Management of late-onset flocculent after-cataract with capsular bag lavage and posterior continuous curvilinear capsulorhexis

We describe our technique for the management of late-onset liquefied after-cataract (LAC) to ensure long-term visual axis clarity. The densely adherent anterior capsular rim over the intraocular lens (IOL) optic was released with the help of microvitreoretinal blade, and multiple relaxing radial incisions were made on the capsular rim to facilitate easy access to the capsular bag. A thorough capsular bag lavage was performed with the help of bimanual irrigation-aspiration. Posterior continuous curvilinear capsulorhexis (PCCC) was performed after complete aspiration of fluid after-cataract to prevent recurrence. This technique was successfully performed in 14 cases. Postoperatively, IOL was stable and an uncorrected distance visual acuity of >20/32 was achieved in all cases. No recurrence was observed in any case over a follow-up of 1 year. Our technique of capsular bag lavage with PCCC is safe and effective for the management of LAC with optimal visual and anatomical outcomes.

The proliferative inhibition and apoptosis promotion of Smac on human lens epithelial cells / 中华实验眼科杂志

Background Posterior capsular opacification (PCO) is a primary complication after extracapsular cataract extraction.The mechanism of PCO is associated with proliferation,migration and epithelialmesenchymal transition (EMT) of human lens epithelial cells (LECs).To explore the target treatment of PCO is very important.Objective This study was to investigate the biological effects of second mitochondria-derived activator of caspases (Smac) on the proliferation and apoptosis of LECs.Methods Human LECs line (HLE-B3) and Smac-overexpressed LECs line were cultured,and the cells were transfected using small interfering RNA (siRNA)-Smac3 plasmid with green fluorescent protein (GFP) for 24 hours.Different concentration of transforming growth factor-β2 (TGF-β2) (5,10,20 and 50 μg/ml) or 200 μmol/L H2O2 were added respectively into the culture medium to establish PCO model and oxidative stress model.Cell counting kit-8 (CCK-8) assay was used to compare the cell proliferative activity among PBS group,TGF-β2 group and Smac-hyperexpression +TGF-β2 group.Flow cytometry was used to evaluate the apoptotic rate of the PBS group,H2 O2 group and siRNA-Smac+H2 O2 group.The expressions of Smac,caspase-3 and proliferating cell nuclear antigen (PCNA) mRNA and their proteins in the cells were detected by real-time quantitative PCR (RT-PCR) and Western blot.Results The GFP+ cells were≥ 80％ 12 hours after siRNA-Smac3 transfection,with the optimal plasmid of siRNA-Smac3.GFP+ cell rate was (72.32 ± 2.31)％ in the siRNA-Smac3 transfection group,which was significantly higher than that in the blank plasmid group ([4.91 ±0.24] ％) (t=116.342,P＜0.001).The relevant expression levels of Smac was 35.21 ±4.11 in the Smachyperexpression group,and that in the blank plasmid group was 15.24±2.48,with a significant difference between them (t =215.47,P＜0.05).The cell viability of 20 ng/ml TGF-β2 affected PBS group,TGF-β2 group and Smachyperepression+TGF-β2 group was (98.4 ± 1.7) ％,(98.9 ± 0.1) ％ and (64.2 ± 3.1) ％,and the cell viability of Smac-hyperepression+TGF-β2 group was significantly lower in the Smac-hyperepression+TGF-β2 group than that in the TGF-β2 group (P＜0.05).The apoptotic rate in the PBS group,H2 O2 group and siRNA-Smac+H2 O2 group were (2.9 ± 1.2) ％,(45.1 ±4.5) ％ and (27.5 ± 1.8) ％,and the apoptotic rate was evidently lower in the siRNA-Smac +H2O2 group than that in the H2O2 group (P＜0.05).RT-PCR results showed that the expression levels of caspase-3 mRNA in PBS group,H2 O2 group and siRNA-Smac + H2 O2 group were 0.321 ± 0.103,0.715 ± 0.112 and 0.479 ±0.209,respectively.Compared with the H2 O2 group,the relative expression level of caspase-3 mRNA in siRNA-Smac+ H2O2 group was significantly decreased,the difference was statistically significant (P＜ 0.05).The PCNA mRNA expression levels in PBS group,TGF-β2 group and Smac-hyperepression+TGF-β2 group were 0.299±0.013,0.645± 0.102 and 0.490±0.209,respectively.Western blot results showed that the relative expression of caspase-3 protein in siRNA-Smac+H2O2 group and H2O2 group was 0.712±0.012 and 0.973±0.051,with significant difference between the two groups (t =132.52,P＜0.05).The relative expression of PCNA protein in Smac-hyperepression+TGF-β2 group was 0.782±0.212,which was lower than 1.126±0.251 in the TGF-β2 group (P＜0.05).Conclusions Smac may prevent and treat PCO by inhibiting the proliferation and promoting apoptosis of human LECs.

