Silicone Intraocular Lens Research Articles

Adherence test of Staphylococcus epidermidis on the surface of different material intraocular lenses

Background Postoperative endophthalmitis following intraocular lens(IOL)implantation is still one of the most feared complications of cataract surgery.Bacterial adhesion to IOLs during their insertion is a prominent etiological factor.The adhesion characteristics of bacteria to IOL are very vital for the prevention of endophthalmitis after cataract surgery.Objective The present study was to observe the in vitro adherence ability of Staphylococcus epidermidis to different intraocular lenses(IOLs)and compare the results in bacterial counting between scanning electron microscopy(SEM)photographs and quantitative cultures. Methods Five types of IOLs,including hydrophobic acrylic IOL,polymethylmethaerylate(PMMA)IOL,heparin-surface-modified(HSM) PMMA IOL,silicone(SI)IOL and hydrophilic acrylic IOL,were put into S.epidermidis(ATCC 12228)suspension for 1 hour.The bacterial adhesion numbers on the IOL surfaces were counted by quantitative cultures and scanning electron microscopy(SEM) photographs. Results Quantitative culture counting of viable adherent bacteria released by sonication showed that hydrophobic acrylic IOL and PMMA IOL were more likely for bacteria to attach.The number of bacteria on the five types of IOL surfaces showed significant differences(F=100.084,P=0.000).No significant differences were found in the number of bacteria between hydrophilic acrylic IOL and HSM-PMMA IOL (t=2.285,P=0.052)with the quantitative culture method.Direct counting of adherent bacteria in SEM photographs revealed that there were significant differences in bacterial adhesion numbers among difierent IOL material groups,with the numbers from high to low as follows:Hydrophobic IOL＞PMMA IOL＞SI IOL＞Hydrophilic IOL＞HSM-PMMA IOL(F=118.065,P=0.000).The counting method by SEM method was superior to that by quantitative cultures (t=5.019,P=0.000). Conclusion The bacterial adhesion ability varies upon the difference of IOL materials.Less bacterial adhesion is found on hydrophilic acrylic IOL and HSM-PMMA IOL,implying that the use of IOLs made from these two materials during surgery could diminish the incidence of postoperative endophthalmitis and intraocular inflammation associated with IOLs implantation. Key words: Intraocular lens; Bacterial adhesion; Staphylococcus epidermidis; Endophthalmitis

Combined Correction of Axial Hyperopia and Astigmatism Using the Light Adjustable Intraocular Lens

To determine whether residual spherical and cylindrical errors could be corrected postoperatively using spatially profiled UV light irradiation in patients with axial hyperopia undergoing cataract surgery and implantation of a light adjustable, silicone intraocular lens (LAL). We conducted a prospective, nonrandomized clinical trial. The LALs were implanted in eyes with axial lengths <22.20 mm and were treated with a spatial intensity profile delivered by a digital light delivery device to induce a targeted spherical and cylindrical refractive change postoperatively. Once the desired correction was achieved, the LAL was treated again to lock-in the lens power. We studied 15 eyes of 15 patients with axial hyperopia. The manifest refraction, uncorrected visual acuity (UCVA), and best spectacle-corrected visual acuity (BCVA) were determined with follow-up time of 12 months to determine the achieved refractive corrections and their stability. We measured UCVA, BCVA, achieved versus targeted refractive outcome, and refractive stability with a follow-up time of 12 months. Of 15 eyes, 14 (93%) achieved ± 0.5 diopters (D), and 10 (67%) were within ± 0.25 D of the targeted refractive adjustment up to 12 months postoperative follow-up. Only 1 treated eye showed a change of 0.38 D in manifest spherical equivalent refraction, the remaining 14 eyes showed <0.25 D change between 1 month post lock-in, and at the 3-, 6-, and 12-month postoperative visits. The light-adjustable lens is a promising technology with the potential to reduce the rate of postoperative refractive surprises up to 2 D of spherical and cylindrical errors after cataract surgery. Postoperative refractive errors were successfully corrected with precision and significant improvement in UCVA and without compromising BCVA using the light-adjustable intraocular lens technology. The data demonstrate the stability of the achieved refractive change after the adjustment and lock-in procedures.

