Using Natural Language Processing to Identify Different Lens Pathology in Electronic Health Records

PURPOSE

Nearly all published ophthalmology-related Big Data studies rely exclusively on International Classification of Diseases (ICD) billing codes to identify patients with particular ocular conditions. However, inaccurate or nonspecific codes may be used. We assessed whether natural language processing (NLP), as an alternative approach, could more accurately identify lens pathology.

DESIGN

Database study comparing the accuracy of NLP versus ICD billing codes to properly identify lens pathology.

METHODS

We developed an NLP algorithm capable of searching free-text lens exam data in the electronic health record (EHR) to identify the type(s) of cataract present, cataract density, presence of intraocular lenses, and other lens pathology. We applied our algorithm to 17.5 million lens exam records in the Sight Outcomes Research Collaborative (SOURCE) repository. We selected 4314 unique lens-exam entries and asked 11 clinicians to assess whether all pathology present in the entries had been correctly identified in the NLP algorithm output. The algorithm's sensitivity at accurately identifying lens pathology was compared with that of the ICD codes.

RESULTS

The NLP algorithm correctly identified all lens pathology present in 4104 of the 4314 lens-exam entries (95.1%). For less common lens pathology, algorithm findings were corroborated by reviewing clinicians for 100% of mentions of pseudoexfoliation material and 99.7% for phimosis, subluxation, and synechia. Sensitivity at identifying lens pathology was better for NLP (0.98 [0.96-0.99] than for billing codes (0.49 [0.46-0.53]).

CONCLUSIONS

Our NLP algorithm identifies and classifies lens abnormalities routinely documented by eye-care professionals with high accuracy. Such algorithms will help researchers to properly identify and classify ocular pathology, broadening the scope of feasible research using real-world data.

Cataract Disease Detection by Using Transfer Learning-Based Intelligent Methods

One of the most common visual disorders is cataracts, which people suffer from as they get older. The creation of a cloud on the lens of our eyes is known as a cataract. Blurred vision, faded colors, and difficulty seeing in strong light are the main symptoms of this condition. These symptoms frequently result in difficulty doing a variety of tasks. As a result, preliminary cataract detection and prevention may help to minimize the rate of blindness. This paper is aimed at classifying cataract disease using convolutional neural networks based on a publicly available image dataset. In this observation, four different convolutional neural network (CNN) meta-architectures, including InceptionV3, InceptionResnetV2, Xception, and DenseNet121, were applied by using the TensorFlow object detection framework. By using InceptionResnetV2, we were able to attain the avant-garde in cataract disease detection. This model predicted cataract disease with a training loss of 1.09%, a training accuracy of 99.54%, a validation loss of 6.22%, and a validation accuracy of 98.17% on the dataset. This model also has a sensitivity of 96.55% and a specificity of 100%. In addition, the model greatly minimizes training loss while boosting accuracy.

Automatic cataract grading methods based on deep learning

BACKGROUND AND OBJECTIVE

The shortage of ophthalmologists in rural areas in China causes a lot of cataract patients not getting timely diagnosis and effective treatment. We develop an algorithm and platform to automatically diagnose and grade cataract based on fundus images of patients. This method can help government assisting poor population more accurately.

METHODS

The novel six-level cataract grading method proposed in this paper focuses on the multi-feature fusion based on stacking. We extract two kinds of features which can effectively distinguish different levels of cataract. One is high-level features extracted from residual network (ResNet18). The other is texture features extarcted by gray level co-occurrence matrix (GLCM). Then a frame is proposed to automatically grade cataract by the extracted features. In the frame, two support vector machine (SVM) classifiers are used as base-learners to obtain the probability outputs of each fundus image, and fully connected neural network (FCNN) are used as meta-learner to output the final classification result, which consists of two fully-connected layers.

RESULT

The accuracy of six-level grading achieved by the proposed method is up to 92.66% on average, the highest of which reaches 93.33%. The proposed method achieves 94.75% accuracy on four-level grading for cataract, which is at least 1.75% higher than those of the exiting methods.

CONCLUSIONS

Six-category cataract classification algorithm show that Multi-feature & Stacking proposed in this paper helps achieve higher grading performance and lower volatility than grading using high-level features and texture features respectively. We also apply our algorithm into four-level cataract grading system and it shows higher accuracy compared with previous reports.