The Influence of Vitrectomy of Nd:YAG Laser Posterior Capsulotomy

PURPOSE: This study aimed to investigate factors that cause after-cataract such as diabetes, intravitreal gas injection during vitrectomy, and other factors in relation to the vitrectomy. METHODS: The relationship between the vitrectomy and the frequency of Nd:YAG laser posterior capsulotomy was investigated in a sample of 947 monitored patients' eyes that underwent cataract surgery. The patients' eyes were classified into Group 1, which comprised 715 patients' eyes that underwent cataract surgery only, Group 2, which comprised 152 eyes that underwent both vitrectomy and cataract surgery at the same time, and Group 3, which comprised 80 eyes that underwent cataract surgery after vitrectomy. The age, gender, diabetes status, gases injected during the vitrectomy, and other factors were investigated. RESULTS: It was found that 50 eyes (6.99%) in Group 1 received the posterior capsulotomy, 28 eyes (18.4%) had the procedure in Group 2, and 16 eyes (20.00%) had the procedure in Group 3, respectively. In Group 1, 21 eyes (8.86%) that received the posterior capsulotomy were from diabetic patients, 20 eyes (19.8%) were diabetic in Group 2, and 10 eyes (21.73%) were diabetic in Group 3. In Group 1, 29 eyes (6.06%) were from non-diabetics that received posterior capsulotomy, 8 eyes (15.68%) were from non-diabetic patients in Group 2, and 6 eyes (17.64%) were from non-diabetic patients in Group 3. In the group that had vitrectomy with gas injection, 6 eyes (25%) received the posterior capsulotomy in Group 2, and 10 eyes (24.39%) had the procedure in Group 3, respectively, while those in the group that had vitrectomy without gas injection included 22 eyes (17.46%) in Group 2 and 6 eyes (15.38%) in Group 3. CONCLUSIONS: The Nd:YAG laser posterior capsulotomy was more frequently applied to patients who underwent vitrectomy, younger patients, diabetes patients, and patients who had vitrectomy with gas injection.