Pathology of 157 human cadaver eyes with round-edged or modern square-edged silicone intraocular lenses: Analyses of capsule bag opacification

To assess the degree of capsular bag opacification in human cadaver eyes with silicone intraocular lenses (IOLs), specifically comparing the differences between round-edged IOLs and modern square-edged IOLs. John A. Moran Eye Center, University of Utah, USA. Experimental study. The eyes were immersed in 10% formalin on enucleation. They had anterior segment scanning with a very-high-frequency ultrasound (Artemis). After the eyes were sectioned at the equator, gross examination of the anterior segment was performed from the posterior aspect to assess the degree of capsular bag opacification, coverage of the IOL edge by the anterior capsule, and IOL fixation. Selected eyes also had histopathologic examination. Eighty-seven eyes with a 3-piece round-edged IOL, 43 with a 3-piece square-edged IOL, 26 with a 1-piece plate IOL, and 1 with an accommodating IOL design were included in the analyses of capsular bag opacification. Comparison between 3-piece round-edged IOLs and square-edged IOLs showed statistically significant differences in central posterior capsule opacification (PCO) (P=.0001687) and peripheral PCO (P<.0001). In eyes with square-edged IOLs, PCO had a tendency to start in areas without capsulorhexis coverage of the optic. Twenty-one of 26 eyes with a silicone plate IOL had a neodymium:YAG posterior capsulotomy for dense PCO. This first study using pseudophakic human cadaver eyes that includes a significant number of modern 3-piece silicone IOLs with square optic edges confirmed the role of this design in the prevention of PCO. No author has a financial or proprietary interest in any material or method mentioned.

Biocompatibility of hydrophilic acrylic, hydrophobic acrylic, and silicone intraocular lenses in eyes with uveitis having cataract surgery: Long-term follow-up

To evaluate the long-term uveal and capsular biocompatibility of 5 intraocular lenses (IOLs) in eyes with uveitic cataract. Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. Comparative case series. Patients with uveitis of various origin were consecutively recruited for cataract surgery (1998-2006) and received 1 of 3 hydrophilic acrylic IOLs (Hydroview, AcrySof MA60BM, or Injectacryl F3000), a silicone IOL (CeeOn 911), or a hydrophilic acrylic IOL with heparin surface modification (BioVue(3)). A 7-year follow-up was performed in the Hydroview, AcrySof, and CeeOn groups. Visual acuity, anterior chamber flare measurements, specular microscopy, biomicroscopy, and fundoscopy were performed postoperatively at 6 months and 1, 2, and 3 years. The study enrolled 136 eyes of 115 patients. There were no significant differences in anterior chamber flare results between the 5 groups. The Hydroview group had the highest grade and the CeeOn IOL and AcrySof groups had the lowest grade of posterior capsule opacification. The BioVue(3) and Injectacryl IOLs had good uveal biocompatibility. Patients in all groups had better visual acuity postoperatively. Overall, patients with uveitis benefited from cataract surgery. The long-term results indicate that all sharp-edged hydrophilic and hydrophobic IOLs performed well in eyes with uveitis. Higher uveal biocompatibility was achieved with the modern hydrophilic acrylic IOLs than with the hydrophobic acrylic IOL. Modern hydrophilic acrylic IOLs seem to be a good option in these cases. No author has a financial or proprietary interest in any material or method mentioned.

Outcome of cataract surgery with primary intraocular lens implantation in children

AimTo report the results of paediatric cataract surgery with primary intraocular lens (IOL) implantation.MethodsChildren with congenital or developmental cataract who underwent phacoaspiration with posterior chamber (PC) IOL implantation were retrospectively...

