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PubMed2004

Modeling utility of second-eye cataract surgery.

OBJECTIVES: To study the impact on public health in terms of utility of various proportions of first-eye and second-eye cataract surgery. METHODS: A model was used to study the impact on a population of a fixed cataract surgical rate (9,250 operations/1,000,000 people) with varying proportions of first-eye and second-eye cataract operations. The study population was the County of Blekinge with a known incidence of previous cataract surgery. The prevalence of cataract, the estimated need for cataract surgery, and the utility values were taken from the literature. The population was grouped by disability stage of cataract and previous cataract surgery in accordance with prevalence studies and data from a large national database on cataract surgery and patients' self-assessed visual function. The mortality rate was taken from real data for the study population. RESULTS: Given a fixed cataract surgical rate over a period of five years, a high percentage of second-eye cataract surgery (42 percent) resulted in a mean utility of 0.82239 in the population forty years of age and older and the corresponding number for a low percentage of second-eye cataract surgery (25 percent) was 0.82253. A high percentage of second-eye surgeries resulted in 421 more individuals who were well compared with a low percentage of second-eye surgeries. On the other hand, a low percentage of second-eye surgeries resulted in 152 fewer individuals with disability and 118 fewer individuals with dependence compared with a high percentage of second-eye surgeries. CONCLUSIONS: A high frequency of first-eye cataract surgeries instead of second-eye surgeries affects more individuals and means an optimized improvement of utility in a population. This should be recommended if the cataract surgical rate is very insufficient. If the cataract surgical rate is high, more second-eye surgeries should be performed to optimize quality of life to as many as possible.

Adult↗
PubMed2004

Incidence and cumulative risk of childhood cataract in a cohort of 2.6 million Danish children.

PURPOSE: To determine the incidence and cumulative risk of childhood cataract in Denmark during 1980 to 2000. METHODS: A cohort of 2,616,439 Danish children born between 1962 and 2000 was followed from 1980 or from the day of birth, whichever occurred later, until their 18th birthday, death, emigration, or diagnosis of cataract, whichever occurred first. Cases were ascertained from the Danish National Register of Patients (NRP) and validated by reviewing the medical records. They were divided into four groups: congenital/infantile (CI) cataract, traumatic cataract, complicated cataract, and "other" types of cataract. RESULTS: After diagnostic validation, 1311 children with cataract (59% with CI cataract) were included in the study. During 1995 to 2000 the overall cumulative risk of childhood cataract was 108.4 per 100,000 children. There was no significant difference in incidence between girls and boys or over time (1980 to 2000) for CI, complicated, and "other" types of cataract. In contrast, the incidence of traumatic cataract was significantly higher among boys. It remained increased during the entire study period despite a 23% decrease per 5 years among boys. Sixty-six percent of the children diagnosed with CI cataract below 2 years of age underwent surgery within 1 year. CONCLUSIONS: The stable incidence during a 20-year period of CI cataract and complicated cataract indicates that risk factors for these conditions have remained unchanged, whereas the marked drop of traumatic cataract among boys most likely reflects changed behavior and an increased focus on preventive measures.

Adolescent↗
PubMedDate not supplied

[Parameters of oxidative stress in the lens, aqueous humor and blood in patients with diabetes and senile cataracts].

