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Spontaneously occurring ocular neoplasia is rarely reported in rabbits. This case series presents four cases of rabbits diagnosed with iridociliary tumors, which have not been previously reported in this species. Major pathological findings include epithelial tumors affecting the anterior uvea with variable pigmentation and basement membrane formation. Follow‐up information was only available for two cases, but neither showed evidence of metastasis, suggesting that the prognosis for these tumors in rabbits, as in other species, may be very good. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To describe the presentation of 15 rabbits with naturally occurring cataracts referred for phacoemulsification surgery, the procedure in 13 cases and the follow‐up in 12. Animals included: Fifteen rabbits (30 eyes), nine of which stopped following visual cues in association with cataract progression. Materials and Methods: Rabbits underwent preoperative ophthalmic and ocular ultrasound examination. Results: Thirteen rabbits (22 eyes) had mature cataracts. Ten were bilateral and three unilateral. Two rabbits had an anterior chamber abscess. The cataract in one of these was incipient. One rabbit had bilateral immature cataracts. One rabbit had a subluxated lens, and one had a retinal detachment. Thirteen rabbits (22 eyes) underwent phacoemulsification. Eighteen, 13.5‐mm capsular tension rings (CTRs) and seventeen, 13‐mm IOLs (Acrivet®, Berlin, Germany) were fitted including one 41D 60V‐model, and three 49D and thirteen 58D 20S‐models. Intraoperative complications included one unilateral posterior‐capsular tear, one lens subluxation, and one expulsive choroidal hemorrhage. One rabbit died during anesthetic recovery. Nine cases were PCR‐tested for Encephalitozoon cuniculi, and only three were positive. The median follow‐up time was 12 months (4‐24 months). Rabbits that were not following visual cues preoperatively did so postoperatively, and surgery resulted in a clear visual axis for the follow‐up period in every case except in two, due to reasons other than the surgery. Conclusions: Phacoemulsification with CTR and IOL implantation offers good long‐term results and can improve the quality of life of pet rabbits. Retinal detachment, lens luxation, expulsive choroidal hemorrhage, and anesthetic death are potential complications. [ABSTRACT FROM AUTHOR]

Objectives To calculate the size and dioptric power of a posterior chamber intraocular lens ( IOL) to achieve emmetropia in adult rabbits and to compare the dioptric power calculation results using a proprietary predictive formula to a retinoscopy-based method. Animals studied Three wild rabbit cadavers, seven pet rabbits with cataracts and ten healthy pet rabbits. Materials and Methods Implant size was calculated using a capsular tension ring ( CTR) (Acrivet®, Berlin, Germany). Published and cadaveric biometric data were used in the predictive formula. An IOL power-escalation study compared the predicted values to the refraction results of one pet rabbit (P1) fitted with a + 41D canine IOL (Acrivet®) and six pet rabbits (P2-P7) fitted with prototype IOLs (Acrivet®). Retinoscopy of 10 healthy pet rabbits served as controls. Results A 13.5 mm CTR fitted in all rabbits and permitted the use of a 13 mm IOL. The predicted IOL power ranged between +24D and +25D. The +41D IOL resulted in a refraction error of +8D. Progressive recalculation through a calibration formula led to the insertion of three +49D IOLs in two pet rabbits and a refraction of +6D to +8D, followed by seven +58D IOLs in four pet rabbits and a refraction median of 0D (range: −1.5D to +1D). Conclusions A 13 mm prototype IOL of +58D achieves emmetropia and is of adequate size for rabbits. The combined use of a CTR and retinoscopy is a useful method to calculate the size and refractive power of a new, species-specific, veterinary IOL. [ABSTRACT FROM AUTHOR]

This report describes the clinical presentation, diagnosis, and medical management of a 2-year-old spayed female dwarf rabbit ( Oryctolagus cuniculus) suffering from an ulcerative keratitis and a stromal abscess with a rapid evolution. The diagnosis of fungal keratitis was based on fungal culture identifying the pathogen as Aspergillus fumigatus. Treatment by topical terbinafine was efficacious in resolving the keratomycosis within 8 weeks. To our knowledge, this is the first reported case of spontaneous keratomycosis in a rabbit and the first description of successful therapy by terbinafine. [ABSTRACT FROM AUTHOR]

A 3-month wild rabbit was presented for examination of ocular opacities in the left eye. A complete bilateral ocular examination including slit-lamp examination, indirect ophthalmoscopy, tonometry, and ultrasound biomicroscopy was performed. Biomicroscopy of the lens of the left eye showed a retrolental fibrovascular membrane causing leukocoria. The opacity prevented biomicroscopy of the vitreous and funduscopy OS. No other disorder was present in either eye. Ultrasound examination did not show any difference between the right and left eye. Histopathological examination showed a 50-μm thick, preretinal, retrolental, nonpigmented, fibrovascular tissue. Posterior synechiae were present, but no other lesion of the posterior segment was found in this eye. These ocular abnormalities are consistent with a persistent hyperplastic tunica vasculosa lentis and persistent hyperplastic primary vitreous ( PHTVL/ PHPV), similar to those described in other species. [ABSTRACT FROM AUTHOR]

