Eradication of Posterior Capsule Opacification: Documentation of a Marked Decrease in Nd:YAG Laser Posterior Capsulotomy Rates Noted in an Analysis of 5416 Pseudophakic Human Eyes Obtained Postmortem.

OBJECTIVE: (1) To report the neodymium:yttrium-aluminum-garnet (Nd:YAG) laser posterior capsulotomy rate (%) of eight rigid and foldable intraocular lens (IOL) designs in a series of 5416 pseudophakic human eyes obtained postmortem, accessioned in our center between January 1988 and January 2000. (2) To identify factors that are instrumental in reducing the incidence of posterior capsule opacification, (PCO, secondary cataract) and hence the need for Nd:YAG laser posterior capsulotomy. DESIGN: Comparative autopsy tissue analysis. PARTICIPANTS: A total of 5416 globes with posterior chamber intraocular lens (PC-IOLs) obtained postmortem received from Lions Eye Banks between 1988 and 2000. METHODS: Miyake-Apple posterior photographic technique. Special reference was given to the presence or absence of Nd:YAG laser posterior capsulotomy orifice on the posterior capsule of each eye. MAIN OUTCOME MEASURES: The Nd:YAG laser posterior capsulotomy rate (%) as of January 2000 was documented. In addition, the Nd:YAG laser posterior capsulotomy rate for each lens was plotted on a monthly basis for the same period, creating a computerized trend or "timeline" for each IOL style. RESULTS: Relatively high Nd:YAG laser posterior capsulotomy rates ranging from 20.3% to 33.4% were noted with four relatively older designs (high incidence of implantation between 1988 and the early 1990s). Four modern foldable lOLs manufactured from silicone and acrylic materials had significantly lower Nd:YAG laser posterior capsulotomy rates ranging from 0.9% (Alcon Acrysof) to 17.1%. The difference in Nd:YAG rates among the eight IOL designs was found to be significant (P < 0.0001, chi-square test). Comparing foldable versus rigid designs, the foldable IOLs were associated with a much lower Nd:YAG laser posterior capsulotomy rate (14.1% vs. 31.1%). CONCLUSIONS: By use of the six factors regarding surgical technique and IOL choice described in this article, we strongly believe that the overall incidence of PCO and hence the incidence of Nd:YAG laser posterior capsulotomy is now rapidly decreasing from rates as high as 50% in the 1980s to early 1990s. Surgical tools and IOLs are now available to bring these rates down to single digits. Careful application and use of these tools by surgeons can genuinely lead in the direction of virtual eradication of secondary cataract, the second most common cause of visual loss worldwide.

Pediatric cataract surgery with hydrophilic acrylic intraocular lens.

PURPOSE: To assess the outcomes after hydrophilic acrylic intraocular lens (IOL) implantation during pediatric cataract surgery. METHODS: This was a retrospective chart review of children who underwent cataract surgery or secondary IOL implantation at Beirut Eye Specialist Centre, Rizk Hospital, between March 2002 and August 2007. RESULTS: A total of 57 eyes of 40 patients (20 boys) were included in this study. The average age at surgery was 48 ± 40 months (range, 5-172 months). Of these, 54 eyes had congenital or developmental cataracts and 3 eyes had traumatic cataracts. Primary cataract removal and IOL implantation accounted for 45 surgeries, and secondary IOL implantation accounted for 12 surgeries. Hydrophilic acrylic IOLs were implanted in all surgeries. Average follow-up time was 47 ± 21 months (range, 9-97 months). No intraoperative complications were recorded. Of the 57 eyes, 12 (21%) had postoperative complications, but only 7 (12%) required secondary intervention. Average best-corrected visual acuity improved from 2.0 ± 1.0 logMAR preoperatively to 0.8 ± 1.0 logMAR at last follow-up. Improved visual acuity was observed in 47 eyes (82.5%); 31 eyes (54.4%) had a visual acuity of ≥ 20/40 at the last follow-up. CONCLUSIONS: Hydrophilic acrylic IOLs appear to be suitable for use in pediatric cataract surgery. Results from this study suggest that, compared with hydrophobic IOLs, these IOLs produce similar complication rates, secondary intervention rates, and visual acuity results.

