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PubMed2002

Environmental temperature and cataract progression in experimental rat cataract models.

PURPOSE: To clarify whether or not ambient temperature relates to cataract development or the progression of cataract formation. MATERIALS AND METHODS: 36 Brown Norway rats were divided into two groups, a high-temperature (35 +/- 2 degrees C, H = high) breeding group and a regular-temperature (24 +/- 2 degrees C, L = low) group. Each group was further divided into an experimentally induced diabetic cataract subgroup (50 mg/kg streptozotocin, DM), an ultraviolet B exposure-induced cataract subgroup (200 mJ/cm2, UV), and a normal control subgroup (C = control). Slit-lamp microscopy and an anterior image analysis system (EAS-1000) were used to evaluate lens changes. RESULTS: Both the HC and HUV groups in the 35 degrees C conditions showed higher light scattering than that of the 24 degrees C conditions (LC and LUV) 3 weeks after the start of the experiment. Nine weeks after the start of the experiment, all the rats of the UV subgroups (HUV and LUV) developed anterior subcapsular cataract. The temperature did not have much influence on the progression of the UV-B-induced cataract. From 18 days after the start of the experiment, the HC subgroup showed a wider light scattering area than the LC. An increase in abnormal nuclear scattering light in the crystalline lens of group HC was found in 9 weeks after the start of the experiment, and at the end of the experiment (78 weeks later), dense abnormal nuclear light scattering was found including the prenuclear area. In contrast, the HDM group in the 35 degrees C conditions showed slower cataract progression than that of the LDM group at 24 degrees C room temperature. CONCLUSIONS: Although further experiments are necessary before we can draw any conclusions about temperature and nuclear changes, paying attention to the effects of temperature on the lens is worthwhile.

Animals↗
PubMedDate not supplied

Attenuation and delay of diabetic cataracts by antioxidants: effectiveness of pyruvate after onset of cataract.

Cataract is one of the most significant vision-impairing complications of diabetes. The present study examined the feasibility of inhibiting cataract formation by treatment with pyruvate, a metabolite known to effectively scavenge reactive species of oxygen and inhibit protein glycation, both known to be involved in the genesis of diabetic cataracts. In addition, pyruvate stimulates tissue metabolism, which is depressed with the onset of cataract formation. The objective of our experiments was to determine if this compound could be effective in offsetting the progress of cataract, specifically if administered after the diabetes-induced lens changes have begun, as opposed to the previous reports wherein it has been reported to delay cataract formation if administered prophylactically with the immediate onset of diabetes. Diabetes was induced by intraperitoneal administration of streptozotocin to mice. Lens transparency was assessed by slit lamp examination and its photography. ATP was determined enzymatically by reacting it with luciferin-luciferase mixture and measuring the fluorescence intensity. The findings described herein are in accordance with this possibility. The incidence of cataract in the group of diabetic animals, where treatment with pyruvate was initiated after the initial lens changes set in, was significantly lower at all times of observation in comparison to the untreated diabetic group. In addition, the severity of opacities in the pyruvate-treated group, when present, was much minor, the transparency of these cases being close to that in the control animals. The ophthalmic findings are supported biochemically by ATP levels, which were significantly higher in the pyruvate group in comparison to the untreated group. The present findings emphasize the clinical usefulness of initiating treatment with anti-oxidants and metabolic agonists even when the lens changes are detected at the time of the diabetes diagnosis. The latter usually comes much later than the onset of visual aberrations. Prophylaxis is not an absolute requirement.

Adenosine Triphosphate↗
PubMed1997

Possible mechanism of exacerbating cataract formation in cataractous human lens capsules induced by systemic hypertension or glaucoma.

