Cataract surgery in nanophthalmic eyes with an axial length of less than 20.5 mm

Abstract

Aim of this study was to analyze the results of cataract surgery in nanophthalmic eyes with axial length of less than 20.5 mm. From 1991 to 1996 extracapsular cataract extraction with posterior chamber lens implantation was performed in 20 eyes of 19 patients (mean age 70.2 +/- 12.7 years, 4 male, 16 female) with axial length of less than 20.5 mm. Mean preoperative visual acuity was 0.16 +/- 0.15, refractive error +5.1 +/- 3.8 dpt and intraocular pressure 18.7 +/- 10.3 mm Hg. The mean follow-up was 24.4 months. Patient data were collected prospectively with standardized "Erlanger Augenblätter" and the computer-aided automatized operation record system "OPERA". These data together with the biometrical data were analized in a retrolective manner. Preoperatively 6 of 20 eyes had angle closure situation, 7 of 20 eyes had undergone intraocular surgery previously (5 x iridotomy, 1 x surgical iridectomy, 1 x filtration procedure). Pseudoexfoliation syndrome was present in 3 eyes. The posterior chamber lens (mean refractive power 31.7 +/- 3.0 dpt, optic diameter 6.5 and 7.0 mm) was positioned 18 x intracapsular, 2 x into the sulcus and 1 x by scleral fixation due to capsular rupture without vitreous loss. In 16 of 20 eyes iris surgery was performed additionally, in one eye an anterior sclerotomy was necessary. Intraoperatively "vis a tergo" occurred in 10 eyes and anterior chamber hemorrhage in one eye. Visual acuity improved in 16 of 20 eyes. The mean visual acuity was 0.3 +/- 0.2. At the end of follow-up 13 eyes had an improvement of visual acuity. Mean intraocular pressure was 16.5 +/- 3.3 mm Hg, refractive error was +0.47 +/- 2.9 dpt and differed by -0.49 +/- 1.8 dpt from the preoperatively calculated refraction. Postoperatively angle closure glaucoma developed in one eye, a ciliopseudophakic angle closure glaucoma and recurrent iris bombata in one eye. Reoperations included cyclokryokoagulation in two eyes, pars plana vitrectomy in one eye and repeated Nd-YAG iridotomies in one eye. Regarding the special anatomic situation, the surgical procedure has to be planned individually, including the determination of sclera thickness, corneal diameter and lens volume/eye volume ratio.