INTRODUCTION: Contemporary hypothesis considers the oxidative stress as a crucial event in age-related processes in the body, as well as in the age-related cataract formation. Disturbance of balance between oxidative processes and antioxidative defenses causes the oxidative stress that can damage proteins, lipids, polysaccharides and nucleic acids. The secondary aging factors accelerate ageing processes. One of them is diabetes. It's numerous consequences that appear in the eye are well known. PURPOSE: The purpose of this paper is to analyze influence of the non-insulin-dependent diabetes (Type II) on cataract genesis mainly through action of the oxidative stress and antioxidative defense. MATERIAL AND METHODS: Here were analyzed contents of the lipid oxidation products (lipid peroxides--LP) and total sulfhydryle groups (TSH) in the lens' corticonuclear blocks and antioxidative capacity in their humour aqueous expressed as percent of induced malondyaldehyde (% iMDA) in 14 samples obtained from patients with cataract and diabetes mellitus type II (without diabetic complications; duration of diabetes was 0-17 years) and compared to 66 samples of patients with cataract without diabetes, as well as some parameters of the oxidative stress in serums (content of vitamin C, acrobat--A, dehydroascorbate--DA and their relation, vitamin E, glutathione--GSH, peroxidase--P and catalase--Cat activity, content of malondyaldehyde--MDA and % iMDA) of 27 patients with age-related cataract and diabetes mellitus type II (without complications; same duration), and compared to the other 135 age-related cataract patients. Data were analyzed by multivariant and univariant analysis of variance (multivariant t-test, MANOVA and ANOVA). Also were analyzed frequencies of the secondary serium diseases in a clinical group of 162 patients with cataract and sex and age matched 55 examined people without cataract, as a control group, by a logistic regression. RESULTS: Patients with diabetes and cataract have lower values of almost all investigated parameters of antioxidative defense in their serum and higher level of the lipid peroxidation products (multivariant: p > 0.05). Level of glutathione in their serums is significantly lower (t = 2.27; p = 0.028). Intensity of lipid peroxidation in corticonuclear lens blocks is higher in patients with diabetes, whereas their total sulfhydryle groups and % iMDA in humour aqueous shows lower antioxidant capacity in the same group, probably because of higher intensity of oxidative stress, although not significantly (T = 2.23; F = 0.95; p > 0.05; univariant: p > 0.05). Also, by investigation of frequencies of the secondary ageing diseases in patients with age-related cataract and age and sex matched control subjects, by a logistic regression was found high odds ratio for diabetes (?2 = 18.87; p = 0.0044; const = 0.379; OR = 2.506). DISCUSSION: Statistically lower level of the serum glutathione in diabetic patients is important index of higher level of oxidative stress in their organism. Values of other investigated parameters of oxidative stress and antioxidative defense point to the some process. However, serum's parameters are not quite specific to the cataract, because active homeostatic mechanisms at the level of hematocamerular barrier and lens' metabolism could maintain local environment to the some extent. Yet, importance of glutathione level and metabolism of the eye's lens is great. Similar meaning bear the other sulfhydrile groups, i.e. of the lens' proteins-crystallines. So, total sulfhydrile groups level is good mark for the lens antioxidative defense, as well as the lipid peroxides are good mark for the intensity of oxidative processes. Percent of induced MDA in humour aqueous may be considered as the rest of antioxidative defense, similar to it's meaning in serum. Intensity of the oxidative stress in local compartment in diabetic patients in this paper is higher, compared to other age-related cataract patients without diabetes. Lack of significance could be explained by mentioned characteristics of the group (i.e. diabetics without complications), compared with other authors results, whose examined patients have had proliferative diabetic retinopathy. The odds ratio value of diabetes to the age-related cataract also confirms that diabetes is a risk factor for the age-related cataract genesis. CONCLUSION: Results confirm hypothesis of the oxidative stress role in the age-related cataract genesis, especially in patients with diabetes mellitus. Parameters of their antioxidative defense are lower and those of oxidative stress are higher in serums and in the lenses and humour aqueous. They also point to the dynamics and diversity of oxidative stress and antioxidative defense in different compartments of the body, as well as their different meaning in distinct physiological and pathological conditions.

Aged↗
PubMed1999

Refractive associations with cataract: the Blue Mountains Eye Study.

PURPOSE: To assess the relationship between myopia and age-related cataract in a defined older population. METHODS: A cross-sectional study of 3654 people aged 49 to 97 years was conducted in the Blue Mountains near Sydney, Australia, from 1992 through 1994. General medical, eye, and refractive history and information about confounders were collected by questionnaire. Participants had a detailed determination of refraction, and the spherical equivalent refraction of each eye was calculated. The Wisconsin Cataract Grading System was used in masked grading of slit lamp and retroillumination lens photographs, to assess presence and severity of nuclear, cortical, and posterior subcapsular (PSC) cataract. Data from both eyes were analyzed by the generalized estimating equation method, adjusting for cataract risk factors. RESULTS: Included in the analysis were 7308 eyes. A history of wearing distance glasses, excluding eyes with current hyperopic refraction, was used as a proxy for myopia. Subjects who had worn distance glasses were more likely to have nuclear cataract (odds ratio [OR] 1.3; confidence interval [CI] 1.0-2.1). After stratification by age at first wearing distance glasses, this relationship remained only for people who first wore distance glasses after age 40 years (OR 1.3; CI 1.0-1.8), which suggested a myopic refractive shift from developing nuclear opacity and was supported by the weak association found between current myopic refraction and nuclear cataract (OR 1.3; CI 1.0-1.6). Eyes with onset of myopia before age 20 years had the greatest PSC cataract risk (OR 3.9; CI 2.0-7.9). This was supported by the finding of an association between current myopic refraction and PSC cataract (OR 2.5; CI 1.6-4.1). PSC cataract was inversely associated with hyperopia (OR 0.6; CI 0.4-0.9). Refraction-related increasing odds were found between PSC cataract and myopia: low myopia (OR 2.1; CI 1.4-3.5), moderate myopia (OR 3.1; CI 1.6-5.7), and high myopia (OR 5.5; CI 2.8-10.9). High myopia was associated with PSC, cortical, and late nuclear cataract. CONCLUSIONS: Early-onset myopia (before age 20 years) may be a strong and independent risk factor for PSC cataract. The findings suggest the possibility of a dose response between levels of myopia and PSC cataract. Nuclear cataract was associated with presumed acquired myopia, whereas high myopia was associated with all three types of cataract.