Objective To evaluate endodontic paper point tear test ( PPTT) in rabbits and compare changes in corneal touch threshold ( CTT) induced by Schirmer tear test ( STT) and PPTT. Normal corneal sensitivity recovery time after both tear tests was also measured. Also, mean PPTT and STT values were obtained. Methods Tear production of 20 eyes, from 10 rabbits, was evaluated using STT and the PPTT. Central corneal touch threshold was measured by a Cochet-Bonnet esthesiometer before any tear test was performed (zero time), immediately after the test (1 min), and consecutively at 6, 11, 16, and 26 min. Tests were conducted on three consecutive days: Day 1 - control condition, no tear tests performed only the CTT; Day 2 - CTT before and after PPTT; and Day 3 - CTT before and after STT. CTT values were compared using repeated measures ANOVA. Results Corneal touch threshold was significantly increased for at least 16 min after STT, indicating STT causes corneal discomfort. No difference was found between CTT following PPTT and controls, indicating PPTT caused minimal corneal discomfort. The mean (± SD) value for STT was 5.2 ± 1.0 mm/min and for PPTT was 13.8 ± 1.5 mm/min. Discussion The aqueous fraction of rabbit's tears can be successfully measured by PPTT. This report established reference values for PPTT in rabbits. Additionally, the absence of a significant difference in CTT after PPTT compared with controls shows that PPTT is well tolerated by rabbits. Considering the improved comfort (compared with STT), accuracy, and low cost, PPTT is a bona fide method of measuring aqueous tear production in rabbits. [ABSTRACT FROM AUTHOR]

This case report describes the clinical manifestations and ocular pathology of an intraocular sarcoma in a spayed female 7-year-old rabbit that developed clinical signs consistent with phacoclastic uveitis at 6 months of age, which was left untreated for most of the next 6 years. Ophthalmologic examination confirmed pupillary occlusion, aqueous flare, fibrin, and lens debris within the anterior chamber of the right eye. The right eye was blind and phthisical. The tentative clinical diagnosis was chronic phacoclastic uveitis, and a routine transconjunctival enucleation of the right eye was completed. The globe was formalin-fixed and submitted for histologic examination. Light microscopic examination revealed a ruptured cataractous lens, uveitis, retinal detachment, and an intraocular sarcoma centered around the lens. Immunohistochemical ( IHC) staining was positive for smooth muscle actin and vimentin and negative for Desmin and cytokeratin intermediate filaments. [ABSTRACT FROM AUTHOR]

Objective To document the thickness of the central cornea in pigmented rabbits using spectral-domain anterior segment optical coherence tomography (AS-OCT). Animals studied Seventeen pigmented rabbits (6 male, 11 female, both eyes) were involved in this study. Procedures Thirty-four eyes from healthy pigmented rabbits underwent a complete ophthalmologic examination, including AS-OCT. Eight radial scans, 6 mm in length and centered on the cornea, were obtained using the AS-OCT. Corneal thickness was automatically calculated using pachymetry software. Measurements were displayed as the mean and standard deviation for each of the 17 regions defined by the software. The regions were the center (1 mm radius, area a), the inner ring (2.5 mm radius, area b), the outer ring (3 mm radius, area c), and the eight radial scan lines in eight directions (Superior (1), SN (2), Nasal (3), IN (4), Inferior (5), IT (6), Temporal (7), ST (8)) with an angle of 45° between each consecutive scan line (a, b 1-8, c 1-8). Results There was no statistically significance difference in corneal thickness between gender, eye, and the eight directions ( P = 0.804, P > 0.05, P > 0.05). There was a statistical difference between the thickness in areas a, b, and c ( P < 0.05). The corneal thickness increased gradually from the center to the periphery of the 6 mm measured. The center corneal thickness was 387 ± 19.8 μm for OD and 384 ± 20.2 μm for OS. The corneal thicknesses of the thinnest point of the right eyes (OD) and the left eyes (OS) were 376 ± 20.2 and 370 ± 16.8 μm, respectively. There was positive correlation between the thinnest point and area a in both the right eyes ( r = 0.892, P < 0.001) and the left eyes ( r = 0.832, P < 0.001). Conclusions This is the first documentation of the rabbit corneal thickness in vivo using the spectral-domain AS-OCT. Pigmented rabbit corneas were almost 150 μm thinner than human corneal values. Gender and eye were not associated with any statistical differences in central corneal thickness in this study. [ABSTRACT FROM AUTHOR]