Comparison of the outcome of implantation of hydrophobic acrylic versus silicone intraocular lenses in pediatric cataract: prospective randomized study

Objective: To compare the postoperative performance of hydrophobic acrylic and silicone square-edge intraocular lenses in pediatric cataract. Design: Prospective randomized study. Participants: Forty-one eyes of 41 children (age 1 month to 8 years) with congenital or developmental cataract. Methods: Children were randomly divided into 2 groups. All participants underwent phacoaspiration, primary posterior capsulotomy, and anterior vitrectomy. Group A ( n = 21) eyes were implanted with acrylic hydrophobic AcrySof SA60AT intraocular lenses (IOLs), and those of Group B ( n = 20) were implanted with silicone Tecnis Z9000 IOLs. The children were evaluated for anterior chamber reaction, IOL position, posterior capsular opacifica-tion (PCO), intraocular pressure, best-corrected visual acuity (BCVA), corneal status, and refractive errors. Results: Postoperatively, 2 eyes in each group had significant anterior chamber reaction with fibrin membrane formation. IOLs were in the capsular bag in all but 1 eye in both groups. Seven eyes in the acrylic group and 6 eyes in the silicone group achieved visual acuity of 20/40 or better. None of the eyes showed glaucoma. BCVA at 1 year was similar in both groups. In the acrylic hydrophobic group, 14 eyes needed hypermetropic correction and 7 eyes were myopic, and in the silicone group 10 eyes had myopia and 10 eyes had hypermetropia at 1 year postoperatively. PCO at 1 yearfollow-up was more common in eyes implanted with acrylic hydrophobic IOLs (5 eyes) than silicone IOLs (2 eyes). Conclusions: Both square-edge hydrophobic acrylic and silicone IOLs were found to be compatible and safe for use in pediatric cataract surgery with similar visual axis clarity and postoperative outcome.

Retinal safety of the irradiation delivered to light-adjustable intraocular lenses evaluated in a rabbit model

To evaluate the safety to the retina of a light-delivery device used to irradiate a light-adjustable intraocular lens (IOL) after implantation in a rabbit model. John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. In this study, rabbits had phacoemulsification with implantation of an ultraviolet (UV)-filtering light-adjustable IOL (study IOL) in 1 eye and a custom-made silicone IOL without a UV filter (control IOL) in the opposite eye. The study IOLs were irradiated at 1.0, 2.0, 3.0, and 5.0 times the expected maximum UV irradiation doses and the control IOLs, at 0.3, 0.6, 1.0, and 2.0 times. One week after irradiation, slitlamp and fundus (indirect ophthalmoscopy) examinations were performed. The rabbits were then humanely killed and their eyes enucleated and processed for histopathology. The 16 eyes with the study IOL (with UV filter) showed no signs of corneal, anterior segment, or retinal toxicity on histopathologic evaluation. The 16 eyes with the control IOL (no UV filter) also showed no signs of corneal or anterior segment toxicity; however, 3 eyes receiving the higher radiation doses had focal areas of retinal damage consistent with laser burn. Pigmented rabbit eyes with a light-adjustable IOL with a UV filter showed no signs of retina toxicity after near-UV light exposure up to 5 times the expected maximum treatment dosage. No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

Adjustierung von sphärozylindrischen Refraktionsfehlern bei hyperopen Augen: 6 Monatsergebnisse nach Kataraktchirurgie und Implantation einer lichtadjustierbaren Intraokularlinse