To clarify the role of the lens capsule in cataract formation, changes in the protein conformational structure of immature cataractous lens capsules from patients with systemic hypertension or glaucoma have been investigated, as compared to normal lens capsules. The protein secondary structure and composition of these capsular samples were determined using Fourier transform infrared microspectroscopy with second-derivative, deconvolution and curve-fitting methods. We found that the composition of both random coil and beta-type (beta-sheet and beta-turn) structures in the immature cataractous human lens capsules was increasingly induced by systemic hypertension or glaucoma, but alpha-helix content clearly decreased, leading to the alteration of protein conformational structures in lens capsules. A possible pathway of cataract formation exacerbated by systemic hypertension or glaucoma is discussed. According to the results, we propose that systemic hypertension or glaucoma induce changes in the protein conformational structures of the lens capsule, then cause alteration of membrane transport and permeability for ions, and finally increase intraocular pressure, resulting in the exacerbation of cataract formation. The effect on the conformational structure of cataractous human lens capsules is more pronounced for systemic hypertension than for glaucoma. The present study implies that systemic hypertension or glaucoma can exacerbate cataract formation in senile patients by modifying the protein secondary structures in the lens capsule.

Adult↗
PubMed1998

Synthesis of 4-hydroxy-3(2H)-furanone acyl derivatives and their anti-cataract effect on spontaneous cataract rats (ICR/f).

4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) and 2(or 5)-ethyl-4-hydroxy-5(or 2)-methyl-3(2H)-furanone (EHMF) are known to inhibit cataract development in spontaneous cataract rats (ICR/f). Forty-five acylated hydroxyfuranone derivatives were designed and synthesized for an anti-cataract test, and their hydrophobic constants were also tested. Among these derivatives, 2,5-dimethyl-4-pivaloyloxy-3(2H)-furanone (HDMF pivalate) exerted a marked protective effect against the development of cataract in a galactose-induced model using cultured rat lens (in vitro). When tested on an ICR/f cataract model (in vivo), HDMF pivalate showed more significant inhibition of cataract development than parent compound HDMF. This derivative is more lipophilic than HDMF, so that HDMF pivalate can penetrate the cornea more easily than HDMF. The inhibition of cataract development by HDMF converted from HDMF pivalate is supported by the fact that HDMF was observed in the lens of ICR/f rats treated with HDMF pivalate.

Acylation↗
PubMed2005

Manual small incision cataract surgery in eyes with white cataracts.

PURPOSE: To assess the safety and efficacy of Manual Small Incision Cataract Surgery (MSICS) in cases of white cataract with the use of trypan blue as an adjunct for performing continuous curvilinear capsulorthexis (CCC). MATERIALS AND METHODS: Prospective observational study on 100 consecutive eyes of 100 patients with white cataract who had undergone MSICS with trypan blue assisted CCC. The nucleus was prolapsed into anterior chamber by using a sinskey hook and extracted out of the eye using irrigating vectis. Intraoperative and postoperative findings (according to OCTET classification) as well as postoperative visual outcomes were used as main measures to report the safety and efficacy of the surgery. RESULTS: Of the 100 eyes, 16 had intumescent, 67 had mature and 17 had hypermature cataract. Intraoperatively CCC was incomplete in 4 eyes (4%) and had to be converted to canopener capsulotomy. None of the eyes had posterior capsular rupture or zonular dialysis and no eyes were converted to conventional Extra Capsular Cataract Extraction (ECCE). Postoperatively, 6 eyes (6%) developed corneal oedema with >10 Descemets folds and 7 eyes (7%) had corneal oedema with CONCLUSION: In developing countries like India where phacoemulsification may not be affordable to a majority of those requiring cataract surgery, MSICS proves to be a safe and efficacious alternative for white cataracts especially with the adjunctive use of trypan blue dye.

Adult↗
PubMed1991

Cataract risk factors: blood level of antioxidative vitamins, reduced glutathione and malondialdehyde in cataractous patients.

Since many years experimental evidences have suggested an association between nutrition and lens opacities. A dietary deficiency of antioxidants and reactive oxygen scavengers may be involved in the pathogenesis of the "idiopathic" human senile cataract, as it has been demonstrated in some experimental cataracts. We tested the levels of ascorbic acid (vit. C), alpha-tocopherol (vit. E), reduced glutathione (GSH) and malondialdehyde (MDA) in the plasma or in the red blood cells (RBC) of 42 patients who were affected by surgically significant cataract and of 40 age-matched controls. Plasma vit. C mean level was 4.46 gamma/ml in cataracts and 4.62 gamma/ml in controls, while vit. E level was 7.70 and 7.09 gamma/ml respectively. RBC GSH was found to be 342 gamma/ml in cataracts and 346 in controls, while the MDA content was 4.06 picoMol/ml and 4.08 picoMol/ml respectively. The level of each tested nutrient or metabolite was not found to be statistically different between cataractous patients and controls, nor any significant trend was found to be present when the nutrients and metabolites were correlated to each other. Our results do not support the hypothesis of a nutritional deficiency in human senile cataracts. However, a defect in the antioxidative metabolism pathways could be present either systemically or at lens level.

