D J Coleman1. 1. Department of Ophthalmology, Cornell University Medical College, New York 10021, USA.
Abstract
PURPOSE: This article describes an anatomic classification for the hypotonous eye and links this classification with approaches to the surgical treatment of this condition. The classification is based on very-high-resolution ultrasound scans and three-dimensional reconstruction of planar ultrasound scans. METHODS: Standard 10-MHz B-scans and very-high-resolution (40-60 MHz) scans were performed with a planar motor system using the immersion method. The anatomic changes in the hypotonous eye were classified and correlated with clinical and ultrasonographic findings at the time of therapeutic intervention and after resolution of the hypotonous condition. RESULTS: Hypotony is defined as low intraocular pressure most commonly due to ciliary body detachment or ciliary body dysfunction. With ciliary body detachment, three anatomically related causative types were identified: tractional hypotony, which has ultrasonographically demonstrable proliferative vitreociliopathy with membrane attachments between the ciliary body, iris, and formed vitreous; dehiscence hypotony, which has a modification in the scleral acoustic architecture consistent with a scleral break or wound dehiscence; and primary type hypotony, which has ciliary body detachment but no ultrasonographically demonstrable tractional component or scleral anatomic modification, but may have an iris scleral separation. CONCLUSIONS: Each type of ciliary body detachment hypotony may have a different management approach, so high-resolution ultrasound, particularly when shown with sequencing or three-dimensional displays to demonstrate the extent of detachment, can aid in the selection and implementation of appropriate therapy.
PURPOSE: This article describes an anatomic classification for the hypotonous eye and links this classification with approaches to the surgical treatment of this condition. The classification is based on very-high-resolution ultrasound scans and three-dimensional reconstruction of planar ultrasound scans. METHODS: Standard 10-MHz B-scans and very-high-resolution (40-60 MHz) scans were performed with a planar motor system using the immersion method. The anatomic changes in the hypotonous eye were classified and correlated with clinical and ultrasonographic findings at the time of therapeutic intervention and after resolution of the hypotonous condition. RESULTS:Hypotony is defined as low intraocular pressure most commonly due to ciliary body detachment or ciliary body dysfunction. With ciliary body detachment, three anatomically related causative types were identified: tractional hypotony, which has ultrasonographically demonstrable proliferative vitreociliopathy with membrane attachments between the ciliary body, iris, and formed vitreous; dehiscence hypotony, which has a modification in the scleral acoustic architecture consistent with a scleral break or wound dehiscence; and primary type hypotony, which has ciliary body detachment but no ultrasonographically demonstrable tractional component or scleral anatomic modification, but may have an iris scleral separation. CONCLUSIONS: Each type of ciliary body detachment hypotony may have a different management approach, so high-resolution ultrasound, particularly when shown with sequencing or three-dimensional displays to demonstrate the extent of detachment, can aid in the selection and implementation of appropriate therapy.