaluated seven cases from different ophthalmology referrals submitted for histopathological analysis between 2013 and 2022. RESULTS: EMPs were diagnosed in a 9-year-old domestic short-haired cat and in six dogs (median age, 10 years): three English Cocker Spaniels, a Golden Retriever, a Maltese, and a Pinscher. EMPs affected the third eyelid conjunctiva in five cases (5/7), followed by the superior bulbar (1/7) and palpebral conjunctivae (1/7), respectively, and were presented mostly as well-defined, salmon-colored nodules. Histopathologically, the masses were composed of sheets and packets of round cells morphologically consistent with mature plasma cells with mild anisocytosis and anisokaryosis; mitosis and binucleated giant cells were rarely observed. Follow up for 6/7 cases ranged from 6 months to 2 years. No signs of recurrence or systemic involvement (multiple myeloma) were observed. CONCLUSIONS: EMP should be included in the differential diagnoses of canine and feline conjunctival masses. Staging recommendations should include multiple myeloma diagnostic evaluation. Our results suggest that primary conjunctival EMP does not appear to be locally aggressive and has low systemic involvement behavior. The local surgical excision alone or combined with cryotherapy should be curative.

A multicenter retrospective evaluation of the prevalence of known and presumed hereditary eye diseases in Lagotto Romagnolo dog breed within a referral population in Italy (2012-2020).

OBJECTIVE: To describe the ophthalmological findings of Lagotto Romagnolo dog breed and to report the prevalence of Known and Presumed Hereditary Eye Diseases (KP-HED). ANIMALS STUDIED: Two hundred sixteen dogs were examined and included in this retrospective study. PROCEDURES: Medical records of Lagotto Romagnolo dogs between 2012 and 2020 were included. Data about the ocular status were collected through ocular screening examinations (OSE) or clinical ophthalmic examinations (COE). The prevalence of each KP-HED was expressed as a function of the total number of the KP-HED in this referral population. RESULTS: A total of 85 dogs (39.35%) were ophthalmologically healthy, ocular diseases presumably not hereditary were found in 43 dogs (19.91%), and 88 dogs (40.74%) were affected by one KP-HED. The most common KP-HEDs diagnosed were cataract (28/88; 31.82%), corneal endothelial dystrophy (17/88; 19.32%), retinal dysplasia (9/88; 10.23%), lens instability (7/88; 7.95%), progressive retinal atrophy (6/88, 6.82%), and keratoconjunctivitis sicca (6/88, 6.82%). Most of dogs with a KP-HED (77.27%, 68/88) were identified within COE group. CONCLUSIONS: To the authors' knowledge, this is the first report of the prevalence of ocular disease in the Lagotto Romagnolo dog breed within a referral population in Italy. This study suggests a relatively high prevalence of KP-HED, with a characteristic late-onset presentation in some diseases. Many of these KP-HED's, lead to ocular pain and irreversible blindness, for this reason, the authors highlight the importance of aiming for an early diagnosis. Breeder's efforts and breeding programs should be directed at limiting such disorders.

Comparison of conjunctival microbiota of clinically normal Persian cats with and without nasolacrimal duct obstruction.

OBJECTIVE: This study was performed to determine the conjunctival microbiota of Persian cats with and without nasolacrimal duct obstruction (NLDO). ANIMALS STUDIED: Twenty-five Persian cats: 15 with bilateral NLDO (Group A) and 10 with no NLDO (Group B). PROCEDURES: All fifty eyes were assessed. Sterile swab applicators were used for the collection of specimens, which were cultured. PCR was performed on conjunctival swab and blood samples for the detection of Mycoplasma spp. and feline herpesvirus 1(FHV-1), respectively. RESULTS: FHV-1 was detected in two cats in Group A. Twelve eyes from Group A and four from Group B were Mycoplasma spp. positive based on the PCR results. Moreover, fungal culture was positive in six eyes from Group A and three eyes from Group B. The dominant fungus isolated was Aspergillus spp. (6 out of 11 fungal isolates). Other isolated fungi were Alternaria spp. and Cladosporidium spp. Twenty-three eyes had positive bacterial culture in Group A, while twelve eyes were positive in Group B. The most commonly isolated bacteria were Staphylococcus epidermidis (15 out of 38 bacterial isolates). ß-hemolytic Streptococcus spp., Corynebacterium spp., and Staphylococcus aureus were isolated in similar proportions in both groups. Escherichia coli was also present in both groups. CONCLUSIONS: Results of this study revealed same isolated fungal and bacterial spp. and in similar proportions in Persian cats with and without NLDO.

Successful treatment of distichiasis in a cow using a direct-contact 810-nm diode laser.