Age Distribution↗
PubMed2005

CRYGD gene analysis in a family with autosomal dominant congenital cataract: evidence for molecular homogeneity and intrafamilial clinical heterogeneity in aculeiform cataract.

PURPOSE: To present a previously unreported four generation affected Mexican pedigree with congenital hereditary aculeiform cataract caused by a mutation in the gammaD-crystallin (CRYGD) gene. METHODS: A four generation family with 14 available members of whom 8 were affected was analyzed. Interventions included complete ophthalmological examination, cataract phenotype characterization, PCR amplification, and automated DNA sequencing of the 2 exons and exon/intron junctions of the CRYGD gene. RESULTS: A heterozygous missense mutation consisting of a G to A transition at nucleotide position 411 in exon 2 that predicts an Arg to His replacement in residue 58 (R58H) of the CRYGD protein was demonstrated. Intrafamilial clinical heterogeneity was observed as one affected member exhibited a coral-like cataract. CONCLUSIONS: The R58H mutation described in this Mexican family is identical to that demonstrated previously in three unrelated families with aculeiform cataract, suggesting that this type of cataract has a specific molecular basis represented by the Arg to His change at residue 58 of CRYGD. However, intrafamilial clinical heterogeneity associated with this mutation can occur as evidenced by the identification of a subject in this family exhibiting a coral-like cataract, a phenotype classically distinguished from aculeiform cataract. To our knowledge, this is the first example of phenotypic heterogeneity associated with the Arg 58 His CRYGD mutation.

Cataract↗
PubMed1984

Clinical classification of after-cataract following planned extracapsular cataract extraction.

A total of 100 eyes underwent planned extracapsular cataract extraction and were followed more than three months with a mean follow-up period of 12 +/- 8 months. After-cataract was found in 72 eyes. The after-cataract was classified by slit-lamp microscopy into two types, the remnant type and the proliferative type. The former type was due to remains of the lens materials and was present immediately after the surgery: this type was divided into veil-like and Soemmering forms. The proliferative type developed after a period following surgery and was divided into fibrous form and Elschnig form. The fibrous form was thought to be due to fibrous proliferation of the lens epithelial cells, since it was seen at or to originate from the sites of adhesion of the anterior and posterior capsules. The Elschnig form consisted of Elschnig's pearls and was divided into progressive and localized subforms. The former subform was seen more frequently in young patients than the latter subform. The incidences of the above types and forms of the after-cataract were determined. Impairment of the visual acuity due to after-cataract was seen in the proliferative type and was found in 7 eyes. A fluorophotometric study to evaluate the function of the blood-aqueous barrier was carried out in 7 patients with the presence of after-cataract and in 11 patients with no or subtle after-cataract. No difference was found in the barrier function between the two groups.

Adolescent↗
PubMed1996

Combined cataract and glaucoma procedures using temporal cataract surgery.