The Influence of Vitrectomy of Nd:YAG Laser Posterior Capsulotomy

PURPOSE: This study aimed to investigate factors that cause after-cataract such as diabetes, intravitreal gas injection during vitrectomy, and other factors in relation to the vitrectomy. METHODS: The relationship between the vitrectomy and the frequency of Nd:YAG laser posterior capsulotomy was investigated in a sample of 947 monitored patients' eyes that underwent cataract surgery. The patients' eyes were classified into Group 1, which comprised 715 patients' eyes that underwent cataract surgery only, Group 2, which comprised 152 eyes that underwent both vitrectomy and cataract surgery at the same time, and Group 3, which comprised 80 eyes that underwent cataract surgery after vitrectomy. The age, gender, diabetes status, gases injected during the vitrectomy, and other factors were investigated. RESULTS: It was found that 50 eyes (6.99%) in Group 1 received the posterior capsulotomy, 28 eyes (18.4%) had the procedure in Group 2, and 16 eyes (20.00%) had the procedure in Group 3, respectively. In Group 1, 21 eyes (8.86%) that received the posterior capsulotomy were from diabetic patients, 20 eyes (19.8%) were diabetic in Group 2, and 10 eyes (21.73%) were diabetic in Group 3. In Group 1, 29 eyes (6.06%) were from non-diabetics that received posterior capsulotomy, 8 eyes (15.68%) were from non-diabetic patients in Group 2, and 6 eyes (17.64%) were from non-diabetic patients in Group 3. In the group that had vitrectomy with gas injection, 6 eyes (25%) received the posterior capsulotomy in Group 2, and 10 eyes (24.39%) had the procedure in Group 3, respectively, while those in the group that had vitrectomy without gas injection included 22 eyes (17.46%) in Group 2 and 6 eyes (15.38%) in Group 3. CONCLUSIONS: The Nd:YAG laser posterior capsulotomy was more frequently applied to patients who underwent vitrectomy, younger patients, diabetes patients, and patients who had vitrectomy with gas injection.

Nd-YAG laser damage affects the optical properties of intraocular lens / 中国组织工程研究

BACKGROUND:Posterior capsulotomy with Nd-YAG laser is the main method in clinic for the treatment of after-cataract, but it often damages the intraocular lens during the treatment. OBJECTIVE:To research the effect of Nd-YAG laser damage on the intraocular lens optical properties based on the laboratory testing. METHODS:Ten hydrophobic acrylic intraocular lenses were col ected as the test samples, and then Nd-YAG laser with the pulse energy of 5.0 mJ was used for 50 single-pulse laser shooting on the center of a circle with the diameter of 3 mm on the back surface of each sample. The shapes of the damaged area on the samples were observed under scanning electron microscope after laser shooting. Optical analyzer was used to test the average optical power and optical power distribution. RESUTLS AND CONCLUSION:The intraocular lenses were observed under scanning electron microscope under 40 times and 1 000 times enlargement and showed that there was circle-like depression with the diameter about 50μm on the back surface of the intraocular lenses, and there was protruding around the depression. Intraocular lens optical analyzer test results showed that there was no significant change in the average optical power of intraocular lenses after laser damage, but the optical power distribution was changed significantly. In the center of the circle with the diameter of 3 mm, the optical power showed annular distribution radiating to the surrounding tissue with the center of circle-like depression area. The Nd-YAG laser damage has less effect on the optical power, but has great effect on the optical power distribution of intraocular lenses.

Effects of Lutein on the Growth and Migration of Bovine Lens Epithelial Cells In Vitro / 华中科技大学学报（医学）（英德文版）

The effects of lutein on the growth and migration of bovine lens epithelial cells (BLECs) in vitro were observed in an attempt to find a drug that can prevent after-cataract. BLECs were cultured in vitro and different concentrations of lutein were added to the BLECs cultures of the second and third generations. The effects of lutein on the proliferation of BLECs in vitro were examined by the MTT method, and the migration of BLECs was evaluated by a scratch wound assay. The results showed that: (1) Lutein at concentrations of 1 to 16μmol/L could inhibit the proliferation of BLECs in a dose-and time-dependent manner (P<0.01); (2) The migration of BLECs was evaluated by wound healing rate. As compared with the control group, the wound healing rate in the experimental groups was decreased from 0.672±0.164 to -0.234±0.144 and -0.597±0.063 (P<0.01) at 1 and 2μmol/L lutein, respectively. It was concluded that lutein at concentration of ≥1μmol/L inhibited the proliferation and migration of BLECs in vitro. Lutein may become an effective drug to prevent after-cataract.