The aim of this study was to determine whether residual spherical and cylindrical errors could be corrected postoperatively in a non-invasive manner using ultraviolet irradiation in patients with axial hyperopia undergoing cataract surgery and implantation of a light-adjustable lens, silicone intraocular lens (LAL) (Calhoun Vision, Pasadena, CA). In a prospective, non-randomised clinical trial at Center for Vision Science, Ruhr University Eye Clinic, Bochum, Germany, 15 eyes of 15 patients with axial hyperopia (less than 22.2 mm) were studied. The manifest refraction, uncorrected visual acuity (UCVA), and best spectacle-corrected visual acuity (BSCVA) were determined with a follow-up time of six months to determine the achieved refractive corrections and their stability. The adjustment and lock-in procedures were well tolerated by patients. Preoperative refraction was in mean + 2.56 D as spherical equivalent, postoperative before adjustment + 1.01 D, one month after lock-in procedure + 0.03 D, after 3 months + 0.12 D and after 6 months 0.0 D (± 0.21 D). 6 months after lock-in all patients reached an uncorrected visual acuity of 20/30 or better, 10 of 15 patients reached 20/25 and 1 patient 20/20. The data demonstrate the stability of the achieved refractive change after the adjustment and lock-in procedures. Postoperative refractive errors were successfully corrected with precision and significant improvement in UCVA and without compromising BSCVA using the light adjustable intraocular lens technology. Our data demonstrate the stability of the achieved refractive change after the adjustment and lock-in procedures. The light-adjustable lens is a promising technology with the potential to eliminate postoperative refractive surprises of up to 2 diopters of refractive and cylindrical error following cataract surgery.

Calcification of Different Designs of Silicone Intraocular Lenses in Eyes with Asteroid Hyalosis

To describe the association between calcification of older and newer designs of silicone intraocular lenses (IOLs) and asteroid hyalosis. Case series with clinicopathologic correlation. Sixteen silicone IOLs explanted because of decreased visual acuity associated with opacifying deposits on the posterior optic surface. All 16 lenses underwent gross and light microscopic analyses. Selected lenses underwent alizarin red staining or scanning electron microscopy coupled with energy dispersive x-ray spectroscopy for elemental composition. Clinical data in each case were obtained by a questionnaire sent to the explanting surgeons. Clinical data in relation to 111 hydrophilic acrylic lenses explanted because of calcification also were assessed for comparison. Deposit morphologic features and location were evaluated under gross and light microscopy. The calcified nature of the deposits was assessed by histochemical staining and surface analyses. Clinical data obtained included age at IOL implantation, gender, implantation and explantation dates, as well as history of neodymium:yttrium-aluminum-garnet laser treatment. The presence of asteroid hyalosis in the affected eye was investigated for the explanted silicone and hydrophilic acrylic lenses. The 16 lenses were of 8 designs manufactured from different silicone materials, which were explanted 9.21+/-3.66 years after implantation. Neodymium:yttrium-aluminum-garnet laser applications performed in 12 cases partially removed deposits from the lens, followed by a gradual increase in their density after the procedures. The presence of asteroid hyalosis was confirmed in 13 cases; no notes regarding this condition were found in patient charts in the other 3 cases. The deposits were only on the posterior optic surface of the silicone lenses and were composed of calcium and phosphate. A history of asteroid hyalosis was not found in relation to any of the 111 cases of postoperative calcification of hydrophilic acrylic lenses. Including this current series, there are 22 cases of calcification of silicone lenses involving 8 designs manufactured from different silicone materials described in the literature. The presence of asteroid hyalosis was confirmed in 86.4% of cases. These findings may be added to the list of pros and cons surgeons consider when selecting or recommending an IOL.

Postoperative opacification of polymethylmethacrylateintraocular lens

Abstract Background: Opacification of ophthalmic devices has been previously reported in silicone scleral buckle, Molteno implant, and intraocular lens opacification. However, there is no report on polymethyl methacrylate (PMMA) intraocular lens (IOL) calcification. Objective: Report the clinical feature, histopathologic and spectrophotometer analysis of opacified three-piece PMMA IOL. Method: A 60-year-old diabetic patient reported decreased visual acuity in her right eye, which had undergone phacoemulsification with PMMA IOL implantation. The ophthalmic examination revealed a white homogeneous opacification of posterior surface of the IOL. The explanted IOL was analyzed using scanning electron microscopy, energy dispersive spectroscopy, and alizarin red staining. Results: The scanning electron microscope analysis showed granular deposits on posterior surface of the IOL. Using energy dispersive spectroscopy analysis, calcium and phosphate peaks were revealed, which was confirmed by positive for alizarin red staining. Conclusion: This case report provided evidence of PMMA IOL calcification caused by calcium and phosphate deposits. The possible etiologies were extrinsic and/or intrinsic factors.