Modern cataract surgery: unfinished business and unanswered questions.

We summarize information, based on clinicopathologic studies over the past decade, on various cataract intraocular lens (IOL) procedures and modern "specialized" IOLs, that will help surgeons continuously improve long-term results for cataract patients. Although most operations do initially provide excellent refractive correction and visual rehabilitation, late complications occur. These sometimes are missed because they are outside of the routine period of follow-up care. We have tried to determine if the various techniques and IOLs truly deliver the long-term results that we desire. Most safety and efficacy information is derived from the manufacturer and is passed through the U.S. Food and Drug Administration (FDA). This is often based on limited, relatively short-term observations made by the manufacturer. After a lens receives FDA approval, there are few means to assess the outcome of each procedure and lens years later. We rarely hear of a 10- or 20-year follow-up study. We have found that one of the best means to assess long-term results is pathologic analyses. We discuss recently studied aspects of pathologic reactions, such as posterior capsule opacification, intracapsular fibrosis, glistenings, intralenticular opacification, and other issues with the various IOL platforms; we then present a clinicopathological overview of tissues and IOLs from our database. These include hydrophobic and hydrophilic acrylic designs, plate lenses, and a dual optic lens.

Safety assessment of a new single-use small-incision injector for intraocular lens implantation.

PURPOSE: To evaluate the safety of a new injector, the Raysert R-INJ-04/18, for implantation of the C-flex intraocular lens (IOL). SETTING: Ophthalmology Department, Kaplan Medical Center, Rehovot, Israel. DESIGN: Experimental study. METHODS: Sixty IOLs were subdivided into 2 equally sized groups. Group A IOLs were injected using the established R-INJ-04 injector, and those in Group B were injected with the new injector. The IOLs were injected into a Petri dish. Subsequently, all IOLs and injectors were evaluated macroscopically and microscopically and then photographed under light microscopy (LM). Two IOLs in each group were randomly chosen and sent for evaluation by scanning electron microscopy (SEM) and energy dispersive analysis of x-ray. All remaining IOLs were sent for power and modulation transfer function (MTF) analysis. RESULTS: All Group B IOLs were successfully injected without evident signs of scratching, cracks, or deposits on LM and SEM examination. In Group A, findings were confined to a singular incidence of a small deposit detected on the periphery of the posterior optical surface of the IOL, with corresponding findings detected on the injector nozzle. No signs of scratching, cracks, or deposits were found in the rest of the IOLs or injectors. The power and MTF analyses were within the normal range for all IOLs. CONCLUSION: The new 1.8 mm external diameter soft-tipped injector for 2.4 to 2.2 mm incisions was shown to be safe for the implantation of the C-flex 21.0 diopter IOL.

Mechanical ventilation, health, and quality of life following spinal cord injury.

OBJECTIVE: To examine differences in perceived quality of life (QOL) at 1 year postinjury between people with tetraplegia who required mechanical ventilation assistance at discharge from rehabilitation and those who did not. DESIGN: Prospective cross-sectional examination of people with spinal cord injury (SCI) drawn from the SCI Model Systems National Database. SETTING: Community. PARTICIPANTS: People with tetraplegia (N=1635) who sustained traumatic SCI between January 1, 1994, and September 30, 2008, who completed a 1-year follow-up interview, including 79 people who required at least some use of a ventilator at discharge from rehabilitation. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Satisfaction With Life Scale (SWLS); Craig Handicap Assessment and Reporting Technique (CHART)-Short Form Physical Independence, Mobility, Social Integration, and Occupation subscales; Patient Health Questionnaire-9 (PHQ-9), Medical Outcomes Study 36-Item Short-Form Health Survey self-perceived health status. RESULTS: Significant differences were found between the ventilator-user (VU) group and non-ventilator-user (NVU) group for cause of trauma, proportion with complete injury, neurologic impairment level, and number of rehospitalizations. The NVU group had significantly higher SWLS and CHART Social Integration scores than the VU group after controlling for selected covariates. The NVU group also had more positive perceived health status compared with a year previously and a lower incidence of depression assessed by using the PHQ-9 than the VU group. There were no significant differences between groups for perceived current health status. CONCLUSIONS: People in this study who did not require mechanical ventilation at discharge from rehabilitation post-SCI reported generally better health and improved QOL compared with those who required ventilator assistance at 1 year postinjury. Nonetheless, the literature suggests that perceptions of QOL improve as people live in the community for longer periods.

