Incidence and Progression of Lens Opacities

Effects of hormone replacement therapy on lens opacity, serum inflammatory cytokines, and antioxidant levels

PURPOSE

To evaluate the effect of hormone replacement therapy (HRT) on lens opacity as measured by Scheimpflug densitometry, serum inflammatory cytokines, and antioxidant levels.

METHODS

A total of 264 women who were at least five years beyond menopause were included. The control group of 128 patients (Group 1) did not use HRT at any time after menopause. The treatment group of 136 patients (Group 2) used HRT for5 years or more after menopause. Cortical, nuclear, and posterior subcapsular density; pentacam nucleus staging (PNS); pentacam densitometry of zone (PDZ) as measured using a Scheimpflug imaging system (Pentacam); and antioxidant and inflammatory cytokines activities in serum using multiplex bead analysiswere examined.

RESULTS

Uncorrected visual acuity (logMAR) of group1 was significantly worse than those of group 2 (p < .05). Group1 was significantly more myopic than group 2 (p < .05). Nuclear and posterior subcapsular density, PNS, and percentage of PDZ in group 1 were significantly higher than those of group 2 (p < .05). The serum IL-1m. IL-6, IL-8, and TGF-, concentrations of group 1 were significantly higher than those of group 2, and the serum catalase, superoxide dismutase 1 (SOD 1), and superoxide dismutase 2 (SOD 2) fluorescence intensities of group 1 were significantly lower than those of group 2 (p < .05).

CONCLUSIONS

Long-term use of HRT may have a protective effect against cataract formation. HRT seems to be effective in decreasing inflammation and increasing antioxidant contents in the serum of postmenopausal women.KEY MESSAGESHormone replacement therapy (HRT) decrease lens opacity in postmenopausal women as measured by Scheimpflug densitometry.HRT decrease serum inflammatory cytokines and increase antioxidant levelsin the serum of postmenopausal women.Long-term use of HRT may have a protective effect against cataract formationin postmenopausal women.

Sensitivity and latency of ionising radiation-induced cataract

When managed with appropriate radiation protection procedures, ionising radiation is of great benefit to society. Opacification of the lens, and vision impairing cataract, have recently been recognised at potential effects of relatively low dose radiation exposure, on the order of 1 Gy or below. Within the last 10 years, understanding of the effects of low dose ionising radiation on the lens has increased, particularly in terms of DNA damage and responses, and how multiple radiation or other events in the lens might contribute to the overall risk of cataract. However, gaps remain, not least in the understanding of how radiation interacts with other risk factors such as aging, as well as the relative radiosensitivity of the lens compared to tissues of the body. This paper reviews the current literature in the field of low dose radiation cataract, with a particular focus on sensitivity and latency.

Interaction between postmenopausal hormone therapy and diabetes on cataract

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Objective:

We investigated whether postmenopausal hormone therapy (HT) use interacts with diabetes, a risk factor for several age-related eye diseases.

Methods:

A cross-sectional analysis of women involved in the Canadian Longitudinal Study on Aging was performed. The random sample comprised of 15,320 community-dwelling women between ages 45 and 85 years old sampled from areas adjacent to 11 data collection centers across Canada. Information on menopausal status and HT were collected by self-report. Data on diabetes and eye disease were obtained by self-report of a physician diagnosis. Multivariable logistic regression was used.

Results:

After adjusting for demographic, lifestyle, and health variables, a multiplicative interaction was identified such that HT use for 10 years or more was associated with a much higher odds of a report of cataract in women with type 2 diabetes (odds ratio = 2.44, 95% confidence interval 1.49, 3.99) but not in long-term HT users with no diabetes (odds ratio = 1.03, 95% confidence interval 0.87, 1.21) (interaction term P value = 0.013). HT use was not associated with glaucoma or macular degeneration.

Conclusions:

Long-term HT use and type 2 diabetes interact in their relationship with cataract. This novel finding should be confirmed. If confirmed, women with type 2 diabetes should be informed that long-term HT use increases their risk of cataract.

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Video Summary:.

The role of age, sex and steroid sex hormones in radiation cataractogenesis

It is critical to identify and gain a better understanding of the factors that enhance or reduce the risk of cataractogenesis, to minimize the possibility of occurrence after deliberate (e.g., radiation therapy, interplanetary travel) or unintentional exposure to ionizing radiation. Both gender and age at the time of exposure have been established as key determinants of cataractogenesis induced by sparsely ionizing (low-LET) and densely ionizing (high-LET) radiation. However, animal data from several older studies are often conflicting and somewhat difficult to interpret, in that the experiments suffered from small group sizes, limited dose ranges or short periods of observation, and human data are sparse or statistical significance is sometimes limited. Steroid sex hormones (SSH) may underlie age and gender-based differences in the progression and prevalence of cataracts that otherwise occur spontaneously in humans and animal models, and may also underlie age and sex-related differences in radiation cataractogenesis. Here, we review data that have aided in our understanding of the role of age, sex and steroid sex hormones in radiation cataractogenesis.