Evaluation of the Calhoun Vision UV Light Adjustable Lens Implanted Following Cataract Removal

To evaluate the effectiveness of a silicone intraocular lens (IOL) that can be adjusted following implantation using ultraviolet (UV) irradiation. Prospective clinical trial of 40 patients (40 eyes) with visually significant cataract. Participants underwent small-incision phacoemulsification followed by implantation of a light-adjustable, silicone IOL (Light Adjustable Lens [LAL], Calhoun Vision). All patients were required to wear UV-protective eyewear at all times, until final lock-in. Pre- and postoperative clinical parameters included distance visual acuity and manifest refraction. At average 2 weeks postoperative (range: 10 to 21 days), patients were seen and refracted to determine type and magnitude of refractive error needing correction. All patients required an initial adjustment of the LAL, whereas 28 required a second UV treatment and none required a third adjustment. At 4 months postoperative, mean refraction was 0.04±0.37 diopters (D) (range: -0.88 to 0.50 D), mean sphere was 0.24±0.40 D (range: -0.50 to 0.75 D), and mean cylinder was 0.41±0.25 D (range: 1.00 to 0.0 D). Eighty-one percent of eyes gained 2 or more lines of corrected distance visual acuity. The adjustment and lock-in procedures were well tolerated by patients. The Calhoun Vision LAL is a promising technology with the potential to eliminate postoperative refractive surprises of up to 2.00 D of refractive and cylindrical error following implantation.

Intraocular lens as a drug delivery system for dexamethasone

To evaluate the effect of an intraocular lens (IOL) coated with dexamethasone on postoperative inflammation after cataract surgery. Clear lens extraction was performed bilaterally in eight 8-week-old rabbits. An uncoated silicone IOL (CeeOn; AMO, Santa Ana, CA, USA) was implanted in one randomly selected eye. In the other eye, the same silicone IOL model was implanted but was coated with dexamethasone. Aqueous humour was obtained preoperatively and on days 1, 3, 7, 14 and 28 postoperatively. Three inflammatory parameters were measured and compared between the eyes: prostaglandin E2 (PGE2), white blood cell (WBC) count and protein content. The animals were killed on day 28 postoperatively. PGE2 levels measured on days 1, 3 and 7 were significantly lower in eyes with a coated IOL compared to eyes with an uncoated IOL (p < 0.01). The WBC count was significantly lower in eyes with a coated IOL on days 1 (p < 0.01) and 3 (p < 0.05). There was significantly less protein in eyes with a coated IOL on days 1 and 3 (p < 0.01). Coating a silicone IOL with dexamethasone significantly reduced postoperative inflammation after clear lens extraction in rabbits.

Surgical Management of a Posterior Dislocated Intraocular Lens After Descemet Stripping Automated Endothelial Keratoplasty

To describe the occurrence and management of a posterior chamber intraocular lens (IOL) dislocation into the vitreous cavity after Descemet stripping automated endothelial keratoplasty (DSAEK). We describe the clinical course of a pseudophakic patient with Fuchs endothelial dystrophy and previous Neodymium: Yttrium-Aluminum-Garnet (Nd:YAG) laser capsulotomy who underwent DSAEK. On postoperative day 10, the patient was examined and a detachment of the DSAEK graft was noted. After disc reattachment with use of an air bubble, the patient's vision did not clear because of persistent edema, but he appreciated a new large floater. A diagnosis of iatrogenic graft failure was made, and ultrasound examination confirmed dislocation of a plate-haptic silicone IOL into the vitreous cavity. The patient was treated with pars plana vitrectomy and concurrent penetrating keratoplasty. One year after penetrating keratoplasty, the patient had a visual acuity of 20/60 with mild neurotrophic keratopathy and irregular astigmatism. The use of intraocular air at the time of graft repositioning can induce posterior dislocation of an IOL in the setting of a YAG capsulotomy opening.

Interventions for preventing posterior capsule opacification.