Correlación clínico-patológica de las Microvacuolas o ‘Glistenings’ en 100 lentes intraoculares (Lios) Acrysof Explantados / Clinicopathological correlation of microvacules or ‘glistenings’ in 100 explanted AcrySof intraocular lens (IOLs)

Resumen Propósito: analizar los LIOs acrílicos hidrofóbicos AcryS of de nuestro banco de lentes explantados para establecer la presencia de microvacuolas(glistenings), determinar su frecuencia y definir si existe una correlación con los datos clínicos para cada uno.Materiales y Métodos: se realizó análisis clínico-patológico de todos los lentes hidrofóbicos AcrySof® (n=100) que hacen parte del banco de más de 5.000 explantes de nuestro laboratorio. Se efectuó evaluación microscópica y se determinó la presencia de las microvacuolas; adicionalmente se estimó la severidad de las mismas y se hizo una correlación con los datos clínicos para cada lente.Resultados: el análisis foto microscópico reveló la presencia de microvacuolas en 43 de los 100 LIOs evaluados: las microvacuolas fueron clasificadas como...

Purpose:To analyze the AcrySof hydrophobic intraocular lens from our database in order to establish the presence of the microvacuoles (glistenigs), determine its frequency, and define clinicopathological correlation in each case.Materials and Methods: A clinicopathological analysis was performed in all the explanted AcrySof IOLs (n=100) that were accessioned in ourlaboratory database of more than 5,000 explants. Applying photo microscopy, we estimated the number of ‘glistenings’cases, evaluated their severity, and correlated them with clinical findings.Results: The laboratory analysis revealed microvacules in 43 out of the 100 evaluated lenses. Of those cases, 14 were mild, 17 were moderate, and 12 were marked. Of the 43 lenses in which the vacuoles were identified, only 6 had been diagnosed clinically...

Light scatter on the surface of AcrySof intraocular lenses: part II. Analysis of lenses following hydrolytic stability testing.

BACKGROUND AND OBJECTIVE: To investigate the surface light scatter and optical quality of AcrySof lenses (Alcon Laboratories, Inc., Fort Worth, TX) following simulated aging of 20 years. MATERIALS AND METHODS: AcrySof lenses were exposed to exaggerated thermal conditions to simulate up to 20 years of aging and were tested for surface light scatter and optical quality (modulation transfer function). RESULTS: There were no significant differences from baseline for either the surface light scatter or optical quality of the lenses over time. CONCLUSION: The current study demonstrated that surface light scatter on AcrySof lenses did not increase under conditions simulating 20 years of aging. Because the simulated aging environment contained no protein, this work indirectly supports the finding that surface light scatter is due to the deposition of a biomaterial on the lens surface rather than changes in the material. Optical performance integrity of the test lenses was maintained under severe environmental conditions.

Light scatter on the surface of AcrySof intraocular lenses: part I. Analysis of lenses retrieved from pseudophakic postmortem human eyes.

BACKGROUND AND OBJECTIVE: To investigate the cause of light scatter measured on the surface of AcrySof intraocular lenses (Alcon Laboratories, Inc., Fort Worth, TX) retrieved from pseudophakic postmortem human eyes. MATERIALS AND METHODS: Ten intraocular lenses (Alcon AcrySofModel MA60BM) were retrieved postmortem and analyzed for light scatter before and after removal of surface-bound biofilms. RESULTS: Six of the 10 lenses exhibited light scatter that was clearly above baseline levels. In these 6 lenses, both peak and average pixel density were reduced by approximately 80% after surface cleaning. CONCLUSION: The current study demonstrates that a coating deposited in vivo on the lens surface is responsible for the light scatter observed when incident light is applied.

A new classification of calcification of intraocular lenses.