The Lens Opacities Classification System III Grading in Irradiated Uveal Melanomas to Characterize Proton Therapy-Induced Cataracts

PURPOSE

To evaluate the use of the Lens Opacities Classification System III grading (LOCS III) for the characterization of radiation-induced cataract, and to correlate the proton beam projection onto the lens with cataract location and grade as defined by the LOCS III.

DESIGN

Prospective, interventional case series.

METHODS

Fifty-two consecutive patients with cataract following proton therapy were included. All cataracts were graded using LOCS III. Relationships between proton beam and cataract subtypes, as well as between dose, proportion of lens irradiated, and extent of cataracts, were assessed.

RESULTS

Tumor diameter, volume, stage, and equatorial tumor location were associated with extent of posterior subcapsular cataracts (PSC) that were diagnosed at a median (interquartile range) 36 months (22;83) after treatment. In multivariate analysis, the tumor volume (P < .01) and an equatorial tumor location (P = .01) were risk factors for extensive PSC. Lens irradiation was avoided in 10 patients. In the remaining 42 patients (81%), the extent of PSC significantly correlated with the dose to the lens receiving 10, 26, and 47 Gy (P = .03, P = .03, and P = .04, respectively), the dose to the lens periphery receiving 10 and 26 Gy (P = .02 and P = .02, respectively), and the dose to the ciliary body receiving 10 and 26 Gy (P = .03 and P = .02, respectively). Nuclear color significantly correlated with the dose to the ciliary body receiving 10 Gy (P = .03) and 26 Gy (P = .02). After adjustment of the results on tumor volume and tumor location, the volume of lens receiving 10 Gy (P = .04) and 26 Gy (P = .03) remained significantly associated with the extent of PSC.

CONCLUSIONS

Proton dose correlated with the occurrence of PSC and nuclear color cataracts as defined by LOCS III grading. Better characterization of cataracts with the LOCS III after irradiation may help to further fill gaps in the current understanding of the mechanisms of radiation-induced cataracts.

Correlations of Objective Metrics for Quantifying Dysfunctional Lens Syndrome With Visual Acuity and Phacodynamics

PURPOSE

To study the relationship between objective metrics for quantifying crystalline lens dysfunction with visual impairment and phacodynamics parameters in age-related nuclear cataracts.

METHODS

A total of 51 eyes (34 patients) with age-related nuclear cataract had phacoemulsification. The Dysfunctional Lens Index (0 to 10 points) was measured by a ray-tracing aberrometry (iTrace Visual Function Analyzer; Tracey Technologies, Houston, TX). The average lens density (0 to 100) was evaluated using a rotating Scheimpflug system (Pentacam HR; Oculus Optikgeräte GmbH, Wetzlar, Germany), and the nuclear opalescence score was subjectively assessed using the Lens Opacities Classification System III (LOCS III). The different parameters for evaluating crystalline lens dysfunction were correlated with preoperative corrected distance visual acuity (CDVA) and cumulative dissipated energy (CDE).

RESULTS

There was a negative linear correlation between the Dysfunctional Lens Index and the LOCS III nuclear opalescence and Scheimpflug-measured average density (r =-0.728 and r = -0.771, respectively; both P < .01). The preoperative CDVA was correlated with the Scheimpflug-measured lens nuclear density value (r = 0.612, P < .01) and Dysfunctional Lens Index score A (r =-0.670, P < .01). The CDE was more strongly correlated with Dysfunctional Lens Index and Scheimpflug-derived average density (r =-0.744 and r = 0.700, respectively; both P < .01) than with LOCS III nuclear opalescence (r = 0.646, P < .01).

CONCLUSIONS

The Dysfunctional Lens Index was correlated with the Scheimpflug-measured average density, subjective lens grading, and preoperative CDVA. This metric also presented the highest correlation with phacodynamics. Correlation with other clinical measures related to visual quality and impairment are still needed. [J Cataract Refract Surg. 2017;33(2):79-83.].