Posterior capsule opacification (PCO) remains the most common long-term complication after cataract surgery. It can be treated by Nd:YAG laser capsulotomy, however this may lead to other complications and laser treatment is not available in large parts of the developing world. Therefore, many studies try to find factors influencing the development of PCO. To summarise the effects of different interventions to inhibit PCO. These include modifications of surgical technique and intraocular lens (IOL) design, implantation of additional devices and pharmacological interventions. We searched CENTRAL, MEDLINE, EMBASE, LILACS in March 2009 and reference lists of identified trial reports. We included only prospective, randomised and controlled trials with a follow-up time of at least 12 months. Interventions included modifications in surgical technique explicitly to inhibit PCO, modifications in IOL design (material and geometry), implantation of additional devices and pharmacological therapy compared to each other, placebo or standard treatment. We extracted data and entered it into RevMan. We compared visual acuity data, PCO scores and YAG capsulotomy rates and performed a meta-analysis when possible. Sixty six studies were included in the review. The review was divided into three parts. 1. Influence of IOL optic material on the development of PCO. There was no significant difference in PCO development between the different IOL materials (PMMA, hydrogel, hydrophobic acrylic, silicone) although hydrogel IOLs tend to have higher PCO scores and silicone IOLs lower PCO scores than the other materials. 2. Influence of IOL optic design on the development of PCO. There was a significantly lower PCO score (-8.65 (-10.72 to -6.59), scale 0 to 100) and YAG rate (0.19 (0.11 to 0.35)) in sharp edged than in round edged IOLs, however not between 1-piece and 3-piece IOLs. 3. Influence of surgical technique and drugs on the development of PCO. There was no significant difference between different types of intraoperative/postoperative anti-inflammatory treatment except for treatment with an immunotoxin (MDX-A) which led to a significantly lower PCO rate. Due to the highly significant difference between round and sharp edged IOL optics, IOLs with sharp (posterior) optic edges should be preferred. There is no clear difference between optic materials. The choice of postoperative anti-inflammatory treatment does not seem to influence PCO development.

Uveal and capsular biocompatibility of an intraocular lens with a hydrophilic anterior surface and a hydrophobic posterior surface

To evaluate the uveal and capsular biocompatibility of intraocular lenses (IOLs) with a hydrophilic anterior surface and a hydrophobic posterior surface in a rabbit model. Eye Center, Affiliated Second Hospital, College of Medicine, Zhejiang University, Hangzhou, China. Modified silicone IOLs were produced by grafting 2-methacryloyloxyethyl phosphorylcholine (MPC) onto the anterior IOL surface using a plasma technique. A contact-angle test characterized the hydrophilicity of the IOL surface; physical and optical properties were determined by State Food and Drug Administration (SFDA) standards. Rabbits had phacomulsification and implantation a modified silicone IOL, a control silicone IOL, or a hydrogel IOL. Postoperative inflammation was assessed by aqueous flare measurement, and PCO was evaluated by software analysis. Three months after surgery, attached cells on extracted IOLs were evaluated by light microscopy; PCO was evaluated by Miyake-Apple technique. Histologic sections of globes were used to assess lens epithelial cells (LECs) and extracellular matrix in the capsular bag. Contact angle data showed the MPC-modified IOL had a hydrophilic anterior surface and hydrophobic posterior surface. The properties of the modified IOLs met SFDA standards. There was no statistical difference in aqueous flare between the IOL groups at any time. The modified and control IOLs had less PCO than the hydrogel IOLs (P<.05). There were fewer cells on modified IOLs than on silicone IOLs (P<.05). The LECs and cortical remnants on modified IOLs had a rapid, fibroblastic appearance at the optic periphery; the center was clear. Results suggest that the MPC-modified IOL has excellent uveal and capsule biocompatibility from hydrophilic anterior surface and hydrophobic posterior surface properties, respectively.

Clinical results of ultrasound biometry in silicone oil-filled eye.

