OCULAR COMPLICATIONS AND A NEW SURGICAL APPROACH TO LENS DISLOCATION IN HOMOCYSTINURIA DUE TO CYSTATHIONINE-BETA-SYNTHETASE DEFICIENCY

The ocular findings in patients with homocystinuria due to cystathioni ne-beta-synthetase (CBS) deficiency are reviewed and a new approach to lens surgery is presented. Lens surgery in CBS deficiency was reporte d to be accompanied by a high risk of secondary complications like vit real prolapse and retinal detachment. So far an operative procedure fo r these patients that allows a complete preservation of the anterior v itreous cortex, the posterior lens capsule and an implantation of an a rtificial lens is not established. A minimal invasive method of lens s urgery was developed in vitro and applied in the case of a 10-year-old patient with an uncorrectable refractive situation due to progressed lens dislocation. Principle steps of the evolved operative procedure a re (1) visco-elastic stabilization of the anterior chamber: (2) small (1.5 mm) peripheral capsulorhexis: (3) manual endocapsular aspiration of lens material and removal of lens epithelium: (4) ab externo introd uction of a transcleral fixation suture: (5) positioning of the haptic into the ciliary sulcus in the inferior position: (6) resection of th e anterior lens capsule: and (7) positioning of the second haptic into the ciliary sulcus. The first patient created according to this metho d presented a stable position of the pseudophakos during the follow up of 1 year. Visual acuity improved from a level of 20/200 (O.D.) and 1 0/200 (O.S.) to 18/20 in both eyes. The surgical procedure presented i n this report seems to be useful for dealing with dislocated lenses du e to zonular deficiency in patients with CBS deficiency and hopefully with Marfan disease. It allows a minimal invasive removal of the lens, a complete preservation of the anterior vitreous cortex and at the sa me time a stable fi?ration of an artificial intraocular lens.