Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CATARACT”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33Linked to original sources
PubMed1998

Effect of cataract surgery on ocular axial length elongation in young children.

PURPOSE: To evaluate the influence of cataract surgery on eyes of children between 1-5 years old. MATERIALS AND METHODS: Forty-seven cases of pediatric cataract, including 31 cases of bilateral congenital cataract and 16 cases of unilateral posttraumatic cataract, were retrospected. Of the 31 cases of congenital cataract, 19 cases (group 1) had undergone cataract extraction with intraocular lens (IOL) implantation, 12 (group 2) had undergone cataract extraction without IOL implantation. Each of them had their two eyes operated separately at an interval of 1 year or longer. Of the 16 cases of posttraumatic cataract, 6 (group 3) had undergone cataract extraction with IOL implantation and 10 (group 4) had undergone cataract extraction without IOL implantation. Mean age at the time of interested surgery was 2.9 years (range from 1.1 to 5.1 years). Ocular axial length of both eyes measured by A-scan ultrasonography before and after the surgery of the earlier operated eye in the congenital groups and the operated eye in the post-traumatic groups was recorded. The elongation of axial length of the earlier operated eye in the congenital groups and the operated eyes in the posttraumatic groups of each case were compared with that of the fellow eye statistically with paired t-test. RESULTS: The mean follow-up was 2.6 years (ranged from 1.0 to 6.4 years). In all the 4 groups, the elongation of axial length between the earlier operated eye and later operated eye in the congenital groups and between the operated and unoperated eyes in the posttraumatic groups of each case was not significantly different (p > 0.05). CONCLUSION: Cataract surgery, either extraction with or without IOL implantation, did not retard axial elongation in children above 1 year old.

Age Factors↗
PubMed2005

[Survey surgery delay for age-related cataract by a questionnaire in Qingdao].

OBJECTIVE: To investigate the reasons why patients suffering hypermature or mature cataract in the urban Qingdao city do not undergo cataract surgery in time. METHODS: 104 inpatients with mature or hypermature age-related cataract were interviewed with a questionnaire concerning medical, economic, social and psychological factors. RESULTS: The factors related with the surgery delay were medical factor 44.3%, economic factor 7.1%, social factor 20.7% and psychological factor 27.9%. In the lists of detailed reasons, 'cataract being not mature' ranked the first (17.1%), 'unaware of cataract' (14.3%) and "still able to see something" (10.0%) were followed. The history of cataract surgery, age, degree of education, the knowledge of cataract and individual income all played some roles in the delay of cataract surgery (P < 0.05). CONCLUSIONS: It is important to educate people about cataract knowledge and clarify the role of cataract surgery in order to convince patients to have cataract surgery done in time and improve life quality.

Age Factors↗
PubMed1998

Early treatment of congenital unilateral cataract minimizes unequal competition.

PURPOSE: Dense congenital unilateral cataracts may compromise visual development through visual deprivation and biased interocular competition, whereas dense congenital bilateral cataracts compromise visual development primarily through visual deprivation alone. Differences in sensory deficits between the two patient groups with these disorders may reflect the specific effects of unequal competition. To determine whether early treatment (at <8 weeks of age) minimizes the adverse effects of unequal competition, grating acuity deficits during the immediate posttreatment period and contrast sensitivity deficits at 6 to 8 years of age were assessed in 29 children with histories of dense congenital unilateral or bilateral cataracts who had had treatment between 1 and 8 weeks or 12 and 30 weeks. All children maintained good to excellent compliance with optical correction and occlusion therapy. METHODS: Grating acuity was measured using a two-alternative forced-choice preferential-looking staircase protocol. Contrast thresholds at three spatial frequencies (0.38, 1.5, and 6 cyc/deg) were measured at each of two temporal frequencies (2- and 8-Hz sinusoidal counterphase modulation) using D6 grating patches. RESULTS: Grating acuity deficits in the immediate posttreatment period were similar in patients with a history of unilateral cataract (n=10) and those with a history of bilateral cataracts (n=6) when treatment was provided during the first 8 weeks of life. With later treatment, patients with a history of unilateral cataract (n=7) had significantly larger grating acuity deficits than patients with a history of bilateral cataracts (n=6). Children with a history of dense congenital unilateral cataract had similar deficits in contrast sensitivity to children with a history of bilateral cataracts when treatment was initiated during the first 8 weeks of life. When treatment was initiated later (i.e., at 12-30 weeks), patients with a history of unilateral cataract showed greater deficits in contrast sensitivity and a dependence of the amount of spatial contrast sensitivity deficit on temporal frequency than did patients with a history of bilateral cataracts. CONCLUSIONS: These findings support the hypothesis that only visual deprivation is active as an amblyogenic factor during the first weeks of life, but when unilateral deprivation is prolonged to 12 to 30 weeks, unequal competition also plays a role in amblyogenesis.