OBJECTIVE: To define and classify the major types of intraocular lens (IOL) calcification. DESIGN: Retrospective observational case series with clinicopathologic correlation. PARTICIPANTS: More than 400 IOLs explanted because of opacification. METHODS: The authors reviewed the clinical information and histologic findings of all IOLs that had been explanted because of opacification or calcification of the IOLs accessioned in their laboratory between January 1999 and December 2004. MAIN OUTCOME MEASURE: The proposed mechanism that led to calcification of each IOL design. RESULTS: Three major types of calcification were identified: (1) primary calcification, (2) secondary calcification, and (3) false-positive calcification or pseudocalcification. The primary form refers to calcification that is inherent in the IOL, that is, is based on possible inadequate formulation of the polymer, fabrication of the IOL, or issues with its packaging process. The calcification presumably occurs in otherwise normal eyes and generally is not associated with preexisting diseases. The secondary form refers to deposition of calcium onto the surface of the IOL most likely the result of environmental circumstances (e.g., changes in the aqueous milieu surrounding the implanted IOL associated with preexisting or concurrent diseases or indeed any condition that has disrupted the blood-aqueous barrier). By definition, it is not related to any problem with the IOL itself. The false-positive or pseudocalcification refers to those cases in which other pathology is mistaken for calcification or false-positive staining for calcium occurs. CONCLUSIONS: When evaluating the pathogenesis and nature of IOL calcification in or on any given design, one should categorize it according to these types. Primary calcification is IOL related and the IOL should be withdrawn or modified to correct the problem. After the cause is identified and the lens is implanted again, patients should be followed up for up to 2 years to be sure the problem is alleviated. Secondary calcification is by definition not IOL related; it may occur with virtually all IOL designs implanted under various adverse circumstances. No IOL, hydrophilic or hydrophobic, is immune to secondary calcification. The false-positive form is recognized readily in the laboratory and this erroneous diagnosis is avoided.

Validity of the walking scale for spinal cord injury and other domains of function in a multicenter clinical trial.

OBJECTIVE: To demonstrate criterion (concurrent and predictive) and construct validity of the Walking Index for Spinal Cord Injury (WISCI) scale and other walking measures in the Spinal Cord Injury Locomotor Trial (SCILT). DESIGN: Prospective multicenter clinical trial of a walking intervention for patients with acute traumatic spinal cord injury (SCI). PARTICIPANTS/ METHODS: Body weight-supported treadmill training was compared to overground mobility training in 146 patients with incomplete SCI (C4 to L3) enrolled within 8 weeks of onset and treated for 12 weeks. Primary outcome measures were the Functional Independence Measure (FIM), 50-foot walking speed (50FW-S), and 6-minute walking distance (6MW-D), tested 3, 6, and 12 months after entry. Secondary measures were the Lower Extremity Motor Score (LEMS), Berg Balance Scale (BBS), WISCI, and FIM locomotor score (LFIM), assessed at 6 centers by blinded observers. Data for the 2 arms were combined since no significant differences in outcomes had been found. RESULTS: Correlations with WISCI at 6 months were significant with BBS (r = .90), LEMS (r = .85), LFIM (r = .89), FIM (r = .77), 50FW-S (r = .85), and 6MW-D ( r = .79); similar correlations occurred at 3 and 12 months. Correlations of change scores from baseline WISCI were significant for change scores from baseline of LEMS/BBS/LFIM. Correlation of baseline LEMS and WISCI at 12 months were most significant (r = .73). The R(2) of baseline LEMS explained 57% of variability of WISCI levels at 3 months. CONCLUSION: Concurrent validity of the WISCI scale was supported by significant correlations with all measures at 3, 6, and 12 months. Correlation of change scores supports predictive validity. The LEMS at baseline was the best predictor of the WISCI score at 12 months and explained most of the variance, which supported both predictive and construct validity. The combination of the LEMS, BBS, WISCI, 50FW-S, and LFIM appears to encompass adequate descriptors for outcomes of walking trials for incomplete SCI.

Experimental studies on nonpenetrating filtration surgery using the CO2 laser.