The effects of postmenopausal hormone use on cataract: a meta-analysis

BACKGROUND

Cataract is the leading cause of blindness worldwide. Many observational studies assessed the relationship between postmenopausal hormone replacement therapy (HRT) and risk of cataract development, but the reported results were controversial. The aim of present meta-analysis was to evaluate the association of postmenopausal hormone replacement therapy with risk of cataract development.

METHODS

The eligible observational studies, including cross-sectional, case-control and cohort studies, were identified by searching PubMed and Embase during March of 2013. Either a fixed- or a random-effects model was used to calculate the pooled odds ratio (OR) with its 95% confidence interval (95%CI). Subgroup analysis on cataract types was performed.

RESULTS

A total of four cohort and five case-control or cross-sectional studies were finally included into this meta-analysis. Overall, a significant decreased risk of developing any type of cataract was found in ever HRT group as compared with non-HRT group among cohort studies (OR 0.83; 95%CI: 0.71,0.97) and case-control or cross-sectional studies (OR 0.74; 95%CI: 0.59,0.93). Subgroup analysis on cataract types determined that the significantly decreased risk of nuclear cataract in current HRT group (OR 0.72; 95%CI: 0.61,0.85) and also a critically reduced risk of nuclear cataract in ever HRT group (OR 0.80; 95% CI: 0.64,1.01) were found among case-control or cross-sectional studies, as compared with non-HRT group. No association of HRT with risk of cortical and posterior subcapsular cataract was observed.

CONCLUSIONS

The results of present meta-analysis indicate that postmenopausal hormone use may play a protective role in cataract development.

Racial differences in lens opacity incidence and progression: the Salisbury Eye Evaluation (SEE) study

PURPOSE

To evaluate racial differences in nuclear and cortical lens opacity incidence and progression over a 2-year period in an older American population.

METHODS

Prospective population-based cohort study of a multiethnic population of 2520 people (26% African-American and 74% Caucasian), 65 to 84 years of age, living in Salisbury, Maryland. Data at baseline included race, education level, past steroid use, smoking status, alcohol status, sunlight exposure, and history of hypertension and diabetes. Lens photographs were taken at baseline and at 2-year follow-up and were graded using the Wilmer grading scheme. Multiple logistic regression models were used to examine the independent associations between race, as well as other risk factors, and incidence and progression of cortical and nuclear opacities.

RESULTS

AFRICAN-AMERICANS HAD LOWER RATES OF NUCLEAR OPACITY INCIDENCE (ODDS RATIO [OR]: 0.52; 95% Confidence Interval [CI]: 0.35-0.76) and nuclear opacity progression (OR: 0.60; 95% CI: 0.38-0.92) compared with Caucasians. African-Americans had higher rates of cortical opacity incidence (OR: 1.90; 95% CI: 1.21-2.98) and cortical opacity progression (OR: 1.72; 95% CI: 1.21-2.45) compared with Caucasians. Additionally, nuclear opacity incidence was associated with age, female sex, and current smoking status. Nuclear progression was associated with past smoking and current smoking. Cortical opacity incidence was associated with female sex, Ultraviolet-B exposure, and a history of diabetes. Cortical opacity progression was associated with current smoking status.

CONCLUSIONS

Differences by race in the type of cataract incidence and progression, even adjusting for personal and environmental risk factors, deserve further exploration.

High affinity nuclear and nongenomic estradiol binding sites in the human and mouse lens

Estrogen is reported to be protective against cataracts in women and animal models. Immunodetection methods have identified the classic estrogen receptors (ER), ERα and ERβ, in human lens epithelial cells and their RNAs have been detected in the rat and human lens. To verify that estrogen binding occurs in the lens, sensitive [(125)I]-17β-estradiol binding analyses were performed on subcellular lens fractions from women (ages 39-78 years). The presence of high affinity estradiol binding sites in the nuclear, cytoplasmic, and membrane fractions indicate the lens is able to respond to estrogens, even up to age 78, although fewer binding sites were detected in the postmenopausal women. Additionally, due to the importance of mouse models in estrogen action and lens research, lenses from intact female mice were also analyzed. Both the C57BL/6 and FVB/N mouse strains also possessed high affinity binding sites in all three lens fractions. Furthermore, transcripts for ERα, ERβ, and G protein-coupled estrogen receptor (GPER; previously called GPR30) that bind estradiol with high affinity were expressed in the human and mouse lenses. These data provide the first evidence of GPER expression in the lens. Its role, functions, and subcellular location are currently unknown, but a G-shift assay in the membrane fractions of human and mouse lenses did not show evidence that estradiol induced classic G protein-coupled receptor activation. All three receptor transcripts were also detected in the lens capsule region isolated from female C57BL/6 mice, which is mainly comprised of epithelial cells. In contrast, only ERα and GPER were expressed in the cortex/nuclear region, which is primarily composed of differentiating and organelle-free fiber cells. No significant differences in specific estradiol binding and receptor RNA expression were observed in the lenses between male and female C57BL/6 mice. These findings indicate that the lens is an estrogen target tissue in both sexes. The identification of GPER, in addition to ERα and ERβ, in the lens also adds to the complexity of possible estrogen responses in the lens. Accordingly, the protective effects of estrogen in women and animals may be mediated by all three estrogen receptors in the lens. In addition, the similarities in binding and receptor RNA expression in the lenses of both species suggest that mice can be used to model estrogen action in the human lens.