Amblyopia↗
PubMed2002

Infantile cataract in the collaborative perinatal project: prevalence and risk factors.

OBJECTIVES: To estimate the prevalence of 4 categories of infantile cataract in subjects surviving the neonatal period in a US cohort, and to investigate risk factors for isolated infantile cataract. DESIGN: Prospective study of 55 908 pregnancies enrolled in the Collaborative Perinatal Project from 1959 to 1965 at 12 university medical centers. METHODS: We gathered data on demographic, lifestyle, and prenatal and perinatal obstetrical and postnatal factors using a standardized protocol. Pediatricians and neurologists examined infants at birth, 4 months, 1 year, and 7 years. We used exact logistic regression methods to compare putative risk factors in infants with isolated cataract with those in infants with no history of cataract. OUTCOME MEASURES: Infantile cataract as diagnosed using a standardized dilated ophthalmic examination. RESULTS: Infantile cataract occurred in 13.6 per 10 000 infants (95% confidence interval [CI], 10.7-17.1). Isolated infantile cataract occurred 3.8 times as often among infants born at weights at or below 2500 g than among those born at or above 2500 g (95% CI, 1.5-8.6; P<.001), after controlling for a set of covariates; we observed similar results for bilateral isolated cataract (odds ratio = 4.4; 95% CI, 1.2-13.9). No risk factor identified in bivariate analyses was independently associated with the odds of developing isolated unilateral infantile cataract. CONCLUSIONS: Infantile cataract is a rare disorder occurring during childhood. Prevalence estimates reported here are within the limits of those from large-cohort studies in economically developed nations. Infants born at weights at or below 2500 g have a 3- to 4-fold increased odds of developing infantile cataract.

Adult↗
PubMed1989

Ultraviolet light exposure and risk of posterior subcapsular cataracts.

Posterior subcapsular (PSC) cataracts are a visually disabling form of cataract and account for 40% of surgical cases. Although PSC opacities may occur following intraocular inflammation, trauma, or use of steroids, the cause is often unknown. A case-control study was undertaken to investigate the role of exposure to ultraviolet light in the B range (UV-B) and other potential risk factors for the development of PSC cataracts. Surgical PSC cataract cases from a large rural ophthalmic practice on the lower eastern shore of Maryland were matched with phakic controls without PSC cataract changes from the same geographic area by age, sex, and referral pattern. All patients with PSC opacities who underwent cataract surgery in a 12-month period were chosen. One hundred sixty-eight cases and 168 controls were interviewed regarding sunlight exposure, drug use, occupational history, history of diabetes, hypertension, and other diseases. Matched-pairs analyses indicated that a history of relatively high exposure to UV-B was associated with increased risk of PSC cataracts. The association of PSC cataracts with steroid use and diabetes was reconfirmed. Subjects with blue eyes and less than high school education were also at increased risk for PSC cataracts. Smoking and hypertension were not found to be PSC cataract risk factors. These data suggest that UV-B exposure may be an important risk factor for PSC cataracts.

Adult↗
PubMed1995

Body mass index. An independent predictor of cataract.

