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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., (© 2016 American College of Veterinary Ophthalmologists.)

Objective: To obtain images of anterior and posterior segments of the eye using a slit-lamp (SL)/spectral domain (SD) optical coherence tomography (OCT) integrated system designed for the human eye, in the cat, dog, minipig and monkey., Animals Studied: One healthy adult monkey, one healthy adult minipig, one healthy adult dog, one healthy adult cat, and three cats and four dogs affected by corneal or retinal diseases., Procedure: A SL SCAN-1 SD-OCT, which is a slit-lamp SL-D7 that contains an integrated OCT module and a fundus viewer, was used to generate OCT images (512-2048), while simultaneously taking 'en-face' slit-lamp images (efSL). OCT images were obtained under sedation or anesthesia. These images were compared to histological retinal sections obtained from a monkey, a minipig, a dog, and a cat., Results: 'en-face' slit-lamp images and OCT images of the ocular tissues were obtained allowing for the identification of different corneal and retinal layers in all animal species. Measurements of the total retinal thickness (TRT) from the inner limiting membrane to the retinal pigment epithelium were performed in various regions throughout the retina. Reduction in TRT was consistent with clinical features of retinal degeneration identified in dogs and cats., Conclusion: This noninvasive procedure is useful for both experimental and clinical assessments of ocular tissue damage. Images of anterior and posterior segments are readily obtained under routine clinical conditions. Future studies are warranted to establish normal OCT data in our patients with this new instrument., (© 2012 American College of Veterinary Ophthalmologists.)

Purpose: To describe the use of a digital single lens reflex (dSLR) camera adaptor for conducting posterior segment fluorescein angiography in canines., Methods: Ten beagle dogs free of ocular and systemic disease were used. All dogs received maropitant citrate (1.0 mg/kg SQ), diphenhydramine (2.0 mg/kg SQ), and topical 1% tropicamide 20 min prior to sedation using butorphanol (0.2 mg/kg IV). Standard color and red-free fundus images were obtained prior to the administration of 10% sodium fluorescein (20 mg/kg IV). Image acquisition was performed using a dSLR camera (Canon 7D), dSLR camera adaptor, camera lens (Canon 60 mm macro), and a 60D indirect ophthalmic lens, in addition to an accessory flash (Canon 580EXII). Two combinations of excitation and barrier filters were assessed (absorptive vs. interference). Imaging occurred at a rate of 1/s immediately following the fluorescein bolus for a total of 30 s and then at 1, 2, 3, 4, and 5 min., Results: Quality high resolution fluorescein angiographic images of the canine posterior segment were obtainable. All angiographic phases were identified and time sequences were recorded. Use of interference filters improved image contrast and transmission properties as compared to absorptive filters. No adverse events were noted., Conclusions: The described dSLR camera adaptor provides an alternative to existing posterior segment imaging systems capable of performing fluorescein angiography. High resolution image acquisition occurred at a fraction of the cost of established imaging systems., (© 2012 American College of Veterinary Ophthalmologists.)