Taekjin Nam

Effects of prostaglandin-mediated and cholinergic-mediated miosis on morphology of the ciliary cleft region in dogs

OBJECTIVE To compare morphology of the ciliary cleft (CC) region in dogs after topical administration of latanoprost, pilocarpine, or a combination of latanoprost and pilocarpine. ANIMALS 6 Beagles. PROCEDURES A prospective 4-phase crossover study with washout periods was performed. Latanoprost (phase L), pilocarpine (phase P), pilocarpine followed by latanoprost (phase PL), and latanoprost followed by pilocarpine (phase LP) were administered to the right eye. Artificial tears were administered to the left eye (control eye). For each phase, pupil diameter and intraocular pressure (IOP) were measured and ultrasonographic biomicroscopy was performed 2 hours after topical treatment. Angle opening distance (AOD), ciliary cleft width (CCW), ciliary cleft length (CCL), and ciliary cleft area (CCA) were evaluated. RESULTS All treated eyes had marked miosis without significant differences in pupil diameter among phases. Significant IOP reductions were detected for all phases, except phase P. The AOD and CCA were significantly increased in all phases for treated eyes, compared with results for control eyes. The CCW was significantly increased in phases P, PL, and LP; CCL was significantly increased in phases PL and LP. Comparison of treated eyes among phases revealed that CCW differed significantly between phases L and P and between phases L and PL. CONCLUSIONS AND CLINICAL RELEVANCE Prostaglandin-mediated and cholinergic-mediated miosis caused variations in CC configurations. When latanoprost and pilocarpine were used in combination, the first drug administered determined the cleft morphology, which was not fully reversed by the second drug. The CC morphology did not fully explain IOP reductions.

Ultrasound biomicroscopy and tonometry in ophthalmologically normal pigeon eyes

OBJECTIVE To evaluate the feasibility of ultrasound biomicroscopy (UBM) and tonometry in pigeons and to provide biometric reference ranges for normal pigeon eyes. ANIMALS STUDIED Ten pigeons (Columba livia var. domestica) with ophthalmologically normal eyes. PROCEDURES Ophthalmic examinations, including slit-lamp biomicroscopy and tonometry, were performed to confirm that the eyes were normal. UBM was then performed on the left eye. On each obtained image, the ciliary cleft (CC) length, CC width, and CC area, and iridocorneal angle (ICA) were measured. RESULTS Richly vascularized iris was observed in all pigeon eyes. Mean intraocular pressure was 11.7 ± 1.6 mmHg, without any statistical difference between the left and right eyes. The UBM scanning procedure was well tolerated in all pigeons. Mean values of CC length, CC width, CC area, and ICA were 1.55 ± 0.17 mm, 0.36 ± 0.05 mm, 0.39 ± 0.04 mm2 , and 15.17 ± 1.06°, respectively. CONCLUSIONS Ultrasound biomicroscopy could be a useful diagnostic tool to evaluate anterior ocular segment of pigeons.