Change of Pupil Diameter after Cataract Surgery or After-Cataract Surgery

PURPOSE: To investigate the change of pupil diameter following cataract surgery or after-cataract surgery and the dependence of this change on the opacity at photopic and scotopic adaptation. METHODS: Thirty-five eyes with cataract and 32 eyes with after-cataract were evaluated prospectively. The pupil diameter was measured at 220 lux (photopic) and 0.05 lux (scotopic) using a pupillometer. Cataract patients were examined preoperatively, and at 1 week and 2 months postoperatively, and after-cataract patients were examined preoperatively, and at 1 week postoperatively. The lens opacity was classified as opacity degree and the after-cataract was divided into pearl and fibrosis type. RESULTS: Pupil diameter of cataract patients was reduced after surgery at photopic and scotopic adaptation (p<0.05). The pupil diameter of eyes with severe opacity degree was 4.3 +/- 1.1 mm and 5.0 +/- 1.1 mm at photopic and scotopic adaptation, respectively, and was larger than eyes with mild opacity degree (3.9 +/- 1.1 mm and 4.5 +/- 1.1 mm, respectively, p<0.05). At photopic and scotopic adaptation, pupil diameter of after-cataract patients was reduced by Nd: Yag laser (p<0.05). The pupil diameter of eyes with fibrosis type, 4.6 +/- 1.0 mm, was significantly smaller than that of eyes with pearls type (5.1 +/- 1.1 mm, p<0.05). CONCLUSIONS: The pupil diameter of eyes with severe opacity degree was larger that of eyes with mild opacity degree. In after-cataract patients, pupil diameter was significant different depending on opacification type at scotopic adaptation and it was reduced after Nd: Yag laser.

Transdifferentiation of Cultured Bovine Lens Epithelial Cells into Myofibroblast-like Cells by Serum Modulation

An after-cataract is caused by the proliferation of residual cells over the equator of the lens. These cells subsequently migrate to the posterior lens capsule, where they undergo aberrant differentiation into fiber-like cells or transdifferentiation into fibroblast-like cells. To study the precise molecular mechanisms of transdifferentiation, an attempt was made to establish an in vitro system, in which the lens epithelial cells (LECs) of the pre-equatorial zone could be transdifferentiated into fibroblast-like cells. The required conditions for culturing the LECs were identified as consisting of four phases; intact bovine explants, explant-cultured, serum-modulated and additionally modulated LECs. The LECs of each phase were compared by examining changes in the expression of the epithelial-mesenchymal transition (EMT) -related genes and changes in cellular morphology and adhesion. The explants that were cultured in a medium containing 10% fetal bovine serum (FBS) for 2 weeks, showed changes in the expression of the EMT-related genes, although the other explant-cultured cells maintained an epithelial morphology. To introduce a transition into mesenchymal cells, the explant cultures were subcultured in a medium containing 20% FBS for six passages. These cells displayed an elongated morphology and were able to grow and migrate in a similar way to fibroblast cells. The expression of the EMT-related genes, such as, extracellular matrix proteins and integrins, was altered. This was similar to the alteration of the 3-dimensional collagen gels model previously reported. During a further process of EMT by additional serum modulation, the inhibitory effect of disintegrin on cell adhesion was gradually decreased, integrin expression was differentially regulated and alpha-smooth muscle actin was post-translationally modified from the point of passage number six. Overall, it can be concluded that terminal transdifferentiation accompanies changes in the cytoskeletal proteins and cell surface molecules. These are modulated in systematic patterns of post-transcriptional and post-translational regulation and patterns of gene regulation, by the synergic effects of several transforming factors contained in serum. Therefore, posterior capsular opacification may also be accompanied by this molecular mechanism.

