CATARACT-SURGERY IN NANOPHTHALMIC EYES WI TH AXIAL LENGTH LESS-THAN 20.5 MM

Backround Aim of this study was to analyze the results of cataract sur gery in nanophthalmic eyes with axial length of less than 20.5 mm. Pat ients and Methods From 1991 to 1996 extracapsular cataract extraction with posterior chamber lens implantation was performed in 20 eyes of 1 9 patients (mean age 70.2 +/- 12.7 years, 4 male, 16 female) with axia l length of less than 20.5 mm. Mean preoperative visual acuity was 0.1 6+/-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 wer e collected prospectively with standardized ''Erlanger Augenblatter'' and the computer-aided automatized operation record system ''OPERA''. These data together with the biometrical data were analized in a retro lective manner. Results Preoperatively 6 of 20 eyes had angle closure situation, 7 of 20 eyes had undergone intraocular surgery previously ( 5 x iridotomy, Ix surgical iridectomy, 1 x filtration procedure). Pseu doexfoliation syndrome was present in 3 eyes. The posterior chamber le ns (mean refractive power 31.7+/-3.0 dpt, optic diameter 6.5 and 7.0 m m) was positioned 18 x intracapsular, 2 x into the sulcus and 1 x by s cleral fixation due to capsular rupture without vitreous loss. In 16 o f 20 eyes iris surgery was performed additionally, in one eye an anter ior sclerotomy was necessary. Intraoperatively ''vis a tergo'' ocurred in 10 eyes and anterior chamber hemorrhage in one eye. Visual acuity inproved 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 preoperativ ely calculated refraction. Postoperatively angle closure glaucoma deve loped in one eye, a ciliopseudophakic angle closure glaucoma and recur rent iris bombata in one eye. Reoperations included cyclokryokoagulati on in two eyes, pars plana vitrectomy in one eye and repeated Nd-YAG i ridotomies in one eye. Conclusion Regarding the special anatomic situa tion, the surgical procedure has to be planned individually, including the determination of sclera thickness, corneal diameter and lens volu me/eye volume ratio.