OBJECTIVE: To examine whether body mass index is an independent predictor of cataract. (Body mass index is a standardized measure defined as weight in kilograms divided by the square of the height in meters.) DESIGN: Prospective cohort study, with 5 years of follow-up. PARTICIPANTS: A total of 17,764 US male physicians participating in the Physicians' Health Study, aged 40 to 84 years, who were free of cataract, myocardial infarction, stroke, and cancer at baseline and reported complete information about body mass index and other cataract risk factors. MAIN OUTCOME MEASURE: Incident cataract, defined as a self-report, confirmed by medical record review, first diagnosed after randomization, age-related in origin, and responsible for a decrease in best corrected visual acuity to 20/30 or worse. RESULTS: Incident cataract occurred during follow-up in 370 participants. In proportional hazards models that adjusted for potential confounding variables, body mass index had a strong, graded relationship with risk of cataract. Relative to those with body mass index less than 22, relative risks (95% confidence intervals) associated with body mass index of 22 to less than 25, 25 to less than 27.8, and 27.8 or more were 1.54 (1.04 to 2.27), 1.46 (0.98 to 2.20), and 2.10 (1.35 to 3.25), respectively. Relative to any given level of body mass index, a 2-unit higher level predicted a 12% increase in risk of cataract (95% confidence interval, 5% to 19%). Higher body mass index was especially strongly related to risk of posterior subcapsular and nuclear sclerotic cataracts and was also significantly related to risk of cataract extraction. CONCLUSIONS: In a prospective cohort study of apparently healthy men, higher body mass index, a potentially modifiable risk factor, was a determinant of cataract. The leanest men had the lowest rates, consistent with experimental evidence that restriction of energy intake slows development of cataract. Although precise mechanisms are unclear, the effect of body mass index on cataractogenesis is apparently independent of other risk factors, including age, smoking, and diagnosed diabetes.

Adult↗
PubMed1993

Structural characterization of lipid membranes from clear and cataractous human lenses.

Lipid composition related structural changes in human cataractous lenses was explored by characterizing the hydrophobic hydrocarbon chains in lipid membranes corresponding to twelve Indian cataractous lenses and eight American clear lenses of similar age. The nuclear-lipid phase transitions corresponding to the clear lenses exhibited significantly higher average transition temperatures (nucleus 33 degrees C, cortex 26.3 degrees C) and cooperativities, 38.1, as compared to the value of 24.1 for the cortical-lipid phase transitions. At 36 degrees C, the phase transitions corresponding to cortical and nuclear lipids indicate a similar degree of disorder, 63%, in the hydrocarbon chains, i.e., similar relative amounts of gauche and trans rotomers. The twelve cataractous lenses investigated all had nuclear opacities, four were brunescent and four had cortical opacities. No significant differences were observed in the phase transition parameters (temperature, cooperativity, magnitude, enthalpy) evaluated for the nuclear-lipid membranes corresponding to the different types of cataracts. Furthermore, for the cataractous membranes, the phase transition parameters obtained for the nuclear lipids were comparable to those evaluated for the cortical lipid membranes. However, the cortical lipids exhibited the highest order in membranes from nuclear cataracts without cortical opacity. The cortical lipids from clear, non-cataractous lenses had the lowest level of order. At 36 degrees C, the degree of order in the cortical lipid from clear lenses was comparable to that from nuclear cataractous lenses without cortical opacity. The transition temperature, and cooperativity were significantly higher for cortical lipids from cataractous lenses as compared to those from clear lenses. At 36 degrees C, the degree of order in the cortical lipid membranes was lower for all cataract types vs. clear lens fractions. Our results suggest the possibility that lipid-lipid interactions could be different in cataractous lens membranes. Lipid compositional and chemical differences must account for these altered lipid interactions. These studies will provide a basis for studying lipid-protein interactions and structure-function relationships in the lens membrane.

Adult↗
PubMed2000

Normal mouse and rat strains as models for age-related cataract and the effect of caloric restriction on its development.