Cigarette smoking, body mass index associated with the risks of age-related cataract in male patients in northeast China

AIM

To determine the association between cigarettes smoking, body mass index (BMI) and the risk of age-related cataract (ARC) in middle-aged and elderly men in Northeast China.

METHODS

A hospital-based case control study was conducted. Cases (n =362) were men who had surgically treated ARC, 45-85 years old; controls frequency-matched (n =362) were men who had been admitted to the same hospital as cases for other diseases not related with eye diseases. Cases and controls were matched with 1:1. The cases and controls were interviewed during their hospital stay, using a structured interviewer-administrated questionnaire that included information on sociodemographic characteristics, socioeconomic, lifestyle habits (tobacco smoking and alcohol consumption, etc.), anthropometric measures, personal medical history, and family history of ARC in first-degree relatives, and simultaneously BMI was calculated. The odds ratios (OR) and 95% confidence intervals (CI) of ARC were estimated using multiple logistic regression models.

RESULTS

After adjusting for age and multiple potential confounders, higher BMI was associated with an increased risk of ARC. Cigarette smoking, years smoking or moderate cigarette smoking (1-29 cigarettes per day) had no relation with the risk of ARC (P>0.05), although patients smoking ≥30 cigarettes per day had an elevated risk of ARC as compared with the non-smokers (OR=1.55, 95% CI; 1.16-2.85, P=0.026). Higher BMI was associated with an increased risk of ARC. Both overweight and obesity was associated with an obviously increased risk for surgically ARC (OR=1.55, 95% CI: 1.02-1.98, P=0.015 and OR=1.71, 95% CI: 1.32-2.39, P=0.013 respectively) compared to normal BMI. Then participants were grouped into quartiles of BMI (Q1 to Q4), compared to controls in the lowest quartile, the OR for cases in the highest quartile of BMI was 1.54 (OR=1.54, 95% CI: 1.08-2.46, P=0.022). The results of univariate analysis showed cigarette smoking was not associated with ARC formation for men with lower or normal BMI (P>0.05). Compared to the non-smokers, for men of overweight or obesity, cigarette smoking was associated with a significantly increased risk for surgically ARC (OR=2.00, 95% CI: 1.49-6.65, P=0.003 and OR=1.66, 95% CI: 1.63-13.21, P=0.002 respectively). Similarly, smokers in the highest quartile of BMI had approximately 1.5 times the risk of ARC as non-smokers in the lowest quartile (OR=1.46, 95% CI: 1.06-5.29, P<0.001). Followed multivariate models revealed that the association had never changed.

CONCLUSION

Current cigarette smoking is positively related to ARC only among those who smoking 30 or more cigarettes per day. For men who are both overweight and obesity, cigarette smoking is associated with a significantly increased risk for ARC.

Exogenous oestrogen exposure, female reproductive factors and the long-term incidence of cataract: the Blue Mountains Eye Study

PURPOSE

To assess the association between exogenous oestrogen exposure, female reproductive factors and the long-term incidence of cataract.

METHODS

People aged 49+ years living in a defined geographic region were invited to participate in this prospective population-based survey. Of 2072 women (83% of those eligible) who were examined during 1992-1994 at baseline, around 75% of survivors were re-examined at 5- and 10-year follow-up visits. Lens photographs were assessed using the Wisconsin Cataract Grading System by masked graders. An interviewer-administered questionnaire was used at each visit to collect information on female reproductive factors and the use of the oral contraceptive pill and postmenopausal hormone replacement therapy.

RESULTS

After adjusting for age, smoking, socioeconomic status, steroid use, hypertension and diabetes, ever having used the oral contraceptive pill had a mild protective effect against incident cortical cataract (odds ratio 0.70, 95% confidence interval 0.50-0.98). However, hormone replacement therapy, age at menarche, age at menopause, duration of exposure to endogenous oestrogen, parity and type of menopause were not found to have significant associations with the incidence of any type of cataract or cataract surgery.

