Posterior chamber intraocular lens implantation after capsular tear: ultrasound biomicroscopy evaluation.

PURPOSE: To evaluate by ultrasound biomicroscopy (UBM) the exact position of a posterior chamber intraocular lens (PC IOL) implanted above a posterior capsule tear and to correlate the findings with the outcomes and complication rate. SETTING: Department of Ophthalmology, Rabin Medical Center, Petah Tiqva, Israel. METHODS: In a retrospective noncomparative case series, 36 patients (36 eyes) who had extracapsular cataract extraction (ECCE) complicated by capsular tear were evaluated. In all cases, a PC IOL was implanted above the remnant of the capsule without suturing. Ultrasound biomicroscopy was performed to study the exact position of the optic and haptic. The outcomes and complication rate were determined from patient examinations performed during a follow-up of 1 to 6 years. RESULTS: Optic tilt was found in 20 of 36 patients (56%). In 17 patients (47%), both haptics were located in the sulcus. In 15 patients (42%), 1 haptic was observed in the sulcus and 1 in the bag or elsewhere. No correlation was found between the position of the optic and the location of the haptics. Minimal postoperative complications were observed, and only 1 patient required another surgery for a dislocated IOL. CONCLUSION: By UBM, half the patients had optic tilt and more than half the IOLs were not implanted in the sulcus, the intended location.

Pterygium-induced corneal astigmatism.

BACKGROUND: Previous work has suggested an association between increasing size of pterygium and increasing degrees of induced corneal astigmatism. OBJECTIVES: To assess the quantitative relation between pterygium size and induced corneal astigmatism using a computerized corneal analysis system (TMS II) and slit-lamp beam evaluation of pterygium size, and to conclude whether corneal astigmatism is an early indication for surgical intervention. METHODS: We evaluated 94 eyes of 94 patients with unilateral primary pterygium of different sizes, using TMS II and slit-lamp beam measurements of the size of the pterygium (in millimeters) from the limbus to assess parameters of pterygium size with induced corneal astigmatism. Best corrected visual Snellen acuity was performed. RESULTS: Primary pterygium induced with-the-rule astigmatism. Pterygium extending > 16% of the corneal radius or 1.1 mm or less from the limbus produced increasing degrees of induced astigmatism of more than 1.0 diopter. Significant astigmatism was found in 16.16% of 24 eyes with pterygium of 0.2 up to 1.0 mm in size, in 45.45% of 22 eyes with pterygium of 1.1 up to 3.0 mm in size (P < or = 0.0004), and in 100% of 3 eyes with pterygium of 5.1 up to 6.7 mm in size (P = 0.0005). We found that visual acuity was decreased when topographic astigmatism was increased. CONCLUSIONS: When primary pterygium reaches more than 1.0 mm in size from the limbus it induces with-the-rule significant astigmatism (> or = 1.0 diopter). This significant astigmatism tends to increase with the increasing size of the lesion. Topographic astigmatism tends to be improved by successful removal of the pterygium. These findings suggest that early surgical intervention in the pterygium may be indicated when the lesion is more than 1.0 mm in size from the limbus.

Keratoconus and mitral valve prolapse.

PURPOSE: To investigate the prevalence of keratoconus in patients with mitral valve prolapse (MVP). METHODS: Videokeratography was performed in 36 patients (72 eyes) with an echocardiographic diagnosis of MVP, and were compared with 25 controls. All participants underwent slit-lamp examination and completed a medical questionnaire about joint hypermobility, arthralgia, asthma, and allergic reactions. RESULTS: Keratoconus was found in eight eyes (11. 1%) (P =.056) of eight patients (22.2%) (P =.049) in the MVP group and in one eye (2%) of one patient (4%) in the control group. The keratoconus was unilateral and asymptomatic in all cases. Conjunctival papillae were statistical significant higher in the MVP group (P =.015). A statistically significant intergroup difference existed in the presence of an allergic reaction (P =.001), but not in arthralgia, hypermobility of joints, or asthma. CONCLUSION: A borderline important association of MVP with keratoconus and with allergy exists. Patients with mitral valve prolapse complaining of poor vision should be suspected of having keratoconus.

Corneal topographic changes after retinal and vitreous surgery.