[Correlation between axial length and corneal curvature and spherical aberration]

Objective: To discuss the correlation between axial length and corneal curvature and corneal spherical aberration in a group of cataract patients with axial length greater than 24 mm. Methods: Retrospective case series. This study comprised 117 (234 eyes) age-related cataract patients. There were 51 men (43.59%) and 66 women (56.41%) with mean age of (69.0±8.7) years (range from 52.0 to 85.0 years). The average axial length was 27.6±1.8 (range from 24.2 to 31.9 mm). We devided them into four groups according to the axial length. A-scan was used to measure the axial length and Pentacam was used to get the corneal curvature and corneal spherical aberration of both anterior and posterior surface. kolmogorov-smirnov test was used to check the normal distribution. ANOVA test was used to compare eachcorneal parameter among different groups. Pearson correlation analysis was used to obtain the correlation of corneal parameters in groups. Results: There were correlations between the axial length and the anterior and posterior corneal curvature (r=-0.213, r=0.174, respectively, P<0.05). No correlation was found between the axial length and anterior or posterior corneal spherical aberration (r=-0.114, 0.055, respectively, P>0.05). Mean values of corneal anterior surface curvature were (45.26±1.60) D (group 1), (44.17±1.45) D (group 2), (44.40±1.99)D (group 3), and (44.53±1.69) D (group 4) respectively. Mean values of corneal posterior surface curvature were(-6.57±0.26)D (group 1), (-6.40±0.24)D (group 2), (-6.41±0.38)D (group 3), and (-6.43±0.26)D (group 4) respectively. There were significant difference of corneal anterior and posterior surface curvature among 4 groups (P=0.004, P=0.001). There was significant difference of corneal curvature of anterior surface in group 1 compared to group 2 and group 3(P<0.01, P=0.01). There was significant difference of curvature of posterior surface in group 1 compared to group 2 and group 3, respectively (P<0.01). Mean values of anterior surface corneal spherical aberration were (2.09±0.53) μm (group 1), (1.90±0.44) μm (group 2), (2.00±0.74) μm (group 3), and (1.78±0.52) μm (group 4) respectively. Mean values of posterior surface corneal spherical aberration were (2.69±1.15) μm (group 1), (2.46±1.16) μm (group 2), (2.92±2.51) μm (group 3), and (2.69±1.13) μm (group 4) respectively. No correlation was found in anterior and posterior surface corneal spherical aberration(P>0.05) among different groups. Conclusions: The eye with a longer axial length have a flatter cornea. Cornea fails to compensate for axial length elongation when the axial length is longer than 28mm. The corneal spherical aberration varies among individuals, which suggests us to do the customized measurement before cataract surgery to make a decision on choosing the aspherical intraocular lens. (Chin J Ophthalmol, 2017, 53: 255-259).

Objective Scatter Index: Working Toward a New Quantification of Cataract?

PURPOSE

To investigate the associations between clinical cataract classifications, quality of life (QOL), and the objective loss of ocular transparency in patients presenting with clinical cataracts.

METHODS

In this prospective, multicenter, cross-sectional study, 1,768 eyes of 1,768 patients (mean age: 72.5 years; range: 28 to 93 years) referred for cataract assessment were enrolled. Visual acuity was measured before slit-lamp examination to determine the severity of lens opacification using the Lens Opacities Classification System III. Patients were asked to complete the Visual Function Index (VF-14) questionnaire. Ocular transparency was quantified by Objective Scatter Index (OSI) and was measured by the HD Analyzer (Visiometrics SL, Terrassa, Spain). Association and categorical data analysis were performed between each measured parameter alongside cross-tabulation analyses to determine sensitivity and efficiency of the HD Analyzer.

RESULTS

High OSI levels corresponded slightly with a lower visual acuity value and corresponded better with lower VF-14 scores. OSI scores were strongly associated with cataract classification and severity. Cross-tabulation analysis revealed a high sensitivity and efficiency index for the OSI with these clinically validated parameters illustrating good agreement overall for the OSI in determining cataract.

CONCLUSIONS

The OSI measured by the HD Analyzer is a sensitive and efficient tool to be considered in the early detection of cataract in patients.

Correlational Analysis of Objective and Subjective Measures of Cataract Quantification

PURPOSE

To evaluate whether correlations exist between objective and subjective measures of vision quality as a consequence of cataract and whether this may qualify the Objective Scatter Index as a supplementary means of cataract assessment.