To evaluate a method of ultrasound biometry in silicone oil-filled eye and its clinical results. This was a series case study. According to the principle of measuring a distance with ultrasound, we compared the measured distance between a space filed with balanced salt solution and silicone oil at same height, to calculate a conversion factor (0.674) between them. A formula for corrective axial length in silicone oil-filled eye was established. The formula = ab + 0.674 x bc (a, b and c standing for the apex of the cornea, the posterior pole of the lens or the center of the capsular membrane and the anterior surface of the macular, respectively). The axial lengths of 150 silicone oil-filled eyes in 150 cases were then measured before and after silicone oil removal with Vivid 7 Dimension ultrasound. According to the axial length, they were divided into two groups, namely group 1 (the length < 25 mm) and group 2 (the length > or = 25 mm). In 76/150 eyes, before combined silicone oil removal and intraocular lens (IOL) implantation, the SRKT formula was used for intraocular lens calculation; the post-operative actual refraction was compared with the pre-operative predicted refraction and statistics analysis was made. The retinal condition of 150 silicone oil-filled eyes in 150 cases after 3 months' follow-up was stable after surgery. The results of the biometry were as follows. In the first group, the mean corrective axial lengths of 111 silicone oil-filled eyes before silicone oil removal was (22.77 +/- 1.00) mm (ranging from 21.10 to 24.90 mm); the mean axial lengths after silicone oil removal was (22.76 +/- 0.99) mm (ranging from 21.00 to 24.70 mm). The difference between them was not statistically significant (t = 0.518, P > 0.05). The vitreous cavity depth before and after silicone oil removal was (26.57 +/- 2.14) mm and (17.90 +/- 1.38) mm, respectively. The ratio of the latter to the former was 0.673 78. In the second group, the mean corrective axial lengths of 39 silicone oil-filled eyes before silicone oil removal was (26.52 +/- 1.31) mm (ranging from 25.00 to 30.58 mm); the mean axial lengths after silicone oil removal was (26.53 +/- 1.29) mm (ranging from 25.00 to 30.59 mm). The difference between them was not statistically significant (t = 0.109, P > 0.05). The vitreous cavity depth before and after silicone oil removal was (32.01 +/- 2.90) mm and (21.57 +/- 2.04) mm, respectively. The ratio of the latter to the former was 0.673 95. In 76 eyes with IOL, the post-operative actual refraction after at least 3 months follow-up was compared with the pre-operative predicted refraction (-1.50 DS) in both groups. The differences between them were not statistically significant (t(1) = 0.253, P(1) > 0.05; t(2) = 0.209, P(2) > 0.05) in each group. Ultrasound biometry in silicone oil-filled eye is accurate and simple, and has good results in clinical measurement.

Determination of albumin sorption to intraocular lenses by radiolabeling and confocal laser scanning microscopy

To determine albumin adsorption profiles and penetration depth of 3 intraocular lens (IOL) materials over time using confocal laser scanning microscopy (CLSM) and radiolabeling. Centre for Contact Lens Research, School of Optometry, and Department of Biology, University of Waterloo, Waterloo, Ontario, Canada. Poly(methyl methacrylate) (PMMA), silicone, and foldable hydrophilic acrylic IOLs were incubated in 0.5 mg/mL bovine serum albumin (BSA) for 1, 7, and 14 days. The BSA was conjugated with lucifer yellow VS to allow identification of the protein location by fluorescent imaging with CLSM. Next, the protein uptake was quantified using 2% (125)I-labeled BSA. Confocal laser scanning microscopy showed increasing BSA uptake for silicone and PMMA IOLs after 14 days of incubation (P<.05), with an apparent penetration depth of 8.7 microm +/- 1.9 (SD) and 9.2 +/- 1.4 microm, respectively. For hydrophilic acrylic IOLs, BSA was detected at a depth of 38 +/- 7.4 microm after 1 day, followed by an increase to 192.7 +/- 16.2 microm after 14 days. Despite the penetration depth into the hydrophilic acrylic IOLs, quantitative results confirmed that PMMA and hydrophilic acrylic deposited significantly less BSA (mean 278.3 +/- 41.7 ng and 296.5 +/- 33.1 ng, respectively) than silicone IOLs (mean 392.6 +/- 37.6 ng) (P<.05). Silicone and PMMA IOL materials showed BSA sorption near the lens surface only, while BSA penetrated deep into the hydrophilic acrylic IOL matrix. Combining the qualitative CLSM method and quantitative radiolabeling technique provided detailed information on protein interactions with implantable biomaterials.

