Scleral Fixation Re-examined by Ultrasound Biomicroscopy

Abstract

Objective: To assess postoperatively the position of the haptics of the scleral fixated posterior chamber intraocular lenses (IOLs), in order to improve precision in scleral fixation. Study Design: A number of 12 patients (16 IOLs) were studied postoperatively by ultrasound biomicroscopy (UBM). The STC-6 straight needle was used for scleral fixation, with different techniques. In addition, 8 aphakic eyes selected for secondary implantation were studied. Setting: University Eye Clinic, Verona, Italy. Main Outcome Measures: The position of the loops in the suture of the scleral fixation was determined. This position was related to the surgical technique and to the distance between the emergence of the sutures and the limbus. The status of the posterior chamber was studied in aphakic eyes. Results: Out of the 32 loops, 24 were located in the pars plana, 6 were located in the ciliary sulcus, and 2 were located in the iris root. After ab interno fixation (9 eyes), with a suture to limbus distance of 2–3 mm, all but 2 loops were posterior to the ciliary sulcus. After ab externo fixation (7 eyes), with a suture to limbus distance of 1.5–2 mm, 6 loops were in the pars plana, 6 were in the ciliary sulcus and 2 loops were against the iris root. Most aphakic eyes showed some anatomical impairment of the posterior chamber. One eye showed ciliary body detachment. Conclusions: Suture to limbus distances of about 1 mm should be adopted for scleral fixation. Reversed fornix based scleral flaps could improve precision. However, we must emphasize that posterior synechiae or ciliary processes may obstruct the access to ciliary sulcus in aphakic eyes. The UBM study is very useful in eyes selected for secondary implantation.