The purpose of this study was to determine: (1) which of the commonly used strains of laboratory rats and mice provide good models for human age-related cataract, and (2) whether long term caloric restriction, a regimen that prolongs both median and maximum life span in rodents, would also delay the time of appearance of this age-related pathology. Three strains of mice and two rat strains commonly used in laboratory work and maintained on either ad libitum (AL) or calorically restricted (CR) diets in the National Institutes of Aging and Diet Restriction colony were examined by slit lamp for age-related cataracts at four or more time points during their life spans. These strains were Brown Norway and Fischer 344 rats, and C57BL/6, (C57BL6 x DBA/2)F1 and (C57BL/6 x C3H)F1 mice. None of these strains develop congenital cataracts. Various stages of cataract were found in the great majority of these animals in old age. In both rat strains and one mouse strain the cataracts occurred after mid-life, were most advanced late in life, and were similar in locations and appearance to those in humans. In the two mouse strains in which some cataracts appeared as early as 10-14 months of age, previously identified genetic defects affecting the eye were probably involved in the early appearances. CR extended life spain in all five rat and mouse strains and also delayed both the time of first appearances and the subsequent increase in cataract severity over time in the four dark-eyed strains. CR did not delay cataract formation in the single albino rat strain studied. In summation: (1) commonly used strains of laboratory rats and mice that are free of congenital or early appearing cataracts due to genetic defects would appear to serve as appropriate models for human age-related cataract, (2) caloric restriction (CR) provides a protective effect, delaying development of cataracts in the dark-eyed mouse and rat strains, while also extending their life spans, (3) CR did not delay the development of lens damage in the nonpigmented eye of the single albino strain studied, although it extended life span.

Aging↗
PubMed2003

Nerve growth factor (NGF) and lenses: effects of NGF in an in vitro rat model of cataract.

BACKGROUND: The aims of this study are to investigate the presence and production of nerve growth factor (NGF) in the rat lens in basal conditions and to evaluate, in vitro, the role of NGF in a model of xylose-induced cataract. METHODS: Rat lenses were dissected and the expression of NGF, NGF mRNA and high-affinity NGF-receptor (TrkA) was evaluated by immunohistochemistry, immunoenzymatic assay (ELISA) and in-situ hybridization (ISH) techniques. To investigate the role of NGF in cataract formation we used an in vitro model of sugar-induced cataract by culturing rat lenses for 48 h in Eagle's minimum essential medium (MEM) supplemented with xylose. To evaluate the potential protective effect of NGF on xylose-induced cataract formation, exogenous NGF at different concentrations or antibodies neutralizing endogenous NGF (NGF-Ab) or aspecific antibodies were added to xylose-cultured lenses, and the following cataract-related parameters were evaluated and compared to xylose-treated lenses. Cataract formation was evaluated using three different parameters: staging of the cataract by lens photography, quantification of lens transparency in terms of gray level medium (GLM) and evaluation of the hydration percentage (H%) of the lens. To investigate the role of endogenous NGF in cataract onset, NGF levels were evaluated and compared in lenses cultured in xylose supplemented medium versus lenses cultured in control culture medium. RESULTS: The epithelium from fresh rat lenses expresses NGF-receptor, NGF protein and NGF-mRNA. NGF levels in fresh lens were 54.0 +/- 24.5 pg/g as quantified by ELISA. Xylose-cultured lenses develop cataract changes, including a decrease of GLM and an increase in hydration percentage, associated with a decrease in NGF levels when compared to lenses cultured in the control culture medium. The addition of NGF to xylose-cultured lenses reduces cataract formation, increasing GLM and decreasing the hydration percentage as compared to xylose-treated lenses. On the other hand, the addition of NGF-Ab induces an increase in cataract formation and lens hydration. CONCLUSIONS: This study demonstrates that rat lens epithelium expresses and synthesizes NGF. Moreover, immunohistochemistry shows that lens epithelial cells also express the NGF receptor. Although the functional significance of TrkA on lens epithelium is at present not clear, the expression of NGF and its high-affinity receptor on the same cells together with our experimental results suggest that NGF is involved in supporting trophism and/or the function of the lens epithelium.

Animals↗
PubMed2005

Endophthalmitis following cataract surgery in southwest Finland from 1987 to 2000.