CONCLUSION

Apart from a weak protective association of oral contraceptive pill use and the development of cortical cataract, we found no significant longitudinal associations between exogenous oestrogen exposure, female reproductive factors and the long-term incidence of cataract in this older population-based cohort.

Epidemiology of cataract: accomplishments over 25 years and future directions

The purpose of this review is to highlight the advances made by epidemiologic research into cataract. Considerable progress has been made in characterizing phenotypes, determining the prevalence and incidence in various population groups, and understanding risk factors for cataract. Cataract surgery research has documented functional improvements following surgery and has identified aspects of surgery delivery that could be made. Cataract is an independent marker of early mortality, providing a possible system for studying the aging process. Promising future work in cataract epidemiology is highlighted. Despite the availability of cataract surgery, cataract is still the leading cause of blindness worldwide. From a public health standpoint, research that can identify ways to delay onset or progression, or achieve the holy grail of prevention of cataract, should remain a leading priority.

Effect of Estrogen on Radiation-Induced Cataractogenesis

Cataractogenesis is a widely reported late effect that is observed in patients receiving total-body irradiation (TBI) prior to bone marrow transplantation or radiotherapy for ocular or head and neck cancers. Recent studies indicate that estrogens may protect against age-related and drug-induced cataracts. Moreover, other reports suggest that estrogen possesses antioxidant properties. Since the effect of estrogen on radiation cataractogenesis is unknown, we wished to determine whether estrogen modulates radiation-induced opacification of the lens. Intact or ovariectomized Sprague-Dawley rats were treated with either 17-beta-estradiol or an empty silastic capsule. The right orbit was then irradiated with either 10 or 15 Gy of (60)Co gamma rays using a Leksell Gamma Knife, and lenses were examined at various times postirradiation with a slit lamp or evaluated for light transmission. We found that for ovariectomized rats irradiated with 15 Gy, the lens opacity and the incidence of cataract formation in the estradiol-treated group were significantly increased compared to the control group at the end of the 25-week period of observation. Cataract incidence was also high in irradiated eyes of ovary-intact animals at 25 weeks postirradiation but was greatly reduced in the ovariectomized control group, with less than half of irradiated eyes showing evidence of cataractogenesis. Thus, after irradiation with 15 Gy of gamma rays, estrogen increased the incidence of cataract formation. We also observed that although the incidence of cataract formation in rats irradiated with 10 Gy and receiving continuous estrogen treatment was not altered compared to rats in the control group that did not receive estrogen, the latent period for posterior subcapsular cataract formation decreased and the severity of the anterior cataract increased. Taken together, our data suggest that estrogen accelerates progression of radiation-induced opacification.

Risk factors for cataract subtypes waterclefts and retrodots: two case–control studies

Waterclefts and retrodots are independently associated with visual impairment, yet a review identified no data on risk factors.

PURPOSE

To investigate risk factors for these two human lens cataract subtypes.

METHOD

Two nested case-control studies: The host study comprised 1078 subjects (55 years) attending the Somerset and Avon Eye Study (SAES). In total, 197 watercleft cases (Oxford grade 0.2 in either eye) and 199 retrodot cases (Oxford grade 1.0 in either eye) were individually age/gender matched to controls. Detailed ophthalmic and potential risk factor data were collected, including body mass index (BMI), smoking, alcohol, diabetes, hypertension, analgesics, vitamin supplementation, nutrition, sunlight exposure, dehydration, hormonal (women), blood lipids, glucose, urea, creatinine, uric acid, and vitamin levels.

RESULTS

For waterclefts, univariable analysis identified BMI, alcohol intake, vitamin status, sunlight, urea, creatinine, and uric acid as possible risk factors. Multivariable analysis identified two independent associations. Total number of 'any' analgesics in the previous year: adjusted P<0.01 (U-shaped risk profile, unadjusted high vs medium use (=reference) OR 2.39, 95% CI 1.35-4.26 with medium use vs none (=reference) OR 0.43, 95% CI 0.26-0.72); total sunlight: adjusted P=0.03 (unadjusted highest exposure vs lowest (=reference) OR 3.25, 95% CI 1.11-9.50). For retrodots, univariable analysis identified alcohol, HRT, and lipids. Multivariable analysis identified two independent associations. Mean number of alcohol units consumed per month, adjusted P=0.02 and HDL cholesterol levels, adjusted P=0.02 (unadjusted ORs NS both).

CONCLUSION

This is the first available published information on risk factors for the human cataractous lens features waterclefts and retrodots.