Line Kessel

Post-cataract Prevention of Inflammation and Macular Edema by Steroid and Nonsteroidal Anti-inflammatory Eye Drops: A Systematic Review

PURPOSE Favorable outcome after cataract surgery depends on proper control of the inflammatory response induced by cataract surgery. Pseudophakic cystoid macular edema is an important cause of visual decline after uncomplicated cataract surgery. DESIGN We compared the efficacy of topical steroids with topical nonsteroidal anti-inflammatory drugs (NSAIDs) in controlling inflammation and preventing pseudophakic cystoid macular edema (PCME) after uncomplicated cataract surgery. PARTICIPANTS Patients undergoing uncomplicated surgery for age-related cataract. METHODS We performed a systematic literature search in Medline, CINAHL, Cochrane, and EMBASE databases to identify randomized trials published from 1996 onward comparing topical steroids with topical NSAIDs in controlling inflammation and preventing PCME in patients undergoing phacoemulsification with posterior chamber intraocular lens implantation for age-related cataract. MAIN OUTCOME MEASURES Postoperative inflammation and pseudophakic cystoid macular edema. RESULTS Fifteen randomized trials were identified. Postoperative inflammation was less in patients randomized to NSAIDs. The prevalence of PCME was significantly higher in the steroid group than in the NSAID group: 3.8% versus 25.3% of patients, risk ratio 5.35 (95% confidence interval, 2.94-9.76). There was no statistically significant difference in the number of adverse events in the 2 treatment groups. CONCLUSIONS We found low to moderate quality of evidence that topical NSAIDs are more effective in controlling postoperative inflammation after cataract surgery. We found high-quality evidence that topical NSAIDs are more effective than topical steroids in preventing PCME. The use of topical NSAIDs was not associated with an increased events. We recommend using topical NSAIDs to prevent inflammation and PCME after routine cataract surgery.

Age-related changes in the transmission properties of the human lens and their relevance to circadian entrainment

PURPOSE: To characterize age‐related changes in the transmission of light through noncataractous human lenses. SETTING: Department of Ophthalmology, Glostrup Hospital, Glostrup, Denmark. METHODS: The spectral transmission of white light was measured along the visual axis in the most central part of the lens in vitro in intact human donor lenses over a wide range of ages. RESULTS: The study evaluated 28 intact human donor lenses of 15 donors aged 18 to 76 years. Increasing age was associated with gradually decreasing transmission at all visible wavelengths, most prominently at shorter wavelengths. Empirical formulas describing the age‐related loss of transmission were created for each spectral color. At 480 nm, the absorption peak for melanopsin, transmission decreased by 72% from the age of 10 years to the age of 80 years. CONCLUSION: The age‐related decrease in spectral transmission through the human lens could be modeled by a simple algorithm that may be useful in the design of intraocular lenses that mimic the characteristics of the human lens and in studies of color vision, psychophysics, and melanopsin activation. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Antibiotic prevention of postcataract endophthalmitis: a systematic review and meta-analysis

Endophthalmitis is one of the most feared complications after cataract surgery. The aim of this systematic review was to evaluate the effect of intracameral and topical antibiotics on the prevention of endophthalmitis after cataract surgery. A systematic literature review in the MEDLINE, CINAHL, Cochrane Library and EMBASE databases revealed one randomized trial and 17 observational studies concerning the prophylactic effect of intracameral antibiotic administration on the rate of endophthalmitis after cataract surgery. The effect of topical antibiotics on endophthalmitis rate was reported by one randomized trial and one observational study. The quality and design of the included studies were analysed using the Cochrane risk of bias tool. The quality of the evidence was evaluated using the GRADE approach. We found high‐to‐moderate quality evidence for a marked reduction in the risk of endophthalmitis with the use of intracameral antibiotic administration of cefazolin, cefuroxime and moxifloxacin, whereas no effect was found with the use of topical antibiotics or intracameral vancomycin. Endophthalmitis occurred on average in one of 2855 surgeries when intracameral antibiotics were used compared to one of 485 surgeries when intracameral antibiotics were not used. The relative risk (95% CI) of endophthalmitis was reduced to 0.12 (0.08; 0.18) when intracameral antibiotics were used. The difference was highly significant (p < 0.00001). Intracameral antibiotic therapy is the best choice for preventing endophthalmitis after cataract surgery. We did not find evidence to conclude that topical antibiotic therapy prevents endophthalmitis.

Sleep disturbances are related to decreased transmission of blue light to the retina caused by lens yellowing.

STUDY OBJECTIVES Sleep pattern and circadian rhythms are regulated via the retinohypothalamic tract in response to stimulation of a subset of retinal ganglion cells, predominantly by blue light (450-490 nm). With age, the transmission of blue light to the retina is reduced because of the aging process of the human lens, and this may impair the photoentrainment of circadian rhythm leading to sleep disorders. The aim of the study was to examine the association between lens aging and sleep disorders. DESIGN Cross-sectional population based study. SETTING The study was performed at the Research Center for Prevention and Health, Glostrup Hospital, Denmark and at the Department of Ophthalmology, Herlev Hospital, Denmark. PARTICIPANTS An age- and sex-stratified sample of 970 persons aged 30 to 60 years of age drawn from a sample randomly selected from the background population. INTERVENTIONS Not applicable. MEASUREMENTS AND RESULTS Sleep disturbances were evaluated by a combination of questionnaire and the use of prescription sleeping medication. Lens aging (transmission and yellowing) was measured objectively by lens autofluorometry. The risk of sleep disturbances was significantly increased when the transmission of blue light to the retina was low, even after correction for the effect of age and other confounding factors such as smoking habits, diabetes mellitus, gender, and the risk of ischemic heart disease (P < 0.0001). CONCLUSIONS Filtration of blue light by the aging lens was significantly associated with an increased risk of sleep disturbances. We propose that this is a result of disturbance of photoentrainment of circadian rhythms.

Straight versus tortuous retinal arteries in relation to blood pressure and genetics

Background/aims: To assess the relative influence of genetic and environmental factors on retinal arterial tortuosity and the association between tortuosity and various health indices in healthy young to middle-aged persons. Methods: This cross-sectional study included 57 monozygotic and 52 dizygotic same-sex healthy twin pairs, aged 20 to 46 years, who were characterised by determination of retinal vessel diameters, arterial blood pressure, blood glucose, body mass index, smoking habits and retinal arterial tortuosity, using a three-level grading scale (straight, wavy, tortuous). Heritability of retinal arterial tortuosity was estimated using structural equation modelling. Results: Of 218 subjects, 79 (36.2%) had straight retinal arteries, 110 (50.5%) had wavy arteries, and 29 (13.3%) had tortuous arteries. Heritability of tortuosity was 82% (CI95 64, 92%), with unshared environmental factors accounting for the remaining 18% (CI95 8, 36%). Increasing values of mean arterial blood pressure and body mass index were both associated with decreasing levels of retinal arterial tortuosity. Conclusion: There was a large variation in tortuosity of retinal arteries in these healthy subjects and the predominant determinant was genetic influence, accounting for 82% of the observed variation in tortuosity.

Time-resolved and Steady-state Fluorescence Spectroscopic Studies of the Human Lens with Comparison to Argpyrimidine, Pentosidine and 3-OH-kynurenine¶

Abstract The intrinsic fluorescence from the human lens on excitation in the UV region, referred to as blue lens autofluorescence, increases with age or in the presence of diabetes. The present study reveals that the relative contribution of compounds responsible for the blue autofluorescence appears to be a constant with age. Three potential candidates for the blue fluorescence were also studied with respect to fluorescence spectroscopic properties. These were argpyrimidine and pentosidine, both advanced glycation end products, and 3-hydroxykynurenine (3-OH-kynurenine), a photooxidative derivative of tryptophan. It was shown that the spectral properties of argpyrimidine and pentosidine are compatible with the observed blue fluorescence of the human lens, whereas the fluorescence from 3-OH-kynurenine is negligible.

The relationship between body and ambient temperature and corneal temperature.

PURPOSE Exposure to elevated ambient temperatures has been mentioned as a risk factor for common eye diseases, primarily presbyopia and cataract. The aim of the present study was to examine the relationship among ambient, cornea, and body core temperature. METHODS The relation between corneal temperature and ambient temperature was examined in 11 human volunteers. Furthermore, corneal temperature was measured using a thermal camera during elevation of body core temperature in three human volunteers and four rats. RESULTS A linear relationship between corneal temperature and body temperature was found in the rat. For humans there was an initial linear increase in corneal temperature with increasing body temperature, but corneal temperature seemed to plateau at 36.5°C to 37.0°C despite a continued increase of body core temperature. A linear relationship between ambient and corneal temperature was found in humans but with a less steep slope than that between corneal and body core temperature. CONCLUSIONS Corneal temperature is estimated to reach the maximum of 36.5°C to 37.0°C at ambient temperatures between 32.0°C and 34.5°C. If there is a causal relationship between elevated eye temperature, cataract, and presbyopia, the incidence of these eye diseases is predicted to increase with global warming. Importantly, the strong association between corneal temperature and body core temperature indicates that frequent infections could also be considered a risk factor for age-related lens disorders.

Lens ageing as an indicator of tissue damage associated with smoking and non-enzymatic glycation--a twin study.

Abstract Aims/hypothesis. With ageing the long-lived proteins of the human lens undergo denaturation by non-enzymatic glycation. The denaturated proteins are fluorescent, a property that can be assessed in vivo by fluorometry. Our aim was to examine the relative contribution of hereditary and environmental effects on the accumulation of fluorescent compounds in the lens. Methods. We examined 59 monozygotic and 55 dizygotic healthy twin pairs recruited from a population-based register of twins. Lens autofluorescence was measured on the undilated eye. All subjects underwent an OGTT and information on smoking habits was obtained. The genetic and environmental effects were estimated by structural equation modelling. Results. Lens autofluorescence was related to age (R2=53%), current glucose homeostasis (R2=10%) and smoking habits (R2=10%). After adjusting for these factors, interindividual variation in lens autofluorescence was statistically attributable to hereditary factors by approximately 28% as well as shared environment by 58% and non-shared environment by 14%. The hereditary factor seems not to be linked to a genetic predisposition to diabetes. Conclusion/interpretation. The correlation in lens fluorescence was greater in monozygotic twins than dizygotic twins indicating a genetically predetermined susceptibility for the accumulation of fluorophores in the lens, the relative importance of which was found to increase with age. Since fluorophore formation in the lens is attributable to non-enzymatic glycation our results support that genetic characteristics to some degree determine the susceptibility to glycation related diabetes complications and ageing processes.

Intrinsically photosensitive retinal ganglion cell function in relation to age: A pupillometric study in humans with special reference to the age-related optic properties of the lens

BackgroundThe activity of melanopsin containing intrinsically photosensitive ganglion retinal cells (ipRGC) can be assessed by a means of pupil responses to bright blue (appr.480 nm) light. Due to age related factors in the eye, particularly, structural changes of the lens, less light reaches retina. The aim of this study was to examine how age and in vivo measured lens transmission of blue light might affect pupil light responses, in particular, mediated by the ipRGC.MethodsConsensual pupil responses were explored in 44 healthy subjects aged between 26 and 68 years. A pupil response was recorded to a continuous 20 s light stimulus of 660 nm (red) or 470 nm (blue) both at 300 cd/m2 intensity (14.9 and 14.8 log photons/cm2/s, respectively). Additional recordings were performed using four 470 nm stimulus intensities of 3, 30, 100 and 300 cd/m2. The baseline pupil size was measured in darkness and results were adjusted for the baseline pupil and gender. The main outcome parameters were maximal and sustained pupil contraction amplitudes and the postillumination response assessed as area under the curve (AUC) over two time-windows: early (0–10 s after light termination) and late (10–30 s after light termination). Lens transmission was measured with an ocular fluorometer.ResultsThe sustained pupil contraction and the early poststimulus AUC correlated positively with age (p = 0.02, p = 0.0014, respectively) for the blue light stimulus condition only.The maximal pupil contraction amplitude did not correlate to age either for bright blue or red light stimulus conditions.Lens transmission decreased linearly with age (p < 0.0001). The pupil response was stable or increased with decreasing transmission, though only significantly for the early poststimulus AUC to 300 cd/m2 light (p = 0.02).ConclusionsAge did not reduce, but rather enhance pupil responses mediated by ipRGC. The age related decrease of blue light transmission led to similar results, however, the effect of age was greater on these pupil responses than that of the lens transmission. Thus there must be other age related factors such as lens scatter and/or adaptive processes influencing the ipRGC mediated pupil response enhancement observed with advancing age.

Short wavelength light filtering by the natural human lens and IOLs – implications for entrainment of circadian rhythm

Purpose:  Photoentrainment of circadian rhythm begins with the stimulation of melanopsin containing retinal ganglion cells that respond directly to blue light. With age, the human lens becomes a strong colour filter attenuating transmission of short wavelengths. The purpose of the study was to examine the effect the ageing human lens may have for the photoentrainment of circadian rhythm and to compare with intraocular implant lenses (IOLs) designed to block UV radiation, violet or blue light.