PURPOSE: To investigate the incidence, causes, prevention, treatment and outcome of postoperative endophthalmitis (POE) following cataract surgery in southwest Finland from 1987 to 2000. METHODS: We reviewed the medical records of all patients with POE following cataract surgery treated in the hospital district of Southwest Finland from 1 January 1987 to 31 December 2000. Population-based annual incidence rates of cataract extractions and POE were calculated using the corrected population statistics of the hospital district. RESULTS: There were 29,350 cataract procedures during the 14-year period. POE developed in 47 patients. The annual incidence of cataract operations increased more than fivefold from 1987 (155 per 100,000 population) to the maximum in 1999 (930 per 100,000 population), whereas the annual incidence of postcataract endophthalmitis decreased from the maximum of 11.1 per 1,000 cataract extractions (1.91 per 100,000 population) in 1988 to the minimum of 0-0.6 per 1,000 cataract extractions in 1999 and 2000. POE occurred statistically significantly more frequently after extracapsular cataract extraction (ECCE) than after phacoemulsification (Phaco) (P=0.0006). Gram-positive bacteria were the most frequent cause of acute POE and Propionibacterium acnes was the most frequent reason for delayed-onset POE. The complications of POE after cataract surgery included visual loss to below 0.05 (25.5% of affected eyes), opacification of the cornea (21.3%), secondary cataract (40.4%), increase in intraocular pressure (29.8%), vitreous clouding (63.8%), and retinal detachment (6.4%). Nearly one half of the eyes achieved final visual acuity of 0.5 or better. CONCLUSIONS: During the 14-year study period there was a shift from ECCE to Phaco, a fivefold increase in cataract extractions, and a decrease in the annual incidence of POE from 5.5-11.1 to 0-0.6 per 1,000 operations. Phaco was associated with a lower risk of POE than ECCE.

Adult↗
PubMed2002

Wavefront analysis in eyes with nuclear or cortical cataract.

PURPOSE: To compare the higher-order aberrations of the oculus (whole eye) and cornea in eyes with mild cortical or nuclear cataract and to estimate the effect of ocular higher-order aberrations on the loss of contrast sensitivity using wavefront analysis. DESIGN: Observational case series. METHODS: Six eyes of four patients with mild nuclear cataract, 18 eyes of 14 patients with mild cortical cataract, and nine eyes of nine normal patients were examined. Wavefront aberrations of the oculus and cornea for central 6 mm diameter were measured using the Hartmann-Shack (HS) aberrometer. Higher-order aberrations were calculated with Zernike polynomials up to sixth order. The relationship between average lens density (ALD) measured by the Scheimpflug camera and the ocular total higher-order aberration (OTHA) was investigated. The relationship between contrast sensitivity (CS) and the OTHA or ALD was also examined. RESULTS: The OTHA was significantly larger in cataracts compared with normal subjects, while corneal total higher-order aberration did not differ between cataracts and normal subjects. The polarity of spherical aberration was negative in all eyes with nuclear cataract while positive in all eyes with cortical cataract. The correlation between ALD and OTHA was not significant in eyes with cataracts. The CS highly correlated with OTHA while it moderately correlated with ALD. CONCLUSIONS: The HS aberrometer is useful to objectively evaluate the deterioration of images in eyes with mild cataract and it revealed that the polarity of spherical aberration was different between nuclear and cortical cataract. It was also suggested that in mild nuclear or cortical cataract, not only light scattering, but also optical aberration of the lens contributes to the loss of contrast sensitivity.

Adult↗
PubMed2003

Incidence and management of cataract after retinal detachment repair with silicone oil in immune compromised patients with cytomegalovirus retinitis.

PURPOSE: To determine the incidence of and risk factors for cataract and to describe the visual outcomes of cataract surgery in eyes with cytomegalovirus-related retinal detachments repaired with silicone oil. STUDY DESIGN: Retrospective cohort study. METHODS: A prospectively generated database of all patients with cytomegalovirus retinitis examined at a single tertiary care institution was used to identify all cases of retinal detachment between October 1983 and August 1997. Data on retinal detachment repair, development of cataract, and outcomes of cataract surgery were obtained retrospectively. RESULTS: Among 904 eyes of 587 immune-compromised patients diagnosed with cytomegalovirus retinitis, 198 eyes of 155 patients developed retinal detachment. Among these, 106 eyes of 90 patients underwent retinal detachment repair with silicone oil. The Kaplan-Meier estimated median time to cataract was 1.8 months after surgery with silicone oil. The adjusted relative risk of cataract in eyes that underwent retinal detachment repair with silicone oil compared with eyes that did not was 6.74 (P <.0001). Eight of the eyes that developed cataract underwent uncomplicated cataract surgery by phacoemulsification and posterior chamber intraocular lens implantation. Among these, six eyes experienced >or=2 lines of improvement in visual acuity. All developed posterior capsule opacification a median of 7 days after cataract surgery. Four of five eyes that that underwent neodymium:yttrium-aluminum-garnet laser capsulotomy experienced >or=2 lines improvement in visual acuity. CONCLUSIONS: There is a high incidence of cataract after surgery with silicone oil tamponade for cytomegalovirus-related retinal detachment. Posterior capsule opacification occurs rapidly after cataract surgery in these patients.