PURPOSE: To investigate the topographic changes in the cornea after retinal and vitreous operations. DESIGN: Observational prospective case series. PARTICIPANTS: The study population included 46 patients after vitreoretinal surgery: 11 underwent pneumatic retinopexy, 10 underwent vitrectomy, and 25 underwent scleral buckling procedure. METHODS: The corneal topography was measured by videokeratography with the absolute program and evaluated statistically by a quantitative comparative method, which was developed for this study, for the whole and the central cornea. MAIN OUTCOME MEASURES: The corneal topographic changes were measured in diopters (D), evaluating and comparing the preoperative and postoperative measurements. RESULTS: None of the operative procedures changed the shape of the whole cornea. Vitrectomy induced radial steepening of the central cornea 1.2 to 1.6 D, corresponding to the scleral sutures. Central steepening (average, 2.2 D) was also noted in the first week after circular buckling, but it flattened (average, 1.4 D) after 1 to 3 months. When an additional radial or circumferential buckling element was added to the circular buckle, steepening of the entire cornea and radial steepening of the central cornea (average, 0.6-0.8 D) occurred in the first week and flattened or returned to baseline after 1 to 3 months. There was no correlation between the location of the additional buckling element and the corneal topographic change. CONCLUSIONS: Corneal videokeratography is a useful tool for evaluating the postoperative corneal curvature. It showed that vitreoretinal surgery alters the shape of the cornea when buckling or scleral sutures are used, but pneumatic retinopexy does not.

The effect of tear substitute and silicone oil on re-epithelisation of the cornea.

PURPOSE: An animal model study was conducted to compare the effects of recurrent applications of an artificial cellulosic tear substitute and silicone oil on corneal reepithelisation. METHODS: A controlled wound was inflicted to the corneas of two groups of rabbits; one group was treated with tear substitute (5 eyes), while the other group received silicone oil (5 eyes). The left eye served as the control in both groups (10 eyes). The rate of re-epithelisation was measured at intervals of 6 h until complete wound closure was observed. After complete wound closure, the rabbits were killed and histological examinations were performed. RESULTS: The wounds of eyes treated with tear substitute closed at a statistically significant faster rate (at 24, 44, 80 h; p < 0.05) than those treated with silicone oil or the untreated eyes. At 48 h after re-epithelisation, the eyes treated with tear substitute presented a normal epithelium while the untreated and silicone-treated eyes presented an abnormally structured epithelium. CONCLUSION: This study demonstrates a favourable effect of tear substitute on corneal re-epithelisation in an animal model, in terms of both rate of re-epithelisation and histological aspects of the new epithelium.

A comparison of the effect of hyaluronic acid versus gentamicin on corneal epithelial healing.

PURPOSE: An animal model study was conducted to compare the efficacy of recurrent topical applications of hyaluronic acid and gentamicin ointment for the treatment of noninfected, mechanical corneal erosions. METHODS: An artificial, controlled wound of identical size and depth was inflicted to the corneas of three groups of rabbit eyes in order to measure their healing rates. One group was treated with hyaluronic acid (10 eyes) while the second group received gentamicin ointment (10 eyes). The third group remained untreated and served as the control (10 eyes). The rate of re-epithelisation was measured at 8-h intervals until complete re-epithelisation was observed. After complete wound closure, the rabbits were killed, and comparative histological examinations were performed. RESULTS: Rabbit eyes treated with hyaluronic acid showed a significantly enhanced rate of epithelial defect closure compared with untreated eyes and a similar rate to that achieved with gentamicin ointment. In the eyes treated with hyaluronic acid a normal, multilayered epithelium was observed 48 h after complete healing, whereas the gentamicin-treated eyes showed an imperfectly layered epithelium, with irregularity of the cuboidal cells. CONCLUSION: While both hyaluronic acid and gentamicin enhance corneal epithelial healing at comparable rates, our study suggests that hyaluronic acid may have a more favourable effect on the structure of the healing epithelium, and can offer an alternative mode of therapy for non-infectious corneal erosions.

The development and progression of diabetic retinopathy in type I diabetic patients: a cohort study.