BACKGROUND: This study evaluated the use of a CO2 laser for performing deep sclerectomy in nonpenetrating filtration surgery. METHODS: Three experimental models were performed: enucleated sheep and cow eyes (n=18) to determine optimal irradiation parameters, live rabbit eyes (n=20) to test feasibility, and cadaver eyes (40 procedures in 20 eyes) to study effects in human eyes tissue. After a half-thickness scleral flap was created, deep sclerectomy was performed by CO2 laser applications on the scleral bed down to the trabeculo-Descemet's membrane. RESULTS: Fluid percolation was repeatedly achieved without penetration in sheep and cow eyes using scanned laser energy of 5-10 W at a pulse duration of 200 micros and a working distance of 35 cm. In live rabbits, deep sclerectomy was achieved without perforation in 19/20 eyes. Intraocular pressure was significantly decreased on the first postoperative day (10.3+/-5.1 mmHg lower, on average, than in the nonoperated fellow eye; P<0.001), and this persisted for 21 days. Operations on all cadaver eyes resulted in effective fluid percolation. Penetration of the scleral wall occurred in five cases only after repeated laser applications with high energy. Histologically, a thin sclerocorneal intact wall was demonstrated at the sclerectomy bed. Collateral tissue damage did not extend beyond 100 microm, and adjacent structures remained unharmed. CONCLUSIONS: CO2 laser-assisted deep sclerectomy is a feasible and apparently safe procedure.

Three-hundred-sixty degree barrier effect of a square-edged and an enhanced-edge intraocular lens on centripetal lens epithelial cell migration Two-year results.

PURPOSE: To study the 360-degree barrier effect of an intraocular lens (IOL) with a square edge at the optic and an enhanced square edge at the optic-haptic junctions (Rayner 570C C-flex) on centripetal migration of lens epithelial cells (LECs) over a 2-year period. SETTING: Department of Ophthalmology, Scarborough Hospital, Scarborough, United Kingdom. METHODS: In a prospective study of 40 consecutive eyes, a C-flex IOL was implanted in the bag after phacoemulsification surgery. Eyes with intraoperative complications, requiring additional procedures, without 360-degree overlap of the optic, or with capsule block syndrome were excluded. Follow-up was at 6, 10, 18, and 24 months. At each visit, high-magnification retroillumination digital photographs were taken using a slitlamp-attached digital camera. The barrier effect to LEC migration across the optic edge and the enhanced square edge at the optic-haptic junction was graded as complete (no epithelial pearls or sheet), partial (few epithelial pearls without sheet), and minimal/none (epithelial sheet behind the IOL optic). RESULTS: Twenty-four patients came to the final follow-up at 24 months. Fifteen of these eyes (63%) had a complete barrier effect throughout the 360 degrees of the IOL. Three eyes (13%) had a partial barrier effect throughout the 360 degrees of the IOL. Three eyes had a complete optic barrier effect but a partial optic-haptic junction barrier effect. Three eyes had a partial optic barrier effect but a complete optic-haptic junction barrier effect. No eye had epithelial sheets extending behind the optic at any location. CONCLUSIONS: This study showed the barrier effect of the edge design of the C-flex IOL and the efficacy of the enhanced edge in preventing LEC migration at the optic-haptic junction. The enhanced edge was as effective as a sharp square edge in restricting the LEC migration.

Evaluation of a new soft tipped injector for the implantation of foldable intraocular lenses.

AIM: To evaluate the R-INJ-04 soft-tipped injector, a new injector with an integral round nozzle manufactured by Rayner Intraocular Lenses, England. METHODS: 16 Rayner C-flex intraocular lenses (IOLs; Rayner Intraocular lenses, England) ranging between +10 and +30 D (2 for each power) were tested. An ophthalmic viscoelastic device (Healon, AMO, Santa Ana, California, USA) was applied to the injectors. The IOLs were loaded according to the company injector's instructions for use and were injected into a Petri dish. After the injection, all the IOLs and nozzles were evaluated by gross (macroscopic) and microscopic analyses and photographed under a light microscope. One lens of each power and the cartridge used for the implantation were then sent for further analysis by scanning electron microscopy (SEM). The rest of the IOLs were tested for power and modulation transfer function (MTF). RESULTS: All the injections were successful. No damage to the IOLs or to the injectors was found by gross examination, light microscopy and SEM. No deposits were found on the IOL optical surfaces or haptics. Power and MTF analysis showed a close match with the original measurements. CONCLUSION: Our results suggest that the R-INJ-04 soft-tipped injector is safe for the implantation of the C-flex IOL with power range from 10 to 30 D. No structural damage to the IOLs or to the injectors was found, and the lens power and light transmission properties were not damaged in any way by the injection process.