AIDS-Related Opportunistic Infections↗
PubMed1998

Diabetes, cardiovascular disease, selected cardiovascular disease risk factors, and the 5-year incidence of age-related cataract and progression of lens opacities: the Beaver Dam Eye Study.

PURPOSE: To describe the relationships of diabetes mellitus, cardiovascular disease, and selected cardiovascular disease risk factors to cumulative incidence of age-related cataract and to progression of lens opacities over a 5-year interval. METHODS: A follow-up examination of the Beaver Dam Eye Study cohort was performed 5 years after the baseline evaluation. Ages at the census prior to baseline ranged from 43 to 84 years of age. Protocols for examination, lens photography, and grading were the same for both examinations. RESULTS: Age at baseline was the most significant characteristic associated with incidence of nuclear, cortical, and posterior subcapsular cataract in those without diabetes (P < .001) for all cataracts. The positive association of age with cataract was found for nuclear and cortical cataract in the worse eye (P < or = .04) but not posterior subcapsular cataract in those with diabetes. Progression of nuclear sclerosis was common, occurring in about 70% of subjects when considering either eye. Incident cortical and posterior subcapsular cataracts (P < or = .001 for worse eye for each lesion) and progression of cortical and posterior subcapsular opacities were more common in those with diabetes (P < or = .001 for either eye for each lesion). Increased glycated hemoglobin level was associated with increased risk of nuclear and cortical cataracts in those with diabetes. Relationships of risk factors to posterior subcapsular cataracts, especially among those with diabetes, were often in the expected direction but lacked significance possibly due to small samples. CONCLUSIONS: Diabetes mellitus is associated with incidence over 5 years of cortical and posterior subcapsular cataract and with progression of more minor cortical and posterior subcapsular lens opacities. These changes may be related to level of glycemia. Cardiovascular disease and its risk factors have little effect on incidence of any age-related cataract.

Adult↗
PubMed2003

Epidemiologic study of age-related cataracts among an elderly Chinese population in Shih-Pai, Taiwan.

PURPOSE: The purpose of this study was to determine the prevalence and risk factors for age-related cataracts in a metropolitan elderly Chinese population in Shihpai, Taipei, Taiwan. DESIGN: Population-based cross-sectional study. PARTICIPANTS: A total of 2045 subjects at least 65 years of age were invited to participate, and 1361 (66.6%) participated in the survey. METHODS: An eye examination, including lens opacity grading, was conducted by ophthalmologists using the Lens Opacity Classification System III (LOCS III). A structured questionnaire was used for data collection. Interviewers also collected information on subjects' blood pressure, lifestyle (cigarette smoking and alcohol intake), medical history, and waist and hip circumferences. MAIN OUTCOME MEASURES: Subjects were defined as having age-related cataracts if there was any type of lens opacity with an LOCS III grade of more than 2 in one or both eyes. When both eyes of an individual had age-related cataracts, the more affected eye was used for analysis. RESULTS: Among the 1361 participants, 806 were diagnosed with age-related cataracts. The prevalence was 59.2% (95% confidence interval, 56.6%-61.8%). Women had a higher prevalence of cataracts than men (64.0% vs. 56.1%, P = 0.004). The prevalence of age-related cataracts increased with age (P = 0.001). Nuclear opacity was the most prevalent type (38.9%), followed by cortical opacity (21.9%) and posterior subcapsular opacity (9.2%). On the basis of the final logistic regression model, after controlling for all other covariates, increased age and female gender were factors that were associated with an increased risk for all types of cataracts. Besides age and gender, the most significant risk factor for nuclear cataracts was current cigarette smoking; the significant predictors for cortical cataracts were higher systolic blood pressure, a history of cigarette smoking in the past, and history of diabetes; the significant predictor for posterior subcapsular cataracts was higher systolic blood pressure. CONCLUSIONS: The increasing prevalence of age-related cataracts with age highlights the need to seek appropriate medical services and for preventative interventions. Elderly people often ignore the importance of seeking vision services and care to prevent blindness or visual impairment. These findings suggest that the elderly need to be educated regarding the importance of eye care by physicians and hygiene authorities in Taiwan.

