Quantitative Analysis of Anterior Capsule Opening after PMMA, Silicone and Acrylic Intraocular Lens Implantation

To quantify the periodic changes in the area of anterior capsule opening after cataract surgery and to compare any difference between polymethylmethacrylate (PMMA), silicone and soft acrylic IOLs, we prospectively studied 442 patients (465 eyes)who were operated from September 1997 to November 1999 at our hospital.All patients had standardized phacoemulsification, continuous curvilinear capsulorhexis, and intraocular lens implantation performed by the same surgeon.Patients were randomized into three groups based on the type of intraocular lens.The area of anterior capsule opening was quantitated using the Anterior Eye Segment Analysis System (EAS-1000), and examinations were performed at 1 week and 1, 3 and 6 months after surgery.The mean anterior capsular opening area at 1, 3 and 6 months postoperatively was smaller than that of 1 week in all 3 groups (P<.05)and the mean percentage of reduction in the PMMA and soft acrylic intraocular lens groups was significantly smaller than that in the silicone intraocular lens group at 1, 3 and 6 months after surgery (P<.05).In the silicone group, the contraction of the anterior capsule opening was greater than either PMMA or soft acrylic intraocular lens groups.Further studies will be needed for the evaluation of clinical application of silicone and soft acrylic intraocular lens.

Comparison of Anterior Capsule Opening after Silicone Intraocular Lens Implantation with and without Capsular Tension Ring

To evaluate the effect of capsular tension ring on prevention of capsular opening reduction induced by CCC in Phacoemulsification with silicone intraocular lens implantation, we prospectively studied 60 patients (60 eyes)who were operated from Sept, 1997 to Jun, 1998 at our hospital.All patients had standardized Phacoemulsification, continuous curvilinear capsulorhexis, and intraocular lens implantation performed by the same surgeon.Patients were randomized into two groups based on capsular tension ring insertion.We compared uncorrected visual acuity (UCVA), spherical equivalent (SE), astigmatism and the data obtained by the Anterior Eye Segment Analysis System (EAS-1000), anterior chamber depth, IOL tilting, decenteration, and anterior capsule opening area at 1 week and 1, 3, 6 months after surgery.Two groups showed a similar pattern of change of UCVA, SE and astigmatism. There are no statistical significances in comparison of anterior chamber depth and IOL decenteration in two groups, but IOL tilting of group II is greater than that of group I at 6 months after surgery.The mean anterior capsular opening area at 1, 3, 6 months postoperatively was smaller than that of 1 week in two groups, but no statistical significances were observed in group II (1, 3, 6 months, P = or > .05).The mean percentage reduction of group I was significantly smaller than that of group II at 3 and 6 months (P<.05)after surgery.Capsular tension ring might prevent a contraction of capsular opening and might enhance the stability of IOL.

Implantable Contact Lens to Correct High Myopia(Clinical Study with 24 Months Follow-up)

A ICL TM(STAAR Collamer Posterior chamber Implantable Contact Lens) lents ranging from -11D to -21.3D. And then we investigated the visualwas implanted in 12 eyes of 7 patients with preoperative spherical equivalents ranging from -11 D to -21.3 D. And then we investigated the visual acuity, mean endothelial cell loss, change of refractive error and postoperative complications.Average follow-up was 28.1 months. In the immediate postoperative days, all eyes had a significant increase in uncorrected visual acuity and the best corrected visual acuity was improved in 7 eyes(58.3%). Mean percent difference between preoperative and postoperative endothelial cell count was 3.22+/-0.05% . The mean preoperative spherical equivalent refraction was -15.65+/-2.78 D. At a mean follow-up of 1 month, mean spherical equivalent refraction was -1.67+/-0.72D, at a 6months, 12 months, 24 months, mean spherical equivalent refraction was each -1.56+/-0.72D, -1.63+/-0.68D, -1.73+/-0.76D. During follow-up days one eye developed an faint anterior subcapsular cataract but the patient remained symptom free. Other reported complication was transient increased intraocular pressure. Although the follow-up in our study was limited cases(12 eyes), from our experience, the posterior chamber implantable contact lens was efficacious and safe in the correction of high myopic refraction errors.

Diathermic Capsulotomy for Phacoemulsification in Hypermature Cataract

To evaluate the result of diathermic capsulotomy for phacoemulsification in hypermature intumescent cataracts, we retrospectively studied 34 patients(35 eyes) who were operated from January 1995 to February 1997. Central corneal endothelia cell counts were taken preoperatively and 2 months postoperatively by non-contact specular microscopy and endothelial cell loss(%) was calculated. The anterior capsular radial tear occurred in 24 eyes(68%), posterior capsular rupture occurred in 1 eye(2.9%) and the percentage of postoperative endothelial cell loss was 6.45(+/-7.27)%. The high rate of anterior capsular radialtear was due to altered mechanical integrity of the diathermic capsulotomy edge. But the thermal effect on the corneal endothelium was minute. Based on these findings, the diathermic capsulotomy for phacoemulsification in hypermature intumescent cataracts is very useful technique.