Ultrasound biomicroscopy of globes from young adult pigs

Abstract

Abstract Objective To determine anterior chamber ocular measurements of adult porcine globes without histologic fixation by use of ultrasound biomicroscopy scanning. Sample Population 25 porcine globes obtained at an abattoir. Procedure Globes were packed on ice for transport. In the laboratory, globes were trimmed, rinsed with antibiotic solution, secured on a single gauze-fold in a latex holder, then were ultrasonogrammed unreformed. Ultrasound biomicroscopy scanning was done, using a 50-MHz transducer, 17-mm cup, and 2% methyl cellulose. Results Average young adult pig external ocular measurements were: nasal-temporal corneal diameter, 16.61mm; superior-inferior corneal diameter, 14.00 mm; nasal-temporal globe diameter, 25.48 mm; superior-inferior globe diameter, 24.48 mm; and axial length 21.64 mm. Ultrasound biomicroscopy anterior chamber measurements were: iris sulcus, 30.45°; ciliary sulcus, 18.89°; central corneal thickness, 0.98 mm; corneal thickness at limbus, 1.19 mm; central iris thickness, 0.58 mm; iris tip to ciliary apex, 1.73 mm; iris tip to iris sulcus origin, 3.83 mm; iris tip to ciliary sulcus origin, 2.98 mm; anterior chamber depth from iris tip to cornea, 2.21 mm; central anterior chamber depth, 2.47 mm; ciliary process mid-thickness, 0.65 mm; ciliary process apex to origin of iris sulcus, 2.32 mm; ciliary process apex to origin of ciliary sulcus, 1.34 mm; zonular bundle diameter, 0.10 mm; and interzonular bundle space, 0.11 mm. Conclusions Anatomic anterior chamber measurements and relations in porcine globes can be used to describe trauma, confirm existence of lesions, and help explain theory. Clinical Relevance Ultrasound biomicroscopy is a clinical decision aid facilitating noninvasive anatomic or pathologic description without histologic fixation. (Am J Vet Res 1997;58:942–948)