Age Distribution↗
PubMed1997

Cataract after vitrectomy in young patients.

OBJECTIVE: The purpose of the study was to evaluate the occurrence of cataract in young patients after pars plana vitrectomy. DESIGN: The authors reviewed the medical records for previtrectomy and postvitrectomy lens changes in patients younger than 30 years of age at the Kellogg Eye Center, University of Michigan. PARTICIPANTS: Forty-nine patients (50 eyes) younger than 30 years of age (mean age, 23.5 years; range, 5 months-30 years) underwent phakic vitrectomy over a 12-year period. MAIN OUTCOME MEASURES: Cataracts were categorized as posterior subcapsular, nuclear sclerotic, or cortical. Cataracts also were graded as mild (1+), moderate (2+), or severe (3+). RESULTS: In this series of young patients, vitrectomy was performed for a wide range of ocular conditions, including trauma and complicated retinal detachment. Postvitrectomy cataract developed in 29 patients (60%). Eighteen patients (36%) had visually significant cataract on long-term follow-up (mean follow-up, 29.7 months; range, 6 months-13 years). The most common cataract was posterior subcapsular (57%), followed by nuclear sclerosis (23%), a combination of both (17%), and cortical cataract (3%). Patients with gas-filled eyes had a significantly higher rate of cataract formation than patients with fluid-filled eyes (P < 0.05). CONCLUSIONS: Postvitrectomy cataracts were more common in the authors' series compared with those of previous reports on young patients. Cataracts were most often posterior subcapsular and were significantly associated with the use of intraocular gas. The occurrence of postvitrectomy cataract appears to be higher in patients undergoing vitrectomy for complex ocular conditions, regardless of age.

Adolescent↗
PubMed1999

Schizophrenia, psychotropic medication, and cataract.

OBJECTIVE: To compare the distribution of cataract types between psychiatric patients diagnosed with schizophrenia and the general population not exposed to psychotropic medication, and to compare cataract prevalence between users and nonusers of various psychotropic medications in the general community. DESIGN: Case-control. PARTICIPANTS: A total of 151 (93%) eligible patients from a community mental health service and 3271 (83%) eligible residents from the Melbourne Visual Impairment Project (VIP) were examined. MAIN OUTCOME MEASURES: All patients 40 years of age and older from a community mental health service and residents of nine randomly selected areas of Melbourne were eligible. Best-corrected distance visual acuity was determined using a 4-m logarithm of the minimum angle of resolution (LogMAR) chart. The presence of cataract was determined by photographs or slit-lamp examination using direct and indirect retroillumination. Anterior, cortical, nuclear, and posterior subcapsular cataracts were measured. Participants from the Melbourne VIP were classified as to whether they had taken benzodiazepams, phenothiazines, thioxanthenes, butyrophenols, tricyclic antidepressants, or monoamine oxidase inhibitors for at least 12 months during their lifetime. RESULTS: The distribution of cataract type varied between persons with and without schizophrenia. Anterior subcapsular (ASC) cataract was significantly more prevalent (26%) in participants with schizophrenia from the community mental health service than Melbourne VIP participants (0.2%) not exposed to psychotropic medication (chi-square, 1 degree of freedom = 605.5, P = 0.001). This remained significant after controlling for age (odds ratios = 250, 95% confidence interval = 83.3, 1000). The distribution of the age-related cataract was similar across all groups of psychotropic medication users with the exception of the phenothiazine users. They had less of all types of the age-related cataracts, despite being slightly older than the control group (mean age, 60.0 vs. 58.4, t test = 0.85, P = 0.40). However, only cortical cataract in the phenothiazine group was statistically lower (chi-square, 1 degree of freedom = 3.96, P = 0.047). CONCLUSION: This study has identified the need to investigate whether other newer agents, especially high-potency medications, cause ASC opacities if a certain threshold of exposure to psychotropic medications must be attained to develop cataract, or if schizophrenia itself is associated with cataract formation.