Clinical Results of Primary Posterior Continuous Curvilinear Capsulorhexis

PURPOSE: To evaluate the outcome of posterior continuous curvilinear capsulorhexis (PCCC) performed simultaneously with cataract surgery to inhibit after-cataract. METHODS: Among patients who underwent phacoemulsification and posterior chamber intraocular lens implantation from December 1999 through December 2001, we had followed on 94 eyes of 80 patients who underwent PCCC intraoperatively and 100 eyes in 92 patients without PCCC as control group. Both groups were divided into 4 categories: nonproliferative diabetic retinopathy(NPDR); uveitis; below 60 years without ocular and systemic disease; over 60 years without ocular and systemic disease. Preoperative and postoperative visual acuity and complications were analyzed from 6 months to 12 months. RESULTS: There was statistically no difference in the best corrected visual acuity at 6 months between PCCC and control group in all categories. Transient increase in the intraocular pressure was noted in 5 eyes (5%) of PCCC group and 3 eyes (3%) in control group. Vitreous prolapse into anterior chamber was found in 2 eyes (2%) of PCCC group. Cystoid macular edema was found in only 1 eye (1%) in NPDR patients of PCCC group. Progression of diabetic retinopathy was found in 1 eye (5.6%) and 3 eyes (12.5%) in each group respectively. There was no statistically significant difference in progression of diabetic retinopathy after surgery between the two groups. CONCLUSIONS: Primary PCCC is a safe procedure to perform in patient who has a predisposition to after-cataract.

The Effect of Steroid and other Immunosuppressants on the Cataract and after-Cataract after Renal Transplantation

PURPOSE: To evaluate the effect of systemic steroid and other immunosuppressants on the development of cataract and after-cataract in renal transplant patients. METHODS: We compared fourteen patients (22 eyes) who had undergone operation by one surgeon for cataract after renal transplnatation since 1991 and their follow-up period after cataract surgery was over 6months with the group that didn't have cataract after renal transplantation and the group that had cataract without systemic disease on the clinical aspect of cataract and after-cataract and also relationship with use of systemic steroid and immunosupressants. RESULTS: Most patients who underwent renal transplantation had posterior subcapsular opacity (81%) and their mean daily steroid dosage was statistically significantly higher than that of patients who didn't have cataract after renal transplantation(p<0.05). However, daily cyclosporin dosage and the use of azathioprine didn't have difference between the two groups. Additionally, the incidence and onset of after-cataract following cataract surgery had no statistically significant difference or correlations with daily steroid dosage(r=0.002) and daily cyclosporin dosage(r=0.16) or the use of azathioprine. CONCLUSIONS: Careful control of steroid dosage and early combination therapy with other immunosuppressants are considered to prevent the development of cataract in renal transplant patients. Further research on the effect of immunosupressants for after-cataract will be helpful to maintatin good visual outcome after cataract surgery.

The Effect of Lens Nucleus and Cortex Material on Lens Epithelial Cell Culture through In vitro Capsular Bag Model

PURPOSE: This study attempts to evaluate the effect of lens cortex and nucleus remnants on posterior capsular opacification with method of the cell culture according to in vitro capsular bag model. METHODS: After bovine lens were isolated, we performed continuous curvilinear capsulorhexis and hydrodissectioin of the lens fiber mass. At this stage a tension ring was implanted and then the preparations placed in organ culture for up to 6 weeks. Lens cortex and nucleus material was added at the culture media in group 2, 3, 4, 5, 6 with amount of 1/16, 1/32, 1/64, 1/96, 1/128 of one lens volume. Group 1 was control group that was not added lens materials. Cell coverage of the posterior lens capsule was recorded and the capsules were examined, both pre-and post-coverage, for proliferative activity. RESULTS: After a lag period outgrowth was observed across the posterior capsule. The proliferative activity was greater at the groups that were added more amount of the lens cortex and nucleus material. CONCLUSIONS: it is important that we should not remain any lens cortex material remnant at cataract surgery.

Effect of Diabetes on the Developmental Duration of after-cataract in Pseudophakic Eyes with PMMA or Silicone IOL

