Analyse der Gründe für Aphakie und Vergleich der Therapieresultate nach sekundärer intraokularer Linsenimplantation

Methods: In this retrospective study we analyse the reasons for aphakia in patients who underwent secondary intraocular lens implantation in the past 6 years. From 2002 till 2007 a total of 105 aphakic patients (110 eyes) were treated at the Universitäts- augenklinik Marburg either by secondary lens implantation or lens repositioning. Our collective included 72 men and 38 women with an average age of 63 (range 6 to 92 years). In order to quantify and compare the various surgical techniques we collected data concerning pre- and postoperative visual acuity and refraction, pre- and postoper-ative intraocular pressure, complication rates and postoperative patients’ assessment. Results: The most frequent reason for aphakia with a share of 62% (68 eyes) is the dislocation of the lens because of trauma (40%), idiopathic lens dislocation (34%), PEX-Syndrome (12%), Zonulolysis (6%) and Marfan’s syndrome (6%). With a share of 32% (35 eyes) the second most common reason for aphakia is an iatrogenic aphakia, a surgical consequence, for example an unsuccessful cataract surgery. Paediatric cata-ract is with a share of 6% (7 eyes) a rather rare reason for aphakia. 89% of all aphakic patients were treated with a secondary intraocular lens implantation. 11% underwent a lens repositioning. The most frequently used lens was a sutured posterior chamber lens (35%), followed by the retropupillar-invers implanted iris-fixated posterior chamber lens (32%) and the sulcus-fixated lens (22%). A change of trend could be observed: While the retropupillar-invers implanted iris-fixated lens increased percental and in absolute numbers until they were used in almost 60% of all interven-tions in 2007, there was a decrease in numbers for the sutured posterior chamber lens as well as the sulcus-fixated lens. With an average refraction-difference (postoperative refraction – target refraction) of - 0,41 dpt sulcus-fixated lens offers the most accurate results concerning postoperative refraction, closely followed by the iris-fixated lens with 0,42 dpt and the suture-fixated lens with - 0,59 dpt. In 28 out of the 97 eyes (29%) treated with lens implantation we observed a divergence from the target-refraction > 1 dpt. The biggest difference between pre-and postoperative cylindrical equivalent occurred in the lens-reposition-group with an average postoperative astigmatism of - 1,35. The 4 differences in the other groups were comparatively smaller: - 0,89 dpt for the iris-fixated lens, - 0,38 dpt for the suture-fixated lens and - 1,1 dpt for the sulcus-fixated lens. After implantation of the iris-fixated posterior chamber lens 71% of all patients showed an increase in visual acuity. In this same group we detected the highest increase in visual acuity of all lens types with an average of 0,16 (± 0,22) three months after sur-gery. With the sutured posterior chamber lens 63% of all patients achieved an increase in visual acuity. In the groups with the sulcus-fixated lens and the lens repositionings we detected an increase in 58% of all patients in each group. In 55 of the 110 operations there occurred no complications at all. Also most of the observed complications were minor and/or transient. The most common complication was deviation of the intraocular pressure and we also observed cases with pupil-distortion, lens dislocation and uneven descemet-membrane. With a total of only 25% complications the lens-repositioning is the method with the smallest complication rate. The statistic evaluation using a variance analysis showed no significant differences concerning postoperative visual acuity and refraction results between the four thera-peutic groups. Conclusions: This study indicates that all three lens types are effective and equivalent options for the treatment of aphakia. For the right choice of lens type preoperative oph-thalmologic findings should be taken into account. Repositioning and refixation of an intraocular lens is an equally safe and effective method for treatment of aphakia if the anatomic situation is sufficient.