[Cataract surgery in nanophthalmic eyes]

The aim of this study was to determine the prevalence of nanophthalmos among cataract patients and to evaluate intraoperative and postoperative complications in nanophthalmic eyes.

Medical and operating records of all 3287 patients who had undergone clear cornea phacoemulsification cataract surgery with foldable acrylic IOL implantation during a period of two years (January 2009 to December 2010) were retrospectively reviewed. Nanophthalmos was diagnosed according to a shorter axial length than 20 mm, a shallow anterior chamber, hyperopia and scleral thickness greater than 1.7 mm as determined by echography. Before surgery all patients received an intravenous 20 % mannitol solution.

From 3287 eyes, six eyes of four patients were identified as nanophthalmic with an axial length below 20 mm and a scleral thickness greater than 1.7 mm. The prevalence of nanophthalmos was 0.18 %. The average hyperopia was + 7.87 D (+ 6.0 to + 9.50). The mean axial length was 19.58 mm (18.94 to 20.00). The mean biometry calculation was 33.16 D (31.5 to 36.0). In all cases no complications were observed during the surgery. In two eyes a mild iritis was observed one day after surgery. During a follow-up of 3 months no further complications occurred.

Surgical manipulation in a narrow and crowded anterior chamber in nanophthalmic eyes with increased vitreous pressure is always a challenge and must be performed by an experienced surgeon. Preoperative examination of scleral thickness and preoperative administration of hyper-osmotic solution for reduction of vitreous pressure are very important to prevent unexpected complications. There was no need for a prophylactic surgical procedure in our patients.