Age Factors↗
PubMed1999

Pyramidal anterior polar cataracts.

OBJECTIVE: To document clinical features and subsequent management of pyramidal anterior polar cataracts in children. DESIGN: Retrospective, noncomparative case series and clinicopathologic correlation. PARTICIPANTS: Fifteen patients who presented to the pediatric ophthalmology clinic. INTERVENTION: All patients underwent measurement of visual acuity, assessment of ocular motility, examination of the anterior and posterior segments, and cycloplegic refraction. Amblyopia treatment was instituted when appropriate. When visual impairment occurred from cataract progression or amblyopia or both, cataract removal with or without lens implantation was performed. After surgery, correction of refractive error and treatment of amblyopia were instituted. Several pyramidal opacities were retrieved during cataract extraction and examined by light and electron microscopy. MAIN OUTCOME MEASURES: Visual acuity at initial presentation, size of lens opacity before surgery, amblyopia status, most recent visual acuity after cataract extraction, and histologic examination of lens opacity. RESULTS: Nine children had bilateral and six had unilateral pyramidal cataracts (24 eyes). There was no discernible inheritance pattern. Patients were followed for 27 months on average. Twenty of 24 eyes developed cortical opacification that extended significantly beyond the base of the pyramidal lesion. Nineteen eyes required cataract surgery: 10 eyes underwent lensectomy with anterior vitrectomy and 9 had extracapsular cataract extraction, 8 of which had insertion of a posterior chamber intraocular lens. Amblyopia was present or developed in all six patients with unilateral cataract and in eight of nine patients with bilateral cataract. Visual acuity in many eyes remained poor despite amblyopia therapy. The pyramidal opacities consisted of hyperplastic lens epithelium, which exhibited a loss of polarity and was surrounded by a collagenous matrix. CONCLUSIONS: Pyramidal anterior polar cataracts are present at birth and may represent a variant of anterior polar lens opacities. They may be unilateral or, if bilateral, they may be either symmetric or asymmetric. They consist of hyperplastic lens epithelium in a collagenous matrix. Patients with pyramidal cataracts are likely to develop amblyopia. This can result from either unilateral occurrence or asymmetry of bilateral opacities and is often worsened by surrounding cortical opacification. Many patients require cataract surgery. All infants and young children with anterior polar opacities showing this configuration should be followed for cataract progression and amblyopia.

Adolescent↗
PubMed2003

Laser cataract surgery: technique and clinical results.

PURPOSE: To study the effectiveness of an erbium:YAG (Er:YAG) laser in removing nuclei of various densities. SETTING: University clinic. METHODS: This nonrandomized prospective clinical study included 147 consecutive cataractous eyes: Group 1 (n = 71) had conventional ultrasound, and Group 2 (n = 76) had surgery with the Er:YAG laser. The 2 groups were further classified by cataract density. Patients were examined 6 months postoperatively to evaluate surgical time, intraocular pressure (IOP), pachymetry, endothelial cell loss, and visual acuity. RESULTS: With ultrasound cataract surgery, there were no significant changes in IOP compared with the preoperative measurements. Laser treatment of 3+ and 4+ cataracts resulted in IOP increases of 12.6% and 18.2%, respectively, compared with 1+ and 2+ cataracts (P<.001). Slight endothelial cell losses occurred in all cases. With ultrasound, the mean decrease was 2.8%, and with laser surgery, the results were similar except for a significant decrease of 13.4% with 4+ cataracts. There was a correlation between pachymetry and surgical time when the trauma related to surgical time and hydrodynamic flow in the anterior chamber was assessed. With ultrasound, the visual acuity was similar with all types of cataract; with the laser, similar normal values were seen with 1+ and 2+ cataracts but decreased values were seen with 3+ cataracts and lower values with 4+ cataracts-0.43 compared to 0.84 best corrected visual acuity with same-density cataracts treated with ultrasound (P<.0005). Patients with 4+ cataracts treated with the laser developed more complications than those treated with ultrasound. CONCLUSIONS: The Er:YAG laser was as effective and reliable as ultrasound in removing soft and medium-density cataracts. With dense cataracts, the surgical length produced more trauma and complications during laser treatment than during ultrasound treatment.