PURPOSE: We studied the effect of the duration of diabetes or the severity of diabetic retinopathy on the development posterior capsular opacity in patients with PMMA or silicone intraocular lens (IOL) implan-tation following continuos capsulorhexis and phacoemulsification. METHODS: 41 eyes of diabetic patients (DM group) and 74 eyes of non-diabetic patients (control group) who had undergone Nd-YAG capsulotomy from January 1997 to May 2000 were included. RESULTS: The average interval from cataract surgery to Nd-YAG capsulotomy was 36.3+/-14.1 months with PMMA IOL and 25.3+/-11.8 months with silicone IOL in DM group (p<0.05). In control group, it was 38.0+/-15.1 months with PMMA IOL and 23.4+/-11.8 months with silicone IOL (p<0.05). There was no difference between DM and control groups. The severity of DM retinopathy did not influence the duration from cataract operation to posterior capsulotomy in DM group. Among the patients with diabeters for 10 years or longer, the mean interval from cataract operation to capsulotomy was longer in PMMA IOL group compared with silicone IOL group (P<0.05). CONCLUSION: Diabetics with PMMA IOL may maintain good vision for longer duration without posterior capsulotomy than those with silicone IOL. The silicone IOL group of more than 10-year DM duration needed posterior capsulotomy earlier than PMMA IOL group or the silicone IOL group of less than 10-year DM duration.

A Study of Factors Influencing After Cataract Development

PURPOSE: This study was performed in order to elucidate how the patient s age at cataract operation, coexisting systemic or other ocular diseases, cataract operation methods, and implanted intraocular lenses(IOLs) are associated with the after-cataract development. METHODS: The sixty-eight patients (87 eyes) which had undergone Nd-YAG capsulotomy at the Kangnam St. Mary s Hospital were studied with chart review retrospectively. All the cases had phacoemulsification, continous curvilinear capsulorhexis(CCC), and posterior chamber IOL implantation in the capsular bag. RESULTS: With regard to patient s age factor at cataract operation, the older patient, the more slowly did after-cataract develop. There is less development of after-cataracts that have no contact between anterior capsulectomy site and posterior capsule (36 eyes,41%) than have any contact (51 eyes, 59%). After-cataracts could be classified into Elschnig pearl type (51 eyes, 59%) and fibrous type (36 eyes, 41%), and fibrous type is especially few in those having no contact between anterior capsulectomy site and posterior capsule (P=0.0303). Foldable IOLs (including silicone, acrylic) have more fibrous type after-cataract (16 eyes of 29 eyes), on the contrary, polymethyl methacrylate(PMMA) IOLs have more Elschnig pearl type after-cataract. CONCLUSION: Through this study, we understand that patient s age and contact between anterior capsulectomy site and posterior capsule are the factors which can influence after-cataract development and type. However, there is no statistically significant difference between IOL and after-cataract type (P=0.0647).

Visual Prognosis and the Development of After-cataract following Cataract Surgery in Atopic Dermatitis

PURPOSE: To investigate the visual prognosis, the interval, and the rate of development of after-cataract following cataract surgery in atopic dermatitis. METHODS: Twenty eyes of 13 patients diagnosed as cataract associated with atopic dermatitis were operated between January, 1994 and January, 2000. Visual acuity, postoperative inflammatory reaction, the interval, and the rate of development of after-cataract were investigated and compared with the cataract cases without atopic dermatitis. RESULTS: The average preoperative best corrected visual acuity of 20 eyes was 0.23+/-0.22. The average postoperative best corrected visual acuity at 1, 2, 7, and 12 months after surgery were 0.78+/-0.23, 0.83+/-0.16, 0.78+/-0.23, 0.83+/-0.26, respectively. These values showed no significant difference compared to the postoperative visual acuity of the cataract cases without atopic dermatitis. Aqueous flares measured with laser flare meter were 15.09+/-9.20, 11.15+/-4.68, and 7.38+/-0.75 photon counts/millisecond at 10 days, 1, and 2 months after surgery, which did not seem to influence the final visual acuity and the development of after-cataract (p>0.05). Among the 20 eyes, 66.67% finally developed after-cataract and the average time interval of the development of after-cataract was 11.25+/-4.22 months. CONCLUSIONS: Visual prognosis following cataract surgery in atopic dermatitis is good, while after-cataract seems to develop more frequently and earlier compared to the cases without atopic dermatitis.