PURPOSE: To evaluate whether separating the procedures in a combined procedure by performing a temporal cataract incision and superior trabeculectomy induces the lower astigmatism of a temporal cataract incision without sacrificing intraocular pressure (IOP) control. SETTING: EyeSight Associates, Warner Robins, Georgia. METHODS: This study evaluated 50 consecutive eyes receiving a superior cataract incision with a superonasal trabeculectomy and 65 eyes receiving a temporal cataract incision with a superonasal trabeculectomy. RESULTS: After 3 months, a substantially greater proportion of temporal incision cases had controlled IOP without medication. A substantially higher proportion in the superior incision group had uncontrolled IOP at each time period. Mean surgically induced cylinder was higher in the superior incision group at every time period. The superior group had early with-the-rule mean induced cylinder that decayed to against-the-rule, with a mean induced cylinder with keratometry at the final available visit (more than 3 months) of -1.01 diopter (D). The temporal group started with a negligible induced cylinder (-0.13 D) that drifted slightly with the rule to a final mean induced cylinder of +0.49 D. At the last visit, 31% in the superior incision group and 57% in the temporal incision group had an uncorrected visual acuity of 20/40 or better, and 72% and 94%, respectively, had a best corrected acuity of 20/40 or better. CONCLUSION: Separating the cataract and glaucoma procedures frees the surgeon to use newer astigmatically neutral techniques for the cataract incision.

Aged↗
PubMed2006

The Antioxidants in Prevention of Cataracts Study: effects of antioxidant supplements on cataract progression in South India.

AIM: To determine if antioxidant supplements (beta carotene and vitamins C and E) can decrease the progression of cataract in rural South India. METHODS: The Antioxidants in Prevention of Cataracts (APC) Study was a 5 year, randomised, triple masked, placebo controlled, field based clinical trial to assess the ability of interventional antioxidant supplements to slow cataract progression. The primary outcome variable was change in nuclear opalescence over time. Secondary outcome variables were cortical and posterior subcapsular opacities and nuclear colour changes; best corrected visual acuity change; myopic shift; and failure of treatment. Annual examinations were performed for each subject by three examiners, in a masked fashion. Multivariate modelling using a general estimating equation was used for analysis of results, correcting for multiple measurements over time. RESULTS: Initial enrolment was 798 subjects. Treatment groups were comparable at baseline. There was high compliance with follow up and study medications. There was progression in cataracts. There was no significant difference between placebo and active treatment groups for either the primary or secondary outcome variables. CONCLUSION: Antioxidant supplementation with beta carotene, vitamins C and E did not affect cataract progression in a population with a high prevalence of cataract whose diet is generally deficient in antioxidants.

Adult↗
PubMed2003

Extracapsular cataract surgery compared with manual small incision cataract surgery in community eye care setting in western India: a randomised controlled trial.

AIM: To study "manual small incision cataract surgery (MSICS)" for the rehabilitation of cataract visually impaired and blind patients in community based, high volume, eye hospital setting; to compare the safety and effectiveness of MSICS with conventional extracapsular cataract surgery (ECCE). METHODS: In a single masked randomised controlled clinical trial, 741 patients, aged 40-90 years, with operable cataract were randomly assigned to receive either MSICS or ECCE and operated upon by one of eight participating surgeons. Intraoperative and postoperative complications were graded and scored according to the Oxford Cataract Treatment and Evaluation Team recommendations. The patients were followed up at 1 week, 6 weeks, and 1 year after surgery and their visual acuity recorded. RESULTS: This paper reports outcomes at 1 and 6 weeks. 706 of the 741(95.3%) patients completed the 6 week follow up. 135 of 362 (37.3%) of ECCE group and 165 of 344 (47.9%) of MSICS group had uncorrected visual acuity of 6/18 or better after 6 weeks of follow up. 314 of 362 (86.7%) of ECCE group and 309 of 344 (89.8%) of MSICS group had corrected postoperative vision of 6/18 or better. Four of 362 (1.1%) of ECCE group and six of 344 (1.7%) of MSICS group had corrected postoperative visual acuity less than 6/60. There were no significant differences between the two groups for intraoperative and severe postoperative complications. CONCLUSION: MSICS and ECCE are both safe and effective techniques for treatment of cataract patients in community eye care settings. MSICS needs similar equipment to ECCE, but gives better uncorrected vision.

Adult↗
PubMed1996

The pattern of cataract and the postoperative outcome of cataract extraction in Ethiopian leprosy patients as compared to nonleprosy patients.