Aged↗
PubMed2000

Immunolocalization of transforming growth factor-beta1 and tenascin in human secondary cataract.

PURPOSE: This study was carried out to investigate the distribution of transforming growth factor-beta1 (TGF-beta1) and the extracellular matrix (ECM) glycoprotein tenascin in secondary cataract and anterior subcapsular cataract. METHODS: Twenty-four pseudophakic human eyes with secondary cataract, obtained at autopsy 1 d to 10 yr (mean 2.4 yr) after cataract surgery, were studied. Additionally, a specimen from an anterior subcapsular cataract was included. Immunohistochemistry was used to localize TGF-beta1 and tenascin in secondary cataract and in anterior subcapsular cataract. RESULTS: Polyclonal antibody to TGF-beta1 immunolabelled spindle-shaped cells in the plaques of secondary cataract in all eyes. Instead, the cells present in Soemmering's ring cataract were not labelled. The ECM in the plaques of secondary cataract was immunoreactive for tenascin in all eyes. In anterior subcapsular cataract spindle-shaped cells and ECM showed similar immunoreactivity. CONCLUSION: Spindle-shaped cells that are immunolabelled with TGF-beta1 and ECM showing tenascin-like-immunoreactivity are present in secondary cataract and in anterior subcapsular cataract, thus implicating a possible role in secondary cataract.

Aged↗
PubMed2005

Relationship of cataract symptoms of preoperative patients and vision-related quality of life.

BACKGROUND: This study was conducted in an attempt to describe the status of cataract symptoms of preoperative cataract patients, as well as to determine the relationship between cataract symptom and vision-related quality of life measures. RESEARCH DESIGN: A cross-sectional study design was used. Study subjects were selected using non-probabilistic methods. The study sample consisted of 132 patients scheduled for cataract surgery in one eye. Information was obtained from study subjects by conducting face-to-face interviews. PARTICIPANTS: Study subjects were adult cataract patients at Samsung and Kunyang General Hospitals in Seoul, Korea, and Tulane University Hospital and Clinics in New Orleans, Louisiana, United States of America. MEASUREMENTS: Degree to which study subjects were "bothered" by cataract symptoms was measured by using the 5-item Cataract Symptom Scores (CSS). The number of symptoms, highest scored symptom among the five, number of symptoms extremely bothering, and the mean of cataract symptom score were created based on the CSS measure. Vision-related quality of life was assessed by using the Visual Function 14 Items (VF-14) and Global Measure of Vision (GMV) for trouble and satisfaction. RESULTS: The symptoms "blurry vision" and "worsening of vision" were most frequently reported. The symptom "colors looking different" was rarely reported among preoperative cataract patients. The degree to which study subjects were bothered by "blurry vision" and "seeing glare, halo, or rings" was highly associated with visual function, visual trouble, and visual satisfaction. Multiple regression analysis revealed that the newly developed cataract symptom-related scales, as well as total amount of degree to which study subjects were "bothered" by symptoms were highly related to vision-related quality of life measures. These relationships were persistent after controlling for major socio-demographic variables. CONCLUSIONS: The results indicate that cataract symptoms are highly associated with vision-related quality of life. The results also suggest that the number of symptoms, highest scored symptom among the five, number of symptoms extremely bothering, and the mean cataract symptom scores should be considered an important cataract symptom-related scale when analyzing quality of life, including cataract symptom.

Aged↗
PubMed2004

A nationwide Danish study of 1027 cases of congenital/infantile cataracts: etiological and clinical classifications.

OBJECTIVE: To study the distribution of congenital/infantile cataract in the entire population of Denmark according to etiological and clinical classifications. DESIGN: Population-based cohort study with retrospective chart review. PARTICIPANTS: All children (0 to 17 years old) who were born between 1959 and 2001 and registered with congenital/infantile cataract in Denmark during the period 1977 to 2001. Cases were ascertained from the mandatory Danish National Register of Patients, and all medical records were reviewed. METHODS: Etiological and clinical classifications of the cataract cases were based on information from the medical records. MAIN OUTCOME MEASURES: Classification of congenital/infantile cataract according to presumed etiology; gender; clinical appearance, including laterality and morphology; and the time trends according to etiology and laterality. RESULTS: A total of 1027 children with congenital/infantile cataract, 529 boys and 498 girls, were included, of whom 64% were bilateral. Males predominated with bilateral cataract, whereas females predominated with unilateral cases. Isolated cataract was the most frequent clinical presentation (71% of all cases), followed by an even proportion of cataract associated with additional ocular dysmorphology and cataract associated with systemic anomalies. Almost two thirds of all cases had an unknown etiology (idiopathic). Idiopathic cases showed a higher proportion of unilateral cataract and of additional ocular dysmorphology compared with cases of known etiology. The etiology was unknown in 87% of unilateral cases and in 50% of bilateral cases. The distribution by presumed etiology was stable during the study period, except for cataract caused by maternal infections, which decreased mainly due to the elimination of congenital rubella. CONCLUSIONS: With the exception of the decline of congenital rubella, the proportion of congenital/infantile cataract cases of unknown, genetic, and infectious origins has been stable since the late 1970s. The causes of 87% of unilateral cataracts and 50% of bilateral congenital/infantile cataracts remain unknown, making the prevention of the disease a continuing challenge.