Sir Nicholas Harold Lloyd Ridley: 10 July 1906 - 25 May 2001.

Sir Harold Ridley invented and refined the modern miracle of replacing lenses obscured by cataracts with plastic optical lenses, thus rendering a complete cataract cure. This operation, broadly termed the cataract-intraocular lens (IOL) operation, has since brought sight to many millions of people throughout the world, and continues to improve the quality of life of more than 10 million patients worldwide each year. Ridley not only launched this powerful and irreversible forward movement in the field of ophthalmology and the visual sciences, but through it he also helped give birth to the exciting and new field of artificial biodevice implantation as well as transplantation techniques now applied to many other organs and tissues of the body. He has therefore been credited with healing to create the relatively new specialty of biomedical engineering. Few of the millions of patients worldwide who now enjoy the benefits of the modern cataract - IOL operation are aware of the origin of this innovation. Indeed, few eye care professionals - even ophthalmic surgeons who implant them almost daily - are aware of the origin of the IOL - an invention that, as Harold himself liked to say, 'cured aphakia'. (The word aphakia comes from teh Greek, meaning absence of lens, the situation that occurs when a cataractous lens is surgically removed.)

Current concepts of ocular manifestations in Marfan syndrome.

Marfan syndrome is a widespread disorder of connective tissue. It is characterized by systemic and ocular features due to mutations in the fibrillin gene. Awareness and prompt recognition of the ocular complications of Marfan syndrome may enable improvement and preservation of sight. Studies have been performed in the last few years that enable a better understanding of the genetics of the syndrome, earlier diagnosis, and improvement in the surgical techniques and options.

Postoperative surface deposits on intraocular lenses in children.

PURPOSE: To report the clinicopathologic features of 4 intraocular lenses (IOLs) composed of 3 different hydrophilic biomaterials explanted from children who had postoperative opacification of the IOL optic. SETTING: David J Apple, MD, Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, USA. METHODS: The IOLs were explanted 20, 11, 22, and 25 months postoperatively from children aged 10, 3, 36, and 20 months old, respectively, at IOL implantation. Clinical data were obtained to correlate the findings with possible associated risk factors. The explanted IOLs were examined by gross and light microscopy. They were further analyzed with a stain for calcium, alizarin red 1%. Scanning electron microscopy and energy dispersive X-ray spectroscopy (EDS) were also performed. RESULTS: The primary reason for cataract surgery in Case 1 and Case 2 was persistent hyperplastic primary vitreous (PHPV); 1 patient received a B-Lens IOL (Hanita) and the other a Centerflex IOL (Rayner). The primary reason in Case 3 was familial bilateral congenital cataract and in Case 4, rubella cataract; both patients received a Hydroview IOL (Bausch & Lomb). All 4 IOLs had surface deposits on the optic, but the morphology of the deposits on the B-Lens and Centerflex IOLs was different than that in previously reported cases. The deposits in all four cases stained positive with alizarin red and consisted of calcium and phosphorus when imaged with EDS. CONCLUSIONS: Calcified deposits on 2 Hydroview IOLs explanted from children were similar to those seen in adults with the same IOL. The deposits on the B-Lens and Centerflex IOLs were probably secondary to a breakdown of the blood-aqueous barrier caused by preexisting PHPV.

Evaluation of lens epithelial cell migration in vivo at the haptic-optic junction of a one-piece hydrophobic acrylic intraocular lens.