After-Cataract Following Pars Plana Lensectomy and PCL Implantation

We evaluated after-cataract, capsular opacification, following combined lens removal with phacoemulsification or pars plana lensectomy, pars plana vitrectomy and primary or secondary IOL implantation on 34 eyes followed up more than 3 years.For the lens removal 23 eyes had pars plana lensectomy ad 11 eyes phacoemulsification. Nd-YAG capsulotomy is needed on 8/34 eyes(25.5%). Nd-YAG capsulotomy was performed on 3/23 eyes(13%) of pars plana lensectomy and on 5/11 eyes(45.5%) of phacoemulsification. Nd-YAG capsulotomy was performed to 7/22 eyes(31.8%) of primary IOL implantation and 1/12 eyes(8.3%) of secondary IOL implantation. Most patients had systemic vascular disease such as diabetes or hypertension.In conclusion, combined pars plana lensectomy, pars plana vitrectomy and secondary IOL implantation was the least incidence of after-cataract and side effects, so this procedure was thought to be recommended for vitreoretinal surgery.

The Effect of Hydrophilic Treatment of PMMA using Hydrolysis on Cell Attachment and Light Transmission in Vitro(I)

Polymethyl-methacrylate(PMMA) has been used for a proper material of intraocular lens(IOL) but it can induce cyanopsia in psedophakia due to deficiency of light blockage, and corneal endothelial damage or deposition of inflammatory cells due to hydrophobia. Therefore, yellow IOL or heparin surface modified PMMA(HSM-PMMA) IOL was developed to prevent above problems, respectively. In this study, PMMAs were hydrolyzed with a 1:1 mixture of isopropranol and NaOH for 0hour(PMMA-0), 2 hours(PMMA-1), and 4hours(PMMA-2). The effect of hydrolysis treatment was evaluated by measurement of water contact angle and the optical properties was measured using spectrometer as well as cell attachment was examined by inverted light microscope using Wolters cytology method. Cell attachment, 5x104 of RAW264.7(mouse fibrosarcoma cell line) or L929(mouse macrophage) were layered on each PMMA for 12 hours and incubated for 3 days or 7 days. Hydrolysis treatment made PMMA surface hydrophilic ad opaque in time course manner. The attachment of both types of RAW264.7 and L929 cells on the PMMA-1 or PMMA-2 was markedly reduced than that of PMMA-0. The difference was statistically significant(P<0.05). And there was also statistically significant difference between PMMA-1 and PMMA-2(P<0.05). With these results it was found that hydrolysis method made PMMA surface hydrophilic and decreased the attachment of inflammatory cells as well as decreased light transmission like normal human lens. Therefore, this method would be one of proper surface modifications of PMMA.

The Effect of Hydrophilic Treatment of PMMA Material Using Hydrolysis on Cell Attachment in Vivo (II)

PMMA(polymethyl Methacrylate) introcular lens(IOL) has been designed for making surface hydrophobic. Hydrophilic IOL has advantages such as less damage of corneal endothelium and less attachment of inflammatory cells on the IOL surface especially in case of uveitis or diabetes mellitus. Therefore, hydrophilic IOL is regarded as a biocompatible IOL. In this study, we made PMMAs hydrophilic using hydrolysis (described in The Effect of Hydrophilic Treatment of PMMA using Hydrolysis on Light Transmission and Cell Attachment in Vitro (I)). The number of PMMA treated in each condition was twelve and each PMMA has been implanted into rat peritoneal space. These PMMAs were examined with inverted light microscope and scanning electron microscope 3 days and 7-14 days after implantation. The number of cell attachment on pMMA-1 or PMMA-2 was about 1/5 of that on PMMA-0 and the difference was statistically significant (p<0.05). There was no statistically significant difference of cell attachment between PMMA-1 and PMMA-2. The cells on PMMA-0 showed prominent cytoplasmic processes, while those on PMMA-1 or PMMA-2 showed little processes. The majority of the surface PMMA-0 was covered with membrane light sheet. Therefore, it was found that treatment of PMMA with Isopropranol and NaOH was useful in making PMMA dydrophilic and decreasing the cell attachment on PMMA in vivo.