Adolescent↗
PubMed2002

Reactivations of ocular toxoplasmosis after cataract extraction.

PURPOSE: To determine the risk of reactivation of ocular toxoplasmosis following cataract extraction. DESIGN: Retrospective case-control study. PARTICIPANTS: Out of 154 patients with ocular toxoplasmosis, 14 patients (15 eyes) who had undergone a cataract extraction and 45 age- and sex- matched controls without cataract were selected. INTERVENTION: A review of the medical records of 14 patients with ocular toxoplasmosis and cataract and 45 control patients with ocular toxoplasmosis but without cataract. The clinical records of the controls and patients were assessed for an identical 4-month period following the date of the cataract extraction in the index patients. MAIN OUTCOME MEASURES: Development of a new active retinal lesion within 4 months after cataract surgery in patients and age -and sex matched-controls. The presence of risk factors such as sex, congenital or postnatal acquisition of ocular toxoplasmosis, age at first clinical manifestation of ocular toxoplasmosis, total number of attacks per affected eye, type of cataract, age at the time of cataract surgery and the intervals between surgery and first clinical manifestation of ocular toxoplasmosis and between surgery and the last recurrence of ocular toxoplasmosis, as well as the use of antiparasitic medication during surgery, type and complications of surgery and optimal visual acuity before and after cataract surgery. RESULTS: Reactivations of ocular toxoplasmosis following cataract extraction occurred in 5/14 patients (5/15 eyes), which was higher than the incidence of recurrences in age -and sex-matched controls (p < 0.001). No additional risk factors for the development of recurrences of ocular toxoplasmosis after cataract surgery were found. Incidence of recurrences preceding surgery did not differ between patients and controls. CONCLUSION: We identified an increased risk of reactivation of ocular toxoplasmosis following cataract extraction which implies that prophylactic treatment with antiparasitic drugs during and after the cataract surgery might be worthwhile for patients at risk of visual loss.

Adolescent↗
PubMed1999

Cataract and age-related maculopathy: the Blue Mountains Eye Study.

PURPOSE: To assess the relationship between different types of cataract or past cataract surgery and late or early age-related maculopathy (ARM) in an older population. METHODS: A population-based survey examined 3,654 people aged >/=49 years, 82% of permanent residents of an area near Sydney, Australia. Participants had a detailed eye examination, including standardised dilated lens and stereo macular photographs. Presence of cataract and ARM was diagnosed from masked photographic grading using the Wisconsin Cataract and Age-related Maculopathy Grading Systems. Generalized Estimating Equation (GEE) and logistic regression models were used in the statistical analysis. RESULTS: Higher prevalence was found for both late and early ARM in eyes with cataract or a past history of cataract surgery. However, after adjusting for age, sex and other ARM risk factors, no consistent association was found between presence of cortical, nuclear or posterior subcapsular (PSC) cataract or past history of cataract surgery and either late or early ARM. In the GEE model, the only statistically significant association found was between PSC and late ARM. Non-significant increased odds were found for late ARM in eyes with cortical cataract. However, detailed analyses of cortical cataract location failed to show a relationship. CONCLUSIONS: The co-existence of cataract and ARM was almost entirely explained by the age-related increase in prevalence of both conditions. We found no evidence of a consistent relationship between cortical, nuclear or PSC cataract or history of past cataract surgery and either late or early ARM, after adjusting for age and other potential ARM risk factors. The possibility of a relationship between PSC and late ARM or between cortical cataract and any ARM was not excluded. Long-term follow up data from this population will be useful.

Age Factors↗
PubMedDate not supplied

Lens morphometry determined by B-mode ultrasonography of the normal and cataractous canine lens.