Cataract is a blinding disease occurring all over the world. One of the causes of cataract is leprosy. Sixty leprosy and 100 nonleprosy patients were assessed and underwent intracapsular cataract extraction. Leprosy patients with cataract were much younger than nonleprosy patients. The leprosy group had a significantly higher rate of complications and this was seen more in paucibacillary cases. There was a higher rate of visual disability in the leprosy group than in the nonleprosy group. Cataract was seen in younger patients in the leprosy group. This raised the possibility of leprosy being the cause of the cataract. The leprosy group consisted mostly of multibacillary cases, however unlike in other studies the rate of complications tended to be higher in the paucibacillary group. There were no preoperative findings that correlated with a low postoperative intraocular pressure.

Cataract↗
PubMed2006

[Evolution of secondary pseudoexfoliative glaucoma after cataract surgery in patients with cataract-glaucoma combination].

PURPOSE: To assess the effects of the cataract surgery on the evolution of the secondary open angle glaucoma (SOAG) in patients with pseudoexfoliative syndrome (PEX) that present the association cataract--SOAG. METHODS: A prospective study on 2 years on a group of 12 eyes with PEX syndrome presenting the association cataract-secondary open angle glaucoma, that have been operated by phacoemulsification + PC IOL, without intra-operator complications. We have monitored the effects of the cataract surgery on the evolution of the glaucomatous disease, evaluated by: monitoring of the IOP dynamics, the analysis of the visual field defects and the aspect of the FO, the evolution of the visual acuity and the morphology of the specific changes of PEX. The analysed group has been compared with a control group (5 eyes) presenting the association cataract--POAG, operated by phacoemulsification by the same surgeon. We have used the SPSS programme for statistical analysis. RESULTS: In the follow-up period we have observed almost similar evolutions of the IOP dynamic, but we obtained in PEX group statistically significant lowering of the IOP than in the control group. In PEX group the papillo-perimetric results have presented significantly different characteristics than in the control group, without having an influence on the visual acuity. CONCLUSIONS: Although the cataract extraction has produced in both groups, on a medium follow-up, an IOP decrease from the pre-operator values, the glaucomatous disease in PEX patients, probably because of other specific risk factors, continues to progress.

Adrenergic beta-Antagonists↗
PubMed1996

The results of ab interno laser thermal sclerostomy combined with cataract surgery versus trabeculectomy combined with cataract surgery 6 to 12 months postoperatively.

BACKGROUND AND OBJECTIVE: When cataract surgery and glaucoma surgery are combined, the theoretical advantages of pressure control, removal of the visual impairment, and protection against an increase in intraocular pressure (IOP) in the immediate postoperative period are gained. The authors' objective was to determine whether ab interno laser thermal sclerostomy (LTS) combined with cataract surgery would be as effective as trabeculectomy combined with cataract surgery. PATIENTS AND METHODS: Ab interno LTS was compared with trabeculectomy, retrospectively, for patients who had undergone combined cataract and glaucoma surgery. RESULTS: There was no significant difference in the numbers of patients using no medications or fewer medications at 6 and 12 months. There was a greater reduction in IOP in the LTS group. CONCLUSIONS: LTS may be better than trabeculectomy in combined cataract and glaucoma surgery because it reduces the IOP more. Compared with trabeculectomy, LTS is simpler to perform and adds less operating time to cataract surgery. Continued follow-up is recommended.

Adult↗
PubMed1979

Posterior subcapsular cataracts: histopathologic study of steroid-associated cataracts.

Long-term steroid therapy is associated with production of a posterior subcapsular cataract (PSC). Five steroid-associated cataractous lenses were studied, using light, scanning, and transmission electron microscopy. Anterior, equatorial, and posterior regions were examined. Findings were compared with five age-matched senile PSCs and five nuclear cataractous lenses with no cortical opacities. The posterior polar region of steroid-associated cataractous lenses consists of (1) a superficial zone of liquefaction and (2) a deep zone of segmentally swollen lens fibers. Nucleated lens fibers are present in posterior cortical regions. Cytoplasm at knob and socket junctions had become lucent and plasma membranes were disappearing, leaving empty spaces. Laminated membranous configurations were seen. Although the same basic histopathologic abnormalities were found in steroid-associated cataracts and in nonsteroid senile PSCs, it is their organization and localization that may be the distinguishing characteristics of the steroid-associated cataract.

