Comparison of polymethylmethacrylate versus hydrophobic acrylic lenses for primary intraocular lens implantation in pediatric cataract surgery / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To compare the visual results and postoperative complications of polymethylmethacrylate(PMMA)and hydrophobic acrylic intraocular lenses(IOLs)in children who underwent cataract extraction with primary IOL implantation.<p>METHODS:This retrospective study included 117 eyes of 63 children with bilateral pediatric cataract undergoing cataract surgery and primary IOL implantation. The patients were divided into two groups, Group I included 58 eyes of 30 patients with PMMA IOLs; Group II included 59 eyes of 33 patients with hydrophobic acrylic IOLs. The clinical features, refraction errors, best corrected visual acuity(BCVA)and surgical complications were compared between two groups.<p>RESULTS:The mean age at the time of surgery was 5.8(2-12)y and mean follow up period was 40.5(6-196)mo. Postoperatively, BCVA was ≥0.5 in 80 eyes(68.4%)and this was comparable in two groups. Visual axis opacification was seen in 28 eyes(48.3%)in Group I and 16 eyes(27.1%)in Group II and this difference was statistically significant(<i>P</i>=0.018). Postoperative IOL dislocation and posterior synechia formation were also noted. When all postoperative complications were considered, there were significantly less complications in the acrylic IOL group than PMMA IOL group(<i>P</i>=0.020).<p>CONCLUSION: Pediatric cataract surgery with primary IOL implantation is a safe procedure. Hydrophobic acrylic IOLs may lead to less postoperative complications compared to PMMA IOLs.

Long-term results after primary intraocular lens implantation in children operated less than 2 years of age for congenital cataract.

Purpose: To study the long‑term outcome of cataract surgery with primary intraocular lens (IOL) in children <2 years. Materials and Methods: Retrospective analysis of bilateral cases that were operated before 2 years age for congenital cataract. All underwent primary posterior capsulotomy with anterior vitrectomy and primary IOL implantation. Only those with a follow‑up of at least 8 years were evaluated. Results: Twenty‑six eyes of 13 children with bilateral cataract met the inclusion criteria. Average age at surgery was 14.15 months with a mean follow‑up of 102 months. Average preoperative axial length (AL) was 19.93 mm. There was a refractive shift from a mean spherical equivalent of 1.64 D at 2 weeks after surgery to -1.42 D measured at last follow‑up. Twenty‑four eyes out of 26 (92%) achieved final visual acuity (VA) of 6/18 or more at last follow‑up with 19/26 (73%) having acuity of 6/12 or greater. Raised intraocular pressure was documented in one eye only. Average AL recorded at last follow‑up was 22.21 mm. Conclusion: Primary IOL implantation in children <2 years is a safe surgical procedure with excellent long‑term results. The myopic shift is well‑controlled and final VA achieved is reasonably good.

Laboratory analyses of two explanted hydrophobic acrylic intraocular lenses.

Two three‑piece hydrophobic acrylic intraocular lenses (IOLs) were explanted from two patients at 7 and 9 years, respectively, after implantation, because of poor fundus visualisation and/or a clinically significant decrease in visual acuity related to their opacified IOLs. In addition to light microscopy, scanning electron microscopy and energy dispersive X‑ray spectroscopy, confocal laser scanning microscopy was used for the first time to observe the explanted IOLs. The clinical aspect seemed to correspond to the phenomenon of surface light scattering, while laboratory analyses showed dense glistenings in the central layer of the IOL optic, which had no change next to the surface. Further studies on these phenomena are needed.

Comparison of Long-Term Results between One-piece and Three-piece Acrylate Intraocular Lens

PURPOSE: To compare the long-term clinical results of one-piece Acrysof(R) (SA60AT) hydrophobic acrylic intraocular lens (IOL) implantation compared with implantation of three-piece Acrysof(R) (MA60BM) hydrophobic acrylic IOL. METHODS: We retrospectively analyzed each 50 eyes of 50 patients underwent MA60BM or SA60AT IOL implantation and followed for at least 6 months. RESULTS: Final visual acuity of 0.5 or better was 38 eyes (76%) and 0.8 or better was 20 eyes (40%) in the SA60AT group. In the MA60BM group, it was 41 eyes (82%) and 23 eyes (46%) respectively. There were no significantly differences in predictability, intraocular pressure, endothelial cell density, astigmatism, and incidence of posterior capsule opacification between the two groups. Spherical equivalent at postoperative 1 week was -0.50+/-0.95D in SA60AT group and was -0.31+/-0.88D in MA60BM group (P=0.04). However, there was no significant difference between the two groups during follow up period. In MA60BM group, anterior chamber depth (P=0.02) and distance between iris and IOL (P=0.04) reduced significantly during the first postoperative month. CONCLUSIONS: Early postoperative axial displacement and changes in spherical equivalent can be occurred in MA60BM group. However there was no difference in long-term clinical results between SA60AT and MA60BM groups.

Adhesion and Morphologic Change of Lens Epithelial Cell According to Materials of Intraocular Lens

PURPOSE: We investigated the adhesion rate and morphologic change of lens epithelial cell (LEC) according to materials of intraocular lens (IOL). With the results, we estimated the appearance and characteristics of posterior capsular opacity after cataract extraction. METHODS: LECs were prepared from fresh bovine lens. Hydrophobic acylic IOLs such as Acrysof(R) and Sensar(R) and hydrophilic acrylic IOLs such as Corneal(R) were tested. On the days 2, 9 and 12 of LEC culture, we calculated the adhesion rate and observed the cellular morphologic changes. Immunostaining with alpha smooth muscle actin (SMA) was performed. RESULTS: Adhesion rate was higher in hydrophilic lens on the days 2 and 9 (p-value=0.029). Acrysof(R) had the lowest adhesion rate. LEC in hydrophobic IOL showed differentiation to myofibroblast that was strong positive for SMA. LEC in hydrophilic IOL preserved natural cellular morphology until the day 12. Immunostaining with SMA was nearly negative. CONCLUSIONS: Hydrophobic acrylate induced much differentiation from LEC into myofibroblast, but had low adhesion rate. Hydrophilic acrylate does not induce the differentiation, but has high adhesion rate.