PURPOSE: To determine axial lens thickness, anterior chamber depth and axial globe length in canine eyes with normal lenses and in eyes with immature, mature, congenital, posterior polar and diabetic cataract. METHODS: B-mode ultrasonography was performed in 50 normal dogs and, as a prephacoemulsification screening procedure, in 100 dogs with cataract. Axial B-mode ultrasonograms were used to determine lens thickness, anterior chamber depth and globe diameter. Statistical comparisons between groups were made by analysis of variance and multivariate analysis, with a significance level of P < 0.05. RESULTS: Axial globe lengths were not statistically significantly different between groups apart from the smaller globes in younger dogs with congenital cataract. Axial lens thickness in diabetics (8.4 +/- 0.9 mm) was statistically significantly different from the lens thickness in normal eyes (6.7 +/- 1.0 mm), eyes with immature cataract (6.4 +/- 0.8 mm) and eyes with mature cataract (7.4 +/- 0.9 mm) although these groups, while varying in thickness, were not statistically significantly different from each other. Anterior chamber depth was statistically significantly reduced in eyes with diabetic cataract (2.9 +/- 0.1 mm) from that in normal eyes (3.8 +/- 0.1 mm), eyes with immature cataract (3.5 +/- 0.1 mm) and eyes with mature cataract (3.2 +/- 0.6 mm) although these groups, while varying in chamber depth, were not statistically significantly different from each other. CONCLUSIONS: Lenses with diabetic cataracts were significantly increased in axial thickness compared to lenses in other eyes, although lenses with mature cataracts showed a trend towards increased axial thickness and immature cataracts demonstrated a trend towards reduced thickness. While previous studies on cataract pathobiology have suggested a reduction in lens thickness in immature cataract through lens protein loss and an increase in thickness in mature cataracts through intumescence, this study is the first to document these changes in the canine lens.

Animals↗
PubMedDate not supplied

The effect of a topical antioxidant formulation including N-acetyl carnosine on canine cataract: a preliminary study.

OBJECTIVE: To determine the efficacy of a topical antioxidant formulation including N-acetyl carnosine in the treatment of canine cataract in a preliminary nonplacebo, controlled, unmasked study. ANIMALS STUDIED: Thirty dogs of varying breeds and ages with a spectrum of lens opacities ranging from nuclear sclerosis to total mature cataract. METHODS: Dogs were treated three times daily with topical 2% N-acetyl carnosine in a buffered vehicle containing the antioxidants glutathione, cysteine ascorbate, L-taurine and riboflavin (Ocluvet, Practivet, Phoenix, AZ, USA). Dogs were examined prior to treatment and at 2, 4 and 8 weeks during treatment, by direct and indirect ophthalmoscopy and slit-lamp biomicroscopy after pharmacologic pupil dilation. Photographic documentation of lens opacity was achieved by retroillumination photography, with three photographs taken at each examination time-point. A lens opacification index (LOI), determined by integration of the grayscale level of each pixel across the image, was evaluated by computerized image analysis of digitized images. Alteration in mean LOI was determined for each animal, having normalized the initial LOI. RESULTS: Fifty-eight eyes of 30 dogs were evaluated, 22 with mature cataract, 13 with immature cataract, 9 with cataract associated with other intraocular disease such as uveitis and 14 with nuclear sclerosis alone. One dog was unilaterally anophthalmic after previous enucleation and one had a phthytic eye after previous uveitis-induced glaucoma. Image analysis showed a reduction in mean LOI in all cataract groups (mean resolution in opacity of 2.3 +/- 0.33% for all cataracts), although this was only statistically significant in those eyes with immature cataract (mean resolution of opacity 4.5 +/- 0.33%) or nuclear sclerosis (mean decrease in opacity 5 +/- 0.37%). Reduction in lens opacity was seen in eyes with mature cataract (0.5 +/- 0.4%) and in miscellaneous cataract associated with intraocular inflammation (1.3 +/- 0.4%), but these changes were not statistically significant. Owner evaluation of visual capability, however, suggested improvement in vision in 80% of cases by the end of the study. CONCLUSIONS: This study demonstrates some marginal reduction in lens opacification in a substantial number of cases of canine cataract with the use of a topical nutritional antioxidant formulation including N-acetyl carnosine. Lens opacification was improved with treatment in eyes with immature cataract or nuclear sclerosis while in eyes with mature cataract or cataract with associated intraocular inflammatory pathology less reduction was seen.

Administration, Topical↗
PubMed2002

Lens and cataract research of the 20th century: a review of results, errors and misunderstandings.

