An ultrasonograghic study of anatomical characteristic of nanophthalmos

Abstract

Objective To study the anatomical characteristic of nanophthalmos with ultrasonography and its clinical significance. Methods Forty-four nanophthalmic eyes (22 patients) and 200 normal eyes (100 persons) were included. A series of ocular parameters, including ocular axial length, angle between trabeculum and iris,thickness of lens and sclera.and vitreous cavity length were measured with ultrasound A-scan and ultrasound biomicroscopy. The refractive status was examined with dioptometry. Results The ocular axial length[(15. 95±0. 76)mm] and vitreous cavity length [(8. 48±0. 90)mm] were shorter, the lens [(4. 9±0. 53)mm] and sclera [(0. 917±0. 119)mm] were thicker in nanophthalmic eyes than those of normal eyes( P <0.01). The relative position of lens (0.312±0.09) was more forward, and the angle between trabeculum and iris (11. 41 ±7. 63 ) was narrower in nanophthalmic eyes, compared with normal eyes( P <0. 01). The hyperopia of nanophthalmic eyes was negatively correlated with the ocular axial length ( r = -0.806) and vitreous cavity length ( r = - 0. 663) ( P <0. 01). Conclusions Nanophthalmos was characterized by short ocular axial length, thick lens and sclera.and narrow anterior chamber angle. The thickness of sclera and the angle between trabeculum and iris measured with ultrasound biomicroscopy could provide a solid indication of the treatment to the complication of angle closure glaucoma. Key words: Ultrasonography; Microphthlmos