PURPOSE: To evaluate the pattern of lens epithelial cell (LEC) ingrowth behind the intraocular lens (IOL) optic in patients implanted with the AcrySof SA60AT one-piece IOL. DESIGN: Retrospective case series. METHODS: Patients implanted with the AcrySof SA60AT one-piece IOL with complete overlap of the capsulorrhexis and IOL optic and no ocular pathology were selected from the practices of six surgeons. High-resolution digital images of the distribution of LECs were captured. Circumferential location and extent of LEC growth behind the optic were measured. RESULTS: Mean +/- SD follow-up was 13.2 +/- 1.7 months for 40 patients (mean age 72 years). LEC migration beyond the edge of the IOL optic was displayed by 57.5% (23/40) of patients. LECs migrated into the visual axis in 22.5% (9/40) of patients, leading to a visual acuity of <6/9 (20/30) in 10% (4/40) of patients. Cell migration was located preferentially at the optic-haptic junction. Serial photographs were used to monitor LEC migration over time. In some cases, LECs extended from the opposing optic-haptic junctions to converge in the center of the IOL, creating a path across the optic. CONCLUSIONS: The optic-haptic junction of the AcrySof one-piece IOL is a point of weakness in the barrier effect of the square-edge IOL design that provides migrating LECs access to the posterior capsule.

Hydrophilic acrylic intraocular lens as a drug-delivery system for fourth-generation fluoroquinolones.

PURPOSE: To evaluate the ability and safety of a hydrophilic acrylic intraocular lens (IOL) as a drug-delivery system for commercially available gatifloxacin and moxifloxacin. SETTING: David J. Apple, MD, Laboratories for Ophthalmic Research, John A. Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, USA. METHODS: Thirty rabbits were divided into 2 similar groups. In Group A (15 rabbits, 30 eyes), hydrophilic acrylic IOLs (C-flex, Rayner Intraocular Lenses, Ltd.) presoaked for 24 hours in commercially available solutions of gatifloxacin 3 mg/mL or moxifloxacin 5 mg/mL were implanted after evacuation of the crystalline lens. Group B (15 rabbits, 30 eyes) had topical preoperative and postoperative cataract prophylaxis with gatifloxacin 3 mg/mL or moxifloxacin 5 mg/mL; IOLs that were not presoaked were also implanted after evacuation of the crystalline lenses. In both groups, aqueous humor samples were taken 4, 8, or 12 hours after IOL implantation (5 eyes at each time point) to determine the antibiotic concentrations. Clinical examinations were performed 24 hours postoperatively. RESULTS: The antibiotic concentrations in Group A (presoaked IOLs) were statistically significantly higher than those in Group B (topical) for both antibiotics in all postoperative samples except moxifloxacin at 12 hours. In both groups, there was no statistically significant difference between the concentrations of the 2 antibiotics. No eye showed signs of clinical toxicity. CONCLUSION: Results show the C-flex IOL is a safe and effective drug-delivery system for fourth-generation fluoroquinolones.

Long-term capsular bag survival without functional lens epithelial cells.

PURPOSE: To evaluate the survival of the capsular bag without the support of functional lens epithelial cells (LECs). SETTING: David J. Apple, MD, Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, USA. METHODS: One hundred slides of cadaver pseudophakic eyes (from 1991 to 2000) stained with hematoxylin and eosin were analyzed to determine the presence of Soemmering's ring, integrity of the capsular bag, fixation configuration of the haptics, and presence and functionality of the LECs. RESULTS: A Soemmering's ring was present in 69% of cases. The capsular bags were intact in 100% of cases. In-the-bag fixation was seen in 44% of cases. In 89% of cases, either no cells or nonfunctional LECs were found. CONCLUSION: Results suggest the capsular bag can survive anatomically without the support of functioning LECs.

Clinical presentation of intraocular lens schisis.

PURPOSE: To analyze the clinical presentation and implications of cavity or schisis formation in the MemoryLens (CIBA Vision) intraocular lens (IOL) optic. SETTING: Eye Department, Red Cross Hospital, Munich, Germany. METHODS: This study was a retrospective chart review and slitlamp photography analysis of IOL schisis. RESULTS: Four patients with IOL schisis were identified and their charts analyzed. Clinically, the schisis presented as a sharply demarcated round structure. The aspect was clear on coaxial illumination, but on tangential illumination the schisis area was opaque. Patients experienced glare, foggy vision, and deteriorated visual function or had no symptoms. One patient lost visual acuity, and the IOL was explanted. CONCLUSIONS: Clinically, IOL schisis was easily differentiated from cases of IOL opacification due to calcification. The clinical implication was not uniform, ranging from no symptoms to great visual disturbance leading to explantation of the IOL. The cause of this complication remains unclear. A possible explanation is the impact of solvent-induced tensile stress on the IOL optic material during the manufacturing process.