To describe the course and risk factors for development and progression of retinopathy, we studied a cohort of 333 Israeli Jewish patients with Type 1 (insulin-dependent) diabetes mellitus. The median age at diagnosis was 9.5 (range 0.04-26.2) years and the median duration of follow-up was 14 (range 1.6-30) years. Evaluation of both retinae was performed yearly since referral and HbA1 values were tested every 3 months since 1978. During a follow-up of 4070 patient-years, 162 patients developed non-proliferative retinopathy. The median retinopathy-free interval was 14.9 years and after 30 years all patients were affected. Pre-pubertal duration of diabetes was relevant. Independent and significant risk factors for early onset of non-proliferative retinopathy were: poor cumulative glycaemic control (median retinopathy-free interval in the 1st vs 4th quartiles of mean HbA1 values over all years: 18.0 vs 12.5 years, p = 0.0001); onset of diabetes during or after puberty (median retinopathy-free interval in patients with onset of diabetes before, during or after pubescence: 16.3, 13.2 and 14.0 years, respectively, p = 0.0001); and non-Ashkenazi Jewish origin (median retinopathy-free interval 15.8 years in Ashkenazi vs 14.0 in non-Ashkenazi patients, p = 0.0004). Of 162 patients with non-proliferative retinopathy, progression to proliferative retinopathy occurred in 37, during 707 patient-years. The first event of proliferative retinopathy was diagnosed within the 1st year after non-proliferative retinopathy evolved, and at 6.3 years since onset of non-proliferative retinopathy 75% of the patients were still free of proliferative changes. Risk factors significantly and independently associated with an early progression to the proliferative stage were: poor glycaemic control in the last 3 years prior to the development of proliferative retinopathy and non-Ashkenazi Jewish origin. All patients in the 4th quartile of HbA1 values were affected by proliferative retinopathy within 11.6 years after onset of non-proliferative retinopathy.

Effects of the picosecond neodymium:YLF laser on poly(methyl methacrylate) intraocular lenses during experimental posterior capsulotomy.

We evaluated the effect of the neodymium:YLF picosecond laser on intraocular lenses (IOLs) during experimental posterior capsulotomy and established the minimum damage threshold for lathe-cut poly(methyl methacrylate) (PMMA) IOLs. Single-piece, biconvex, lathe-cut PMMA lenses were placed in a model eye chamber against a latex membrane with a central area of lens-capsule touch. Energy levels from 40 micro J to 360 microJ pulse (0.4 mJ to 3.6 mJ) with a 0.5 mm line and a spot pattern were tested using different focal offsets. Threshold damage level was determined under the scanning electron microscope after observing the minimal energy level that did not cause damage to or pits in the IOLs. Lenses were then analyzed for size and type of damage. The 0.5 mm line pattern at 160 microJ using 350 microns offset was safe and effective for posterior capsulotomy in vitro. spot pattern caused IOL damage in the form of small pits at much lower energy levels of 80 microJ using 400 microns offset than the line pattern.

Topical diclofenac following excimer laser: effect on corneal sensitivity and wound healing in rabbits.

BACKGROUND: Diclofenac is a nonsteroidal antiinflammatory drug (NSAID) that is widely used systemically and topically. We studied the effect of diclofenac on corneal reepithelialization and corneal sensitivity after excimer laser treatment in rabbits. METHODS: Twelve New Zealand white rabbits were divided into four groups (A, B, C, and D). Groups A and B received diclofenac four times and eight times daily, respectively, following a central 5-millimeter epithelial debridement. Groups C (control) and D (diclofenac four times daily) underwent excimer laser ablation (30-micrometer depth) following manual debridement. Wound healing was compared between groups A and B and groups C and D. Sensitivity was recorded preoperatively and postoperatively 1 to 5 and 14 days in groups C and D until normal values were reestablished. RESULTS: Total time for corneal wound healing and epithelial migration rates was not delayed in any group receiving diclofenac (A, B, and D). Sensitivity after laser ablation reached a minimum of 15% to 20% in both groups C and D by day 2 and returned to normal (100%) by day 8. The decrease in sensitivity between group C, the controls, and group D, receiving diclofenac four times daily, was not statistically significant. CONCLUSIONS: Diclofenac can be used up to eight times daily in the rabbit without causing changes in corneal wound healing or epithelial migration rate. There was no significant, long-term reduction of sensitivity, and recovery was not affected by diclofenac.

Corneal sensitivity and nerve regeneration after excimer laser ablation.

We studied the recovery of corneal sensitivity and corneal regeneration after excimer laser and manual epithelial debridement. The corneal epithelia of right eyes of New Zealand white rabbits (n = 21) were manually debrided and the corneal epithelia of the left eyes were ablated with the excimer laser (47 mm depth, 5 Hz, and 160 mJ/cm2). The relative density of innervation on the intraepithelial layer was measured using gold chloride staining and light microscopy. Wound healing and corneal sensitivity also were observed. Laser-ablated corneal sensitivity increased rapidly to a normal level by day 5, then increased gradually and reached a maximum at day 42. It remained elevated until 126 days, then returned to normal at 210 days. There were significant differences in the recovery of sensitivity after excimer ablation and manual epithelial removal. At day 35, relative density of innervation in the intraepithelial layer treated with excimer laser ablation was significantly higher than that treated with manual debridement. We observed a correlation between increased sensitivity and increased nerve density after excimer ablation. Compared with manual debridement, laser treatment resulted in an increase in networks of axons with terminal endings. This may not be the only factor correlating directly with hypersensitivity after corneal debridement, but it may indicate a quicker recovery route by using a presurgical manual debridement technique.