OBJECTIVES: To describe the use of direct-contact diode laser as a new treatment for distichiasis. STUDY DESIGN: Case report. ANIMALS: A 2-month-old Italian Friesian calf with bilateral excessive tearing and corneal opacification was presented to the Visionvet Eye Clinic. Abnormalities on ophthalmic examination included epiphora, seromucous discharge, bilateral distichiasis and secondary chronic keratitis affecting both eyes. METHODS: Distichiae were surgically removed after insertion of the 810-nm diode laser tip into the associated meibomian gland. RESULTS: Clinical signs gradually improved postoperatively with minimal and transient post-operative complications. Ophthalmic examination was within normal limits 6 months later beyond distichiae. CONCLUSION: Treatment of distichiasis with direct-contact 810-nm diode laser resulted in long-term resolution of signs in the case described here.

Corneoconjunctival transposition for the treatment of deep stromal to full-thickness corneal defects in dogs: A multicentric retrospective study of 100 cases (2012-2018).

OBJECTIVE: To describe and evaluate the use of corneoconjunctival transposition (CTT) as a surgical treatment for canine deep stromal ulcers, descemetoceles, and full-thickness corneal defects and to determine its efficacy in preserving corneal graft transparency and vision. ANIMALS STUDIED: One hundred client-owned dogs with deep stromal ulcers, descemetoceles, or full-thickness corneal defects. METHODS: Medical records of canine patients that underwent CCT, from 2012 to 2018, were reviewed. Only, patients with preoperative positive consensual pupillary light and dazzle reflexes were included. RESULTS: There were 59 males and 41 females, from 0.3 to 17 years. Brachycephalic breeds were overrepresented (65%). All patients were unilaterally affected, with 16 deep stromal ulcers, 33 descemetoceles, and 51 corneal perforations, of a median (range) size of 4 (2-8) mm. The central cornea was affected in the majority of cases (57%), and euryblepharon and keratoconjunctivitis sicca were the most common concurrent ocular diseases (42% and 40%, respectively). The graft was most frequently harvested from dorsal (67%), and 9/0 absorbable suture material was used. Intraoperative and postoperative complications were seen in 7 and 21 cases, respectively. Mean follow-up time was 107.8 days. Vision was preserved in 96% patients, with 62% showing faint to mild opacification. Among the statistically analyzed variables, euryblepharon and pigmentary keratitis were found to be significantly associated with greater corneal graft opacification (P = .040 and P = .028, respectively). CONCLUSIONS: Corneoconjunctival transposition is an effective surgical treatment for deep stromal, descemetocele, and full-thickness corneal defects in dogs, achieving a highly satisfactory degree of corneal graft transparency and preserving vision.

Effect of body position, eyelid manipulation, and manual jugular compression on intraocular pressure in clinically normal cats.

OBJECTIVE: To determine the effect of body position, eyelid manipulation, and manual jugular compression on intraocular pressure (IOP) in clinically normal cats. ANIMAL STUDIED: TWENTY-ONE ADULT CLIENT-OWNED DOMESTIC SHORTHAIR CATS: PROCEDURES: The IOP was measured by means of rebound tonometer. A baseline IOP was measured in all cats in ventral recumbency with normal head position (horizontal to the ground) with no pressure on the neck or eyelids. To measure the IOP in dorsal recumbency, each cat was held in the dorsal recumbency position for 5 min. Four different manipulations were used, including maximal dorsoventral extension of the eyelids, lateral eyelid extension, manual compression of the ipsilateral jugular vein, and manual compression of both jugular veins. IOP after all the manipulations was measured in ventral recumbency. RESULTS: Overall the mean ± SD IOP values of all eyes in ventral recumbency, dorsal recumbency, maximal dorsoventral extension of the eyelids, lateral eyelid extension, compression of the right jugular vein, compression of the left jugular vein, and compression of the both jugular veins were 16.1 ± 2.9 mmHg, 17.1 ± 5.0 mmHg, 21.7 ± 5.8 mmHg, 22.4 ± 5.6 mmHg, 15.0 ± 3.7 mmHg, 14.9 ± 3.7 mmHg, and 16.1 ± 4.6 mmHg, respectively. IOP was increased significantly in maximal dorsoventral extension of the eyelids (P = 0.001) and lateral eyelid extension (P = 0.001) compared to baseline. CONCLUSIONS: Results of this study may be beneficial for clinicians to be aware of the effects of body position, traction, and compression of the eyelids and neck on IOP during ophthalmic examination in cats.

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.

Three cases of prolapse of the nictitans gland in cats.

We report three cases of adult cats showing a prolapse of the gland of the third eyelid. Three different breeds were affected: Burmese, Persian and Domestic Short-haired. In all cases, the disorder occurred spontaneously, without any other ocular sign. Surgical replacement of the gland was performed using the Morgan pocket technique. Good esthetic results were obtained, and no recurrence occurred.