Development of After-cataract in Pseudophakic Eyes with Silicone or PMMA Intraocular Lens

Foldable intraocular lenses(IOLs) arebeing used and wide spread with some advantages such asn little surgically induced astigmatism and rapid visual rehabilitation, but the effect of foldable IOLs on long-term safety and the formation of after-cataract was not understood clearly yet. 48 patients(54 eyes) which underwent Nd-YAG capsulotomy from 1995 to 1997 at the Kangnam St. Mary`s Hostpital were studied. All the cases had been operated by one operator(Joo) with the same technique except for incision method. The average interval from cataract surgery to Nd-YAG capsulotomy was 31 months in PMMA group and 15 months in silicone group. This difference between the two groups was statistically significant(P=0.0002). The ratio of Elschnig pearl type to fibrosis type in after-c attract was 16:6 in PMMA group and 13:18 in silicone group. The average of the total energy used in Nd-YAG laser capsulotomy was 256mJ in PMMA group and 309mJ in silicone group. However, damages caused by YAG laser were severer and more common on the silicone IOLs than on the PMMA IOLs. Silicone IOL induces after-cataract faster than PMMA IOL and the major type of after-cataract in pseudophakia with silicone IOL is fibrosis.

Ultrastructure of Transformed Lens Epithelial Cells in Anterior Subcapsular Cataractous Lens

Degeneration and transformation of lens epithelial cells (LECs) have been regarded as major causes of cataract and after-cataract. So behaviors of LECs have been studied in order to prevent some kinds of cataract and after-cataract, mainly in vitro. This study identified in vivo that human LECs beneath the anterior capsule were transformed in anterior polar type of cataract. Normal LECs showed positive staining for both cytokeratin and virnentin, while transformed LECs in the anterior polar type of cataractous lens were positive for vimentin only. Additionally, these transformed LECs seern to be fibrocytes without cellular junctions, are vertically or obliquely oriented, and spindle-shaped. These cells were embedded within 8 fibrillar meshwork rnass secreted by themselves. With this result it was found that LECs could be transformed into fibroblat like cells and this transformation of LECs were observed in anterior polar type of cataractous lens.

Influence of the phacoemulsification with posterior continuous curvilinear capsulorhexis and anterior vitrectomy on after cataract:a Meta-analysis / 眼科

Objective To evaluate the functional outcomes of the phacoemulsification(Phaco)with posterior continuous curvilinear capsulorhexis(PCCC),or with PCCC and anterior vitrectomy(AV)on after cataract.Design Meta analysis based on the reference searching.Participants A comprehensive electric search in MEDLINE,CNKI,CBMdisc,VIP information,CMCC,CCPD,SSreader,21dmedia and a manual search in related textbooks,journals,congress articles and their references in English and Chinese.Methods Strictly include and exclude the relevant articles from the resource with statistical criterion and get the needing data.Statistically analysed the data with software of Review Manager4.2.2,SPSS10.0.Heterogeneity of the included articles was tested that used to select appropriate effect model to Meta-analysis.Treatment effect was measured as odds ratio between Phaco with PCCC group and Phaco with PCCC+AV group.Change the selected effect model and calculate the fail-safe number(Nfs)to assess the sensitivity and specificity of the research.Main Outcome Measures Sensitivity,heterogeneity,the according confidence intervals(CI)and Nfs.Results Six studies were included,with a sum of 305 eyes.With the outcomes of heterogeneity test,the fixed effect model was used in both groups to calculate OR.The pooled OR of after cataract was 0.13(95%CI is 0.06-0.25).Sensitivity analysis demonstrated that no disproportionate influences of individual study.And Nfs=76.8,the result was confirmed.Conclusion Phacoemulsification with posterior continuous curvilinear capsulorhexis and anterior vitrectomy is superior to phacoemulsification with posterior continuous curvilinear capsulorhexis on preventing after cataract.