Adrenal Cortex Hormones↗
PubMed1990

Late onset hereditary cataract of the emory mouse. A model for human senile cataract.

The late onset cataract of the Emory mouse has appealed to many investigators as a useful animal model for human senile cataract. It has been the subject of about 15 publications, beginning in 1982. These have explored many features, including histology, chromatography and isoelectric focusing of the crystallins, enzyme profiles, amino acid and ion transport, membrane studies including changes in MP24 and MP26, analysis for a number of biochemical constituents, and its use as an assay system for testing the effect of anticataractogenic drugs and dietary restriction. These investigations have not uncovered a single metabolic lesion marked enough to be considered an important cause of this cataract. There is some evidence that the effect of oxidation may be a major factor; likewise there is evidence for faulty protein synthesis. In many cases, the changes in cataractogenesis appear to be accelerated aging changes. For this reason, any study of this cataract must employ age-matched controls of the cataract-resistant strain. A recent discovery is the finding that many earlier studies used a mixture of both early and late-onset forms, accounting for the wide variability in analytical results. The two substrains may have somewhat different applications in cataract research. Thus, the availability of these two substrains should extend the usefulness of this animal model.

Animals↗
PubMed1994

Incidence and progression of cortical, nuclear, and posterior subcapsular cataracts. The Italian-American Cataract Study Group.

A total of 1,399 persons, between 45 and 79 years of age, who had been identified in a clinic-based case-control study were invited to participate in a follow-up study. The follow-up study was designed to estimate the incidence and progression of cortical, nuclear, and posterior subcapsular cataracts and to evaluate the usefulness of the Lens Opacities Classification System II in a longitudinal study. Survival analyses were performed on 1,193 persons with at least three visits, by using data obtained from Zeiss slit-lamp and Neitz retroillumination lens photographs. The three-year cumulative incidence for persons age 65 to 74 years (the largest age group) was 18%, 6%, and 6% for cortical, nuclear, and posterior subcapsular cataracts, respectively. Progression was much higher than incidence for each type of opacity. Regression, which probably comes mostly from misclassification in the gradings, was modest for cortical and nuclear cataracts but was sizeable for posterior subcapsular cataracts. Patient age, baseline lens status, cataract grading system, definition of change, and analytic methodology can have important effects on estimates of cataract incidence and progression.

Aged↗
PubMed1992

National outcomes of cataract extraction. Increased risk of retinal complications associated with Nd:YAG laser capsulotomy. The Cataract Patient Outcomes Research Team.

PURPOSE: The authors studied 57,103 randomly selected Medicare beneficiaries who underwent extracapsular cataract extraction in 1986 or 1987 to determine the possible association between performance of neodymium (Nd):YAG laser capsulotomy and the risk of subsequent retinal break or detachment. METHODS: Cases of cataract surgery were identified from Medicare claims submitted in 1986 and 1987 and were followed through the end of 1988. Episodes of cataract surgery, posterior capsulotomy, and retinal complications were ascertained based on procedure and diagnosis codes listed in physician bills and hospital discharge records. Lifetable and Cox's proportional hazards models were used to analyze the risk of retinal detachment or break in patients undergoing and not undergoing capsulotomy during the period of observation. RESULTS: Of the 57,103 persons identified as having undergone extracapsular cataract extraction in 1986 or 1987, 13,709 subsequently underwent Nd:YAG laser capsulotomy between 1986 and 1988. A total of 337 persons had aphakic or pseudophakic retinal detachments between 1986 and 1988 and an additional 194 underwent repair of a retinal break. Proportional hazards modeling shows a 3.9-fold increase in the risk of retinal break or detachment among those who underwent capsulotomy (95% confidence interval: 2.89 to 5.25). Younger patient age, male sex, and white race also were associated with increased risk of retinal complications after extracapsular cataract extraction. CONCLUSION: The authors conclude that there is a statistically significant increase in the risk of retinal detachment or break in those patients who undergo capsulotomy after cataract extraction. Therefore, capsulotomy should be deferred until the patient's impairment caused by capsular opacification warrants the increased risk of retinal complications associated with performance of capsulotomy.

Aged↗