Lens and cataract research from a clinical, biophysical, biological and mainly biochemical point of view has a long tradition. Already since the beginning of the 20th century research relating to the chemical composition and metabolism of the lens was conducted. With these analyses an attempt was made to understand the existence and maintenance of lens transparency and the mechanisms leading to lens opacities. Around the middle of the century the stationary analyses measuring the content of certain substances in the lens were more and more replaced by the search for dynamic metabolic processes responsible for lens growth, maintenance of transparency and possibly active participation in lens function (such as accommodation). Also the disturbances as a result of ageing or the formation of lens opacities have been investigated and resulted partially in the elucidation of reaction chains, leading from a trigger to the formation of a cataract. Lens biochemistry is no longer a closed book to us, but there are still many question marks. Why were we not able to solve more problems around lens and cataract? The research effort with a remarkable financial input and a great number of scientists worldwide during the second half of the century does not correspond to the results obtained. There must be something wrong with our strategy, our interpretation of the results or even both. We would like to stress some points which might be regarded as errors or misunderstandings in the lens research community, thus preventing a better outcome of the enormous investment of work and money. A great disadvantage is the missing cooperation between clinicians and epidemiologists on one hand and basic lens researchers on the other. Especially the ignorance of basic researchers regarding the clinical problems of the lens and of cataracts might be to blame for several 'errors and misunderstandings'. It is not even so long ago since the slitlamp microscope examination of animals belonged to the essential standard methods of a lens research team. Another disadvantage still is the use of the general diagnosis 'cataract' by the clinicians without further classification of the topography of the opacification, which supports the concept that all cataracts have the same trigger mechanism. But most regrettable is the fact that many clinicians have never been really interested in basic research of the lens, in cataract pathogenesis and epidemiology of risk factors or in testing the efficacy of cataract-preventing medication. Their main goal was cataract surgery. On the basis of the success of the cataract surgery at the present time clinicians have even developed the opinion that lens and cataract research is no longer necessary to overcome cataract blindness. But as we all know this refers only to highly industrialized countries; millions of cataract-blind people are still without such help and a change of this condition is not in sight. In our opinion lens and cataract research is still necessary and it will be more successful if we bear in mind the mostly unintentional errors of the 20th century but keep them out of our daily practice.

Animals↗
PubMed2005

Calpain may contribute to hereditary cataract formation in sheep.

PURPOSE: To determine the involvement of calpain in ovine cataractogenesis by measuring calcium, calpain activity, proteolysis, and the effect of calpain inhibition. METHODS: Sheep with genetic cataracts were examined for cataract severity. Calcium in normal and cataract lenses was measured. The presence of calpain was detected by casein zymography and immunoblotting. Calpain activity was assayed using BODIPY-casein as a substrate. Degradation of calpain substrates spectrin and vimentin was assessed by immunoblotting. The calpain inhibitor SJA6017 was applied to the left eye of cataract lambs, leaving the right eye as an untreated control. Both eyes were monitored by slit-lamp microscopy for cataract progression. RESULTS: Cortical cataracts were first observed in lambs at 1 to 2 months of age. Lens calcium concentration increased in the early stages of cataract formation and was >10-fold higher in mature cataract than normal lenses. Three calpain isoforms were detected in young lamb lenses. Calpain activity decreased as cataracts progressed. Both spectrin and vimentin were degraded with cataract maturity, which could indicate calpain proteolysis. Cataract lambs treated with SJA6017 eyedrops over a period of 4 months showed significantly smaller cataracts in the left treated eye over the right untreated eye. CONCLUSIONS: The presence of calpains and calcium elevation during cataract formation suggests that proteolysis may play a role in opacification in ovine lens. This hypothesis is supported by the delay in opacification with SJA6017 treatment. The results also suggested that the ovine hereditary cataract is a useful nonrodent model to test the role of calpains in cataractogenesis.

Animals↗
PubMed2006

Comparison of age-specific cataract prevalence in two population-based surveys 6 years apart.

BACKGROUND: In this study, we aimed to compare age-specific cortical, nuclear and posterior subcapsular (PSC) cataract prevalence in two surveys 6 years apart. METHODS: The Blue Mountains Eye Study examined 3654 participants (82.4% of those eligible) in cross-section I (1992-4) and 3509 participants (75.1% of survivors and 85.2% of newly eligible) in cross-section II (1997-2000, 66.5% overlap with cross-section I). Cataract was assessed from lens photographs following the Wisconsin Cataract Grading System. Cortical cataract was defined if cortical opacity comprised > or = 5% of lens area. Nuclear cataract was defined if nuclear opacity > or = Wisconsin standard 4. PSC was defined if any present. Any cataract was defined to include persons who had previous cataract surgery. Weighted kappa for inter-grader reliability was 0.82, 0.55 and 0.82 for cortical, nuclear and PSC cataract, respectively. We assessed age-specific prevalence using an interval of 5 years, so that participants within each age group were independent between the two surveys. RESULTS: Age and gender distributions were similar between the two populations. The age-specific prevalence of cortical (23.8% in 1st, 23.7% in 2nd) and PSC cataract (6.3%, 6.0%) was similar. The prevalence of nuclear cataract increased slightly from 18.7% to 23.9%. After age standardization, the similar prevalence of cortical (23.8%, 23.5%) and PSC cataract (6.3%, 5.9%), and the increased prevalence of nuclear cataract (18.7%, 24.2%) remained. CONCLUSION: In two surveys of two population-based samples with similar age and gender distributions, we found a relatively stable cortical and PSC cataract prevalence over a 6-year period. The increased prevalence of nuclear cataract deserves further study.