Handling punctate keratitis resulting from systemic cytarabine.

A young patient with acute myelogenous leukemia was treated with high-dose cytarabine (3.0 g/m2 every 12 hours). After five days of treatment, he developed severe photophobia and decreased visual acuity. On examination, progressive punctate keratitis was found. We discuss the mechanism of the cytarabine-induced corneal toxicity and the prophylactic use of topical corticosteroids.

Risk factors for development of diabetic nephropathy and retinopathy in Jewish IDDM patients.

Risk factors associated with diabetic microvascular complications, with special reference to ethnic origin, were looked for in 231 young Jewish insulin-dependent diabetes mellitus (IDDM) patients with duration of diabetes greater than or equal to 10 yr. Median age at diagnosis of diabetes was 9.2 yr (range 0.04-26.2 yr), and median duration of the disease was 15.3 yr (range 10.0-37.2 yr). Sixty-three percent of the patients were Ashkenazi Jews, and 37% were non-Ashkenazi Jews. HbA1 was evaluated every 3 mo in the last 10 yr of follow-up, and albumin excretion rate was tested in three 24-h urine collections. Direct and indirect ophthalmoscopy was performed every year since diagnosis of diabetes, and if retinal pathology was suspected, color photographs were taken. Microalbuminuria was detected in 31% and macroalbuminuria in 7% of the patients. Nonproliferative and proliferative retinopathy was found in 44 and 12% of the patients, respectively. On logistic regression analysis, two variables were significantly and independently associated with diabetic nephropathy--non-Ashkenazi origin and mean HbA1 values over the first 5 of 10 yr of follow-up. Variables significantly and independently related to diabetic retinopathy were non-Ashkenazi origin, mean HbA1 values over the last 10 yr of follow-up, and duration of diabetes. Because non-Ashkenazi Jews in Israel are of lower socioeconomic status than Ashkenazi Jews, we stratified our patients according to their socioeconomic parameters, median HbA1 values, and duration of diabetes. Non-Ashkenazi patients were at a higher risk to develop complications in all strata.(ABSTRACT TRUNCATED AT 250 WORDS)

Massive pseudophakic pigment dispersion associated with an iris nevus.

A 67-year-old woman examined 12 months following extracapsular cataract extraction had a massive pseudophakic pigment dispersion associated with diffuse corneal epithelial edema, mild uveitis, and secondary glaucoma. She underwent penetrating keratoplasty following removal of a posterior chamber intraocular lens (IOL), anterior vitrectomy, capsulectomy, and iris biopsy. Histopathologic examination revealed a pigmented iris nevus and signs of iris erosion by the IOL loop. Because 3 months later the eye developed streptococcal endophthalmitis and had to be eviscerated, we had the opportunity to examine the eye contents; we found no evidence of phakoanaphylactic uveitis.

The effect of sodium hyaluronate on the corneal epithelium. An ultrastructural study.

The effect of sodium hyaluronate (NaHa) 1% and 0.1% was studied on 14-day chick embryo corneal epithelium by scanning electron microscopy. It was found that NaHa 1% or 0.1% had no toxic effects on the chick corneal epithelium and the normal architecture of the cells and the morphology of the microvilli was well preserved. A combination of NaHa 0.1% and benzalkonium chloride (BAK) 0.01% reduced the toxic effect of BAK on the surface corneal epithelium. NaHa 0.1% provided a better protection of the corneal epithelium against dryness than hydroxyethylcellulose (HEC) 0.1% or phosphate buffer saline (PBS).

Formation of lentoids from retina gliocytes: ultrastructural study.

In primary monolayer cultures of dispersed neural retina cells from 13-day chick embryo, gliocytes (Müller glia cells) multiply and rapidly change into a lentoidal (lens-like) phenotype. They express lens proteins, including MP26 (a lens plasma-membrane antigen) and ultra-structurally appear to resemble lens cells. A significant aspect of this modification is that the glia-derived lentoidal cells no longer display contact-affinity for neurons but become preferentially adhesive to each other; in aggregates, they assemble into compact lentoids. A likely explanation for this change in cell affinities is that the modified gliocytes express little or no R-cognin, a retinal cell-surface antigen implicated in mutual recognition and adhesion of retina cells. Although lentoidal cells express MP26, a gap-junction component in the lens, no gap junctions could be found in the lentoids.