Adult↗
PubMed2002

Dose-effect relationship for cataract induction after single-dose total body irradiation and bone marrow transplantation for acute leukemia.

PURPOSE: To determine a dose-effect relationship for cataract induction, the tissue-specific parameter, alpha/beta, and the rate of repair of sublethal damage, mu value, in the linear-quadratic formula have to be known. To obtain these parameters for the human eye lens, a large series of patients treated with different doses and dose rates is required. The data of patients with acute leukemia treated with single-dose total body irradiation (STBI) and bone marrow transplantation (BMT) collected by the European Group for Blood and Marrow Transplantation were analyzed. METHODS AND MATERIALS: The data of 495 patients who underwent BMT for acute leukemia, who had STBI as part of their conditioning regimen, were analyzed using the linear-quadratic concept. The end point was the incidence of cataract formation after BMT. Of the analyzed patients, 175 were registered as having cataracts. Biologic effective doses (BEDs) for different sets of values for alpha/beta and mu were calculated for each patient. With Cox regression analysis, using the overall chi-square test as the parameter evaluating the goodness of fit, alpha/beta and mu values were found. Risk factors for cataract induction were the BED of the applied TBI regimen, allogeneic BMT, steroid therapy for >14 weeks, and heparin administration. To avoid the influence of steroid therapy and heparin on cataract induction, patients who received steroid or heparin treatment were excluded, leaving only the BED as a risk factor. Next, the most likely set of alpha/beta and mu values was obtained. With this set, the cataract-free survival rates were calculated for specific BED intervals, according to the Kaplan-Meier method. From these calculations, cataract incidences were obtained as function of the BED at 120 months after STBI. RESULTS: The use of BED instead of the TBI dose enabled the incidence of cataract formation to be predicted in a reasonably consistent way. With Cox regression analysis for all STBI data, a maximal chi-square value was obtained for alpha/beta = 1.75 Gy and mu = 0.75 h(-1). When Cox regression analysis was applied for patients who had no steroid treatment after BMT, a maximal chi-square value was obtained for alpha/beta = 1 Gy and mu = 0.6 h(-1). Cox regression analysis was repeated using the data of patients who had not received posttransplant steroid treatment and also no heparin administration; we found alpha/beta = 0.75 Gy and mu= 0.65 h(-1). An increased cataract incidence was observed after steroid treatment of >14 weeks and heparin administration. CONCLUSION: The alpha/beta value of 0.75 Gy and mu value of 0.65 h(-1) found for the eye lens are characteristic for late-responding tissues. The incidence of cataract formation can now be quantified, taking into account the values calculated for alpha/beta and mu, TBI dose, and dose rate. Also, the reduction in cataract incidence as a result of lens dose reduction by eye shielding can be estimated.

Acute Disease↗
PubMed1999

Degeneration and transdifferentiation of human lens epithelial cells in nuclear and anterior polar cataracts.

PURPOSE: To study the possible mechanisms of cataractogenesis by evaluating the characteristics of cataractous lens epithelial cells (LECs) in different types of human cataract. SETTING: Kangnam St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea. METHODS: Lens epithelial cells attached to the anterior capsules in eyes with nuclear or anterior subcapsular were analyzed for morphological characteristics by electron microscopy and for cellular characteristics by immunohistochemistry. RESULTS: Human LECs beneath the anterior capsule were degenerated in nuclear cataracts and were transdifferentiated in anterior polar cataracts. In senile nuclear cataractous lenses, LECs beneath the anterior capsule showed degenerative changes in morphology. In nuclear cataracts, LECs were immunohistochemically positive for cytokeratin and vimentin, while those in anterior polar cataracts were positive for vimentin only. The LECs of anterior subcapsular cataracts were transdifferentiated into spindle-shaped fibroblast-like cells without cellular junctions and embedded within a fibrillar meshwork mass. The extracellular matrixes in the anterior capsule of anterior subcapsular cataracts were immunohistochemically positive for fibronectin, laminin, collagen type I, and collagen type IV. CONCLUSIONS: Lens epithelial cells in different types of cataracts have distinct cellular characteristics and may possess a bipotential nature with the ability to transdifferentiate into mesenchymal cells. This may be an underlying mechanism for the development of cataract and capsule opacification.

Adult↗