Objective To document the clinical presentation, diagnostics, treatment, and clinical outcome of rabbits with dacryocystitis. Materials and methods This retrospective study included 28 rabbits diagnosed with dacryocystitis. Available records of clinical and ophthalmological examinations, bacteriological samplings, diagnostic imaging, and treatment were reviewed. A telephone survey of the owners was conducted to evaluate recovery and recurrences. Results The mean age of the 28 rabbits presenting with ocular discharge from the nasolacrimal duct was 4.4 years. In 25 rabbits (89%), dacryocystitis was a unilateral finding. No underlying cause could be determined in 10 animals (35%). Dental malocclusion was observed in 14 rabbits (50%) and rhinitis in two animals (7%), with one animal showing both symptoms (4%). One rabbit (4%) presented with panophthalmitis. Most animals (96%) received topical antibiotic treatment. If necessary, additional topical (acetylcysteine, vitamin A ointment, nonsteroidals) or systemic treatment (antibiotics, nonsteroidals, paramunity inducer, and glucocorticoids) was provided. The mean duration of therapy was 5.8 weeks. The nasolacrimal duct was flushed in 27 of 31 affected eyes (87%). Dentistry was performed in 80% of the animals suffering from malocclusion. Regarding the clinical outcome, 12 animals (43%) showed complete recovery, eight rabbits (28%) were euthanized, three (11%) died due to unrelated causes, and three (11%) were lost to follow-up. Two rabbits (7%) continue to display signs of dacryocystitis and are being treated symptomatically by the owners. Conclusions This study reports the clinical presentation, treatment, and outcome of dacryocystitis in rabbits and outlines the importance of examination of the oral cavity, diagnostic imaging, and bacteriologic sampling. [ABSTRACT FROM AUTHOR]

Objective An n-butyl-ester cyanoacrylate adhesive available for veterinary surgery ( Vetbond® , 3M) was tested in rabbits for corneal irritation. Procedures Two experimental procedures were used on 24 rabbits: injection of the adhesive into an intralamellar corneal pocket (n = 10) and application of the glue to a mid-stromal corneal defect (n = 14). In both experiments the eyes were examined for 20 days for evidence of corneal irritation and tolerance. At the end of each experiment, histopathologic studies were performed on all corneas. Results The corneal reaction to the intrastromally injected cyanoacrylate was characterized clinically by slight edema and vascularization localized to the vicinity of the adhesive. A moderate foreign body-type reaction was found histologically. Following application of the adhesive to a central stromal defect, the treated corneas remained totally clear and histopathologic examination showed that the healing process was not altered compared to the controls. The mean retention time of the glue patch was 14 days. Conclusions Intrastromal injection and surface application to a corneal defect of n-butyl-ester cyanoacrylate to a corneal defect induced only a mild inflammatory response and did not interfere with the reparative process. These findings suggest that this surgical adhesive would be acceptable for treating corneal ulcerations in animals. [ABSTRACT FROM AUTHOR]

Abstract A rarely described ocular lesion in the rabbit is presented following the observation of four cases. It is a membrane of conjunctival origin that advances progressively, without adhering, towards the center of the cornea. Clinically the lesion in rabbits looks like pterygium in man, but with several differences: in rabbits, the conjunctival fold is absolutely free and does not penetrate into the superficial corneal layers. It originates from all the limbal circumference in a symetric growth. The cornea itself remains unaltered. The fold consists of fibroblasts and collagen. The microscopic findings suggest the lesion is possibly of a collagenous dysplasia. [ABSTRACT FROM AUTHOR]

To measure intraocular structures in New Zealand White breed rabbits ( Oryctolagus cuniculus Linnaeus, 1758) using A-mode and B-mode ultrasound with a 20 MHz transducer. In this study, the eyes of 15 rabbits were evaluated for determination of intraocular measurements using an ophthalmic ultrasound unit able to operate in both A and B-modes. The distances from the cornea to the anterior capsule of the lens (D1), from the anterior capsule of the lens to the posterior capsule of the lens (D2), from the posterior capsule of the lens to the retina (D3) and the complete length of the eye, which corresponds to the distance from the cornea to the retina (D4) were taken. The mean values obtained were 2.70 mm (±0.22 mm) for D1, 7.32 mm (±0.40 mm) for D2, 7.10 mm (±0.45 mm) for D3 and 17.12 mm (±0.41 mm) for D4. Statistical analyses using the Student's t-test showed that there were no differences between the eyes. The study was feasible without the need of pharmacological restraint and yielded normal mean values for ocular sonographic biometry in rabbits. [ABSTRACT FROM AUTHOR]