Comparison of posterior capsule opacification development with 3 intraocular lens types: Five-year prospective study

To compare the effects of hydrophobic acrylic, silicone, and heparin-surface-modified poly(methyl methacrylate) (HSM PMMA) intraocular lenses (IOLs) on posterior capsule opacification (PCO). In this 5-year prospective study, the same surgeon performed standard phacoemulsification in patients who were randomized to implantation of a round-edged HSM PMMA IOL (809C), a round-edged silicone IOL (SI-40NB), or a sharp-edged hydrophobic acrylic IOL (AcrySof MA60BM). The neodymium:YAG capsulotomy rate was recorded. To evaluate PCO and the position of the anterior capsulorhexis, retroillumination digital photographs were taken 5 years postoperatively and analyzed using the POCOman computer-analysis system. After 5 years, there was no significant difference in the fraction or severity of PCO between the silicone IOLs and acrylic IOLs (both P =1.0). The silicone IOL group had a significantly higher capsulotomy rate (29%) than the acrylic IOL group (8%) (P=.0068). The HSM PMMA IOL group had a significantly higher PCO fraction, severity, and capsulotomy rate (54%) than the silicone and acrylic groups. In all eyes, the fraction (P=.0076) and severity (P=.0081) of PCO were statistically significantly higher when the anterior capsulorhexis was partly decentered than when it was completely on the optic; within each IOL group, there was no significant difference. After 5 years, there was no significant difference in the semiquantitative evaluation of PCO between the sharp-edged acrylic IOL and round-edged silicone IOL. Eyes with the HSM PMMA IOL had more PCO than eyes with the other IOLs.

F4H5: a novel substance for the removal of silicone oil from intraocular lenses

AimAdherent silicone oil on intraocular lenses (IOLs) following retinal detachment surgery induces large and irregular refractive errors and multiple images, and gives rise to glare, distorted and often poor vision....

Impact of fibronectin on surface properties of intraocular lenses

Physical properties of intraocular lens (IOL) surfaces determine biocompatibility. IOL hydrophobicity of commercially available IOLs with and without fibronectin (FN) coating can be determined by surface contact angle (SCA) measurements. SCA data of IOLs may allow for a rational selection of an IOL type as a function of underlying eye disease. University Hospital of Saarland, Homburg (Saar), Germany Thirteen IOL types were tested. IOLs were made of poly(methyl methacrylate)(PMMA), acrylate, or silicone. Select IOLs were surface modified by the manufacturer with heparin or a polysaccharide coating. SCA values of IOLs, either uncoated or precoated with FN, were determined using the sessile water drop method. SCA values ranged from 61.3 to 116.1 degrees for unmodified IOLs, with PMMA IOLs being more hydrophilic (median SCA, 74.1 degrees ), silicone IOLs more hydrophobic (median SCA, 113.3 degrees ), and acrylate IOLs intermediate (median SCA, 86.6 degrees ). Upon FN coating, all genuine acrylate lenses became significantly more hydrophilic while this effect was either nonsignificant or opposite on some PMMA and silicon IOLs. Heparin or polysaccharide surface modification resulted in significantly reduced SCA values. On acrylate IOLs, SCA values did not correlate with the aqueous content of the material. This study associates IOL materials, surface modifications, and the role of FN preadsorption with SCA values reflecting surface hydrophobicity versus hydrophilicity. It provides a rationale for specific IOL selection as a function of the clinical setting, and a basis for IOL development using tailored surface physicochemistry to enhance biocompatibility and to reduce susceptibility to implant infection.