Age Distribution↗
PubMedDate not supplied

[Cataract blindness in people 50 years old or older in a semirural area of northern Peru].

OBJECTIVE: To determine the prevalence of blindness and of cataract blindness in persons 50 years of age or older in Piura and Tumbes, which are two departments in northern Peru, and to describe the coverage and quality of cataract surgery services in that area, and the barriers that prevent access to those services. METHODS: Systematic sampling of persons 50 years old or older was done in Piura and Tumbes between August 2002 and March 2003, with 80 clusters of 60 people each being selected. Of the 4 800 persons chosen, 4,782 of them were examined, using a survey instrument that gathered general information on each person, the results of the visual acuity test and the lens examination, and information on cataract surgery or why that surgery had not been done. Visual acuity (VA) testing was done with a Snellen optotype with the letter "E," with sizes of 20/60 and 20/200 at distances of 6 m and 3 m, respectively, with the person using the visual correction (glasses) available. When the VA was less than 20/60 in one of the eyes, vision was tested with pinhole glasses. RESULTS: The prevalence of bilateral blindness (VA < 20/400) due to cataract, adjusted by age and sex, was 2.1% (95% confidence interval (CI): 1.7% to 2.6%). Among the 193 persons with bilateral blindness due to any cause, cataract was the cause in 104 of them (53.9%). The prevalence of blindness due to cataract or other causes increased with age and was higher in women than in men. Only 25% of the persons studied who needed cataract surgery had had that done. The prevalence of bilateral VA less than 20/200 due to unoperated cataract was 6.3% (95% CI: 5.3% to 7.3%); only 12% of the persons with that level of visual deficiency had had cataract surgery. The VA of 26% of the eyes operated on for cataract was lower than 20/200. The reasons given by persons who needed cataract surgery but who had not had it included not being able to pay for the operation (28%), lack of knowledge concerning cataracts (25%), fear of the operation (23%), and fear of completely losing their sight (17%). CONCLUSIONS: Most of the cases of blindness and of serious deficiency in visual acuity in persons 50 years old or older in Piura and Tumbes are due to uncorrected refractive defects, especially cataracts. The high prevalence of bilateral blindness due to cataracts (2.1%) could be reduced with measures that facilitate access to appropriate treatment.

Aged↗
PubMed1999

[Data analysis on epidemiologic survey of cataract in China].

OBJECTIVE: To approach the prevalence of age-related cataract and its relationships with the condition of examination, diagnostic criteria and geographical environment in various areas. METHODS: According to the WHO's criteria of blindness and low vision, a statistical analysis of a national sample survey of blindness and low vision was carried out over the country. RESULTS: The number of patients with age-related cataract and visual acuity < 0.3 in both eyes calculated in the whole population was more than 5 million, the prevalence being 0.46%. The prevalence of blindness and that of low vision were 0.43% and 0.58% respectively. Among the blind, 41.06% was caused by cataract, and the low vision caused by cataract was 49.38%. Among elderly of >or= 60 years, the proportion of the blind and low vision caused by cataract was 73.13%. When the cataract standard was defined as lens opacity with visual acuity < 0.7, the prevalence of cataract was 5.99% in Beijing sample survey at the suburb area. The incidence of age-related cataract in females was significantly higher than that in males. In a survey of Beijing suburb in 1997, the prevalence of cataract among 5,084 elderly people of >or= 50 years with bilateral corrected visual acuity < 0.1 was 2.22%. In the southern part of China, the area of low latitude, especially in the plateau, such as in Guangdong Province (0.69%) and in Tibet (1.04%), the prevalence of cataract is much higher than that in northern part, high latitude areas, such as Heilongjiang Province (0.26%). A comparative study of the cataract prevalence of elderly >or= 40 years in the areas of different levels above the sea and sunshine times, it shows that the higher level above the sea and longer sunshine time the higher cataract prevalence. CONCLUSIONS: A longer sunshine time and a larger amount of ultraviolet irradiation are considered as the risk factors of cataract. Age-related cataract is the leading cause of blindness and the low vision in China.

Adolescent↗