METHODS

A prospective multicenter, cross-sectional study was conducted in 10 centers across France in patients undergoing cataract extraction surgery (lens opacity evaluated with the Lens Opacities Classification System III). A quality of life assessment using the Visual Function Index-14 (VF-14) (14 questions scored from 0 to 4) and measurement of visual acuity and evaluation of the Objective Scatter Index (HD Analyzer, Visiometrics SL, Terrassa, Spain) to assess the alteration of light scatter were used as measures in the study.

RESULTS

The study included 1,768 eyes of 1,768 patients (mean age: 72.5 years; range: 28 to 93 years). The average OSI score was 4.97 ± 3.13 (range: 0.4 to 20.5). There was good correlation between visual acuity and OSI (r = -0.47, P < .001) and between OSI and VF-14 (r = -0.11, P < .001).

CONCLUSIONS

The results presented in this study confirm that the Objective Scatter Index has sufficient correlations with visual acuity and VF-14 to supplement existing cataract diagnosis in a large population encompassing a broad spectrum of cataract presentations.

Longitudinal Study of Age-Related Cataract Using Dynamic Light Scattering: Loss of α-Crystallin Leads to Nuclear Cataract Development

PURPOSE

To conduct a longitudinal study on age-related nuclear cataracts using dynamic light scattering (DLS) to determine if cataract progression is associated with loss of the unbound form of the lens molecular chaperone protein, α-crystallin.

DESIGN

Natural history and cohort study.

PARTICIPANTS

Patients 30 years of age or older of either gender seeking treatment at the Wilmer Eye Institute Cornea-Cataract Department.

METHODS

All patients underwent a comprehensive dilated eye examination every 6 months, including slit-lamp grading of their lenses using the Age-Related Eye Disease Study (AREDS) clinical lens grading system and obtaining an estimate of unbound α-crystallin level in the nucleus, the α-crystallin index (ACI), using the National Aeronautics and Space Administration-National Eye Institute DLS device. We used a random effects statistical model to examine the relationship of lens opacity changes over time with ACI changes.

MAIN OUTCOME MEASURES

α-Crystallin Index (ACI) and AREDS nuclear cataract grade.

RESULTS

Forty-five patients (66 eyes) 34 to 79 years of age with AREDS nuclear lens grades of 0 to 3.0 were followed up every 6 months for a mean of 19 months (range, 6-36 months). We found that lenses with the lowest baseline levels of ACI had the most rapid progression of cataracts, whereas lenses with higher ACI at baseline had no or slower cataract progression. Lenses that lost α-crystallin at the highest rates during the study also had faster progression of nuclear cataracts than lenses with a slower rate of ACI loss. Kaplan-Meier survival curves showed that lenses with the lowest initial ACI had the highest risk of undergoing cataract surgery.

CONCLUSIONS

This longitudinal study corroborates our previous cross-sectional study finding that higher levels of unbound α-crystallin as assessed by ACI are associated with lower risk of cataract formation and that loss of ACI over time is associated with cataract formation and progression. This study suggested that assessment of ACI with the DLS device could be used as a surrogate for lens opacity risk in clinical studies, and for assessing nuclear cataract events in studies where cataract development may be a side effect of a drug or device.

Automatic Feature Learning to Grade Nuclear Cataracts Based on Deep Learning

GOAL

Cataracts are a clouding of the lens and the leading cause of blindness worldwide. Assessing the presence and severity of cataracts is essential for diagnosis and progression monitoring, as well as to facilitate clinical research and management of the disease.

METHODS

Existing automatic methods for cataract grading utilize a predefined set of image features that may provide an incomplete, redundant, or even noisy representation. In this study, we propose a system to automatically learn features for grading the severity of nuclear cataracts from slit-lamp images. Local filters are first acquired through clustering of image patches from lenses within the same grading class. The learned filters are fed into a convolutional neural network, followed by a set of recursive neural networks, to further extract higher order features. With these features, support vector regression is applied to determine the cataract grade.

RESULTS

The proposed system is validated on a large population-based dataset of [Formula: see text] images, where it outperforms the state of the art by yielding with respect to clinical grading a mean absolute error ( ε) of 0.304, a 70.7% exact integral agreement ratio ( R0), an 88.4% decimal grading error ≤ 0.5 ( Re0.5 ), and a 99.0% decimal grading error ≤ 1.0 ( Re1.0 ).

SIGNIFICANCE

The proposed method is useful for assisting and improving clinical management of the disease in the context of large-population screening and has the potential to be applied to other eye diseases.

Evaluation of cataract-related risk factors using detailed classification systems and multivariate statistical methods

The well-known different morphological features observed in so-called senile cataract are probably symptoms of various pathogenetic mechanisms in the lens. In order to identify a relationship between type of cataract and special risk factors, a cataract classification system using Scheimpflug photography has been developed. Data of 288 cataract patients (case histories and blood chemistries) have been grouped according to differences in cataract morphology. The multivariate analyses showed the following five variables to be important and to contribute independently to the differentiation of cataract types: cholelithiasis, allergy, heart insufficiency, pneumonia, and age. A case-control study without consideration of cataract morphology showed the following variables to be important and to associate independently with the risk of developing cataracts: age, allergy, diabetes, hypotension, hypertension, use of analgesics, and coronary disease.

Cataract survey in the local area using photographic documentation

An epidemiological survey of cataract was performed in a limited local population. 1,020 individuals over 40 years of age were examined. The crystalline lens findings were documented by both Scheimpflug and retroillumination photography. Cataractous changes were classified into three groups according to early senile changes, incipient cataractous changes and only prominent cataractous changes. Forms of opacification were classified as cortical, subcapsular, nuclear, mixed type and others. The percent prevalence of cataracts including early senile changes was 33.9% in the 40-year-old population, 62.8% in the 50, 76.2% in the 60, 84.0% in the 70 and 100% for those in their 80s. Prominent cataractous opacification was 1.6% in the 40-year-old population, 3.1% for those in their 50s, 19.0% in their 60s, 28.6% in their 70s and 57.1% in their 80s, respectively. Until age 60, the type of opacification was mainly cortical alone; however, after age 70, cortical opacity accompanied by nuclear and/or capsular opacities increased. The pure nuclear type increased in individuals over 70.

Progress toward developing a cataract classification system

A cataract classification system is being developed based on a set of standard photographs. The system uses an ordinal scale ranging from 0 (no opacities) to 2 (definite opacities) to classify cataractous changes in the nuclear, cortical, and posterior subcapsular lens zones. The reproducibility of slitlamp-derived and photo-derived classifications using the system was evaluated. The reproducibility between 2 observers for slitlamp-derived classifications was very high (n = 60). The reproducibility within and among 4 photography readers was also good for photo-derived classifications (n = 100). Discrepancies were found between ratings derived from slitlamp examinations and from photographs; such discrepancies were most frequent for gradings of cortical opacities.

Sectional classification of cataract

It is of importance to epidemiologically explore the risk factors which will induce cataract. Both the sections of lenses and their grades of opacity were classified only on the basis of the findings by the slitlamp microscope in order to examine the cases with cataract. There are split ways for classification of the cases with cataract, but it would be of no meaning if the classification for this purpose is not generally utilized, no matter how detailed it may be. Therefore, a simplified method for classification was discussed in the present study. There were variations in the grades of opacity with the sections of the lens, and the variations give different effects upon the visual disturbances. Especially, it was conceived that the visual power would be affected by the opacity of the posterior cortex. Also, it was conceived that the opacity of the posterior cortex tends to advance faster.

Indo-US case-control study of senile cataract--design and development

Study design and development are presented for an investigation of risk factors for senile cataract in a collaborative Indo-US case-control study in New Delhi, India. This study emphasizes the relationship of nutritional status, as ascertained by biochemical assessment on plasma and red blood cells and by dietary history, to specific cataract types (nuclear, cortical, posterior subcapsular).

Preliminary evaluation of a simple photographic cataract classification for epidemiological surveys

A preliminary evaluation of the agreement between clinical and photographic cataract classification and its reproducibility by utilizing a very simple classification system is presented. Photographic classification was based on color Zeiss 75-SL transparencies. Results indicate that photo-derived cataract classification based on slitlamp photographs has good validity for nuclear opacities but tends to underestimate posterior subcapsular cataracts.

On the epidemiology of cataract in Bulgaria

Cataract prevalence in Bulgaria is a subject of current registration and of research studies. Our report deals with three basic sources: national statistics data, epidemiological study on cataract incidence, and clinical observation on risk factors. In 1985, 7.9 cataract cases per 1,000 population (over 15 years) have been registered. Cataract extractions increased from 6,972 (1980) to 8,050 (1984). Cataract prevalence study on 2.5 representative samples during the 1970 census in Bulgaria demonstrated 3.6% for urban and 2.5% for rural populations for 1 year of observation. The data showed a 10-fold increase when additional ophthalmologic examination of a given sample had been performed. The clinically based study of cataract characteristics and risk factors includes about 600 patients for a 1-year period. In this report the data according to sex and age distribution, type of cataract and the presence of systemic disease have been presented.

Presence and distribution of L-kynurenine aminotransferases immunoreactivity in human cataractous lenses

PURPOSE

To investigate the presence and distribution of l-kynurenine aminotransferases immunoreactivity in human and animal lenses during cataract formation.

METHODS

Immunohistochemistry was conducted using polyclonal antibodies against KAT I, KAT II and KAT III on sections of 26 anterior capsules from patients undergoing surgical treatment of anterior subcapsular cataract (ASC) and 22 cataractous lenses from human eyes enucleated because of choroidal malignant melanoma. Additionally, the eyes of 11-month-old DBA/2J mice (6 eyes) were investigated (with KAT I and II). Ten clear human lenses and four BL6 mice lenses were used as controls. Spatial immunoreactivity patterns of enzymes were compared with Periodic Acid - Schiff (PAS)-stained sections.

RESULTS

Immunohistochemical analysis revealed presence of KAT I, KAT II and KAT III in extracellular structures of all studied types of cataract in human eyes showing specific pattern of the stain. In cortical cataract, immunoreactivity was observed on cortical lens fibres. In nuclear cataract, KAT II revealed stronger and diffused staining than KAT I. Additionally, both KAT showed more pronounced staining at the edge of small clefts. In normal human lenses, KAT I, II and III, immunoreactivity was not observed. Presence of KAT I and KAT II in the intercellular substance of DBA/2J mice cataract was observed. In BL6 mice lenses without cataract, only weak KAT I and KAT II staining was observed.

CONCLUSIONS

Presence of l-kynurenine aminotransferases in extracellular matrix (ECM) during human cataract formation suggests that products of l-kynurenine pathway might be involved in mechanisms of cataractogenesis.

Correlation between contrast sensitivity and the lens opacities classification system III in age-related nuclear and cortical cataracts

BACKGROUND

Contrast sensitivity (CS) testing can detect differences in functional vision and is highly correlated with visual performance. This study was designed to investigate the association between CS and the grading score using the lens opacities classification system (LOCS) III as well as the association between CS and visual acuity (VA) in nuclear or cortical age-related cataract (ARC) patients.

METHODS

A total of 270 eyes with ARC and 30 control eyes were divided into nuclear opacity (NO), nuclear color (NC), cortical cataract (C) based on LOCS III. The CS values measured at all spatial frequencies under photopic and glare conditions that resulted in contrast sensitivity function (CSF) were evaluated, and LogMAR VA was tested with the Early Treatment Diabetic Retinopathy Study (ETDRS) chart. The correlation between CSF and LOCS III grading scores, and between CSF and LogMAR VA were analyzed.

RESULTS

Compared to the controls, CSF of the nuclear or cortical ARC significantly declined. There are significant correlation between CSF and LogMAR VA, and between CSF and LOCS III grading scores. Compared to the VA, a stronger correlation existed between CSF and LOCS III grading score than that of LogMAR VA and LOCS III grading score. CS at some spatial frequencies is significantly influenced with LOCS III grading score.

CONCLUSIONS

CSF significantly declined with the increasing ARC grading scores. Comparing to VA, CSF reflected the severity of cataract more comprehensively. CS at low spatial frequency is significantly influenced by ARC. Therefore, CS is more precise than VA in assessing the visual function of ARC patients.

The prevalence of cataract in a population with and without type 2 diabetes mellitus

PURPOSE

To evaluate the prevalence and risk factors of lens opacities in a geographically defined population of subjects with type 2 diabetes mellitus compared with a control population.

METHODS

Subjects in the community of Laxå with a diagnosis of type 2 diabetes mellitus (n = 275) and a control group (n = 256) participated in the study. Lens opacities were graded with Lens Opacities Classification System II in all participants. Lens Opacities Classification System score ≥ 2 was considered as significant lens opacity. Anthropometric and blood chemistry data were collected for all participants in connection with the eye examination. For the diabetic population, yearly updated information on glucose control, blood pressure and body mass index was available through medical records from diabetes diagnosis until the time of the eye examination.

RESULTS

The prevalence of significant cortical, posterior subcapsular and nuclear cataract was 65.5%, 42.5% and 48.0%, respectively, in the type 2 diabetes population in Laxå. In logistic regression analyses, all types of lens opacities were strongly associated with age (p < 0.0001). Cortical lens opacity was also associated with a diagnosis of diabetes (p < 0.0001), posterior subcapsular lens opacity with HbA1c (p < 0.0001) and nuclear lens opacity with female gender and higher heart rate (both p = 0.0004). In the diabetic population, all types of cataract were likewise strongly associated with age (p < 0.0001), posterior subcapsular cataract with HbA1c (p = 0.0032), nuclear cataract with female gender (p = 0.0002) and higher heart rate (p = 0.0008).

CONCLUSIONS

  Our study shows that cortical cataract is associated with diabetes mellitus, not necessarily defined by glucose control, whereas posterior subcapsular cataract is associated with glucose levels. Nuclear cataract is not associated with diabetes mellitus, but is more frequent in women and is also associated with higher heart rate.

The Pyhäjärvi Cataract Study II. Criteria for cataract surgery

PURPOSE

It is necessary to develop tools for patient selection to target cataract surgery to patients with the best expected outcomes. We used visual acuity, visual functioning 14 (VF-14) test, the 15-dimension health-related quality-of-life questionnaire (15D) and the New Zealand priority criteria to evaluate the criteria for cataract surgery in a post hoc setting.

MATERIAL AND METHODS

Ninety-three consecutive patients living in a defined rural area in Finland had cataract surgery as a part of the Pyhäjärvi Cataract Study in 2003. Success of cataract surgery was defined as improvement of visual acuity by at least 2 lines and/or improvement of visual function measured by questionnaires.

RESULTS

The patients with a visual acuity of 0.30 logMAR (0.5 Snellen decimal) or worse in the better eye and/or 0.52 logMAR (0.3 Snellen decimal) in the worse eye had successful surgery in 59-83% of cases depending on the definition of success. When subjective judgement was added, the success rates varied between 63% and 91%.

CONCLUSION

Setting indication criteria, it seems sufficient to use two global questions in addition to visual acuity: one on the subjective view on disability, and one on a more neutral view on visual function, such as the 15D item on vision. The VF-14 did not perform any better than the single item counterparts.

The impact of cataract on the quantitative, non-invasive assessment of retinal blood Flow

PURPOSE

The aim of the study was to determine the impact of cataract on the quantitative, non-invasive assessment of retinal blood flow assessed by bidirectional laser Doppler flowmetry and simultaneous vessel densitometry.

METHODOLOGY

Ten patients scheduled for extracapsular cataract extraction using phacoemulsification and intraocular lens implantation between the ages of 61 and 84 (mean age 73 years, SD ± 8) were prospectively recruited. Two visits were required to complete the study; one visit prior to extracapsular cataract extraction and one at least 6 weeks after the surgery to allow for sufficient postoperative recovery. The severity of cataract was documented using the Lens Opacity Classification System (LOCS, III) at the first visit. Retinal arteriolar hemodynamics were measured at both visits using the high-intensity setting of the Canon Laser Blood Flowmeter.

RESULTS

All eyes showed no clinical signs of postoperative intraocular inflammation. The quantitative assessment of retinal arteriolar diameter and blood flow were reduced following extracapsular cataract extraction (Wilcoxon signed-rank test, p = 0.022 and p=0.028, respectively); however, centreline blood velocity was not significantly changed (Wilcoxon signed-rank test, p=0.074). Intraocular pressure was unchanged pre- and postcataract extraction.

CONCLUSIONS

Retinal vessel densitometry assessment in the presence of cataract results in the erroneous elevation of the diameter measurement and thereby the calculation of blood flow. The bidirectional Doppler assessment of blood velocity appears to be more robust to light scatter induced by cataract. Care needs to be exercised in the interpretation of studies of retinal vessel diameter or blood flow that utilize similar densitometry techniques.

Fasting blood glucose levels and the long-term incidence and progression of cataract -- the Blue Mountains Eye Study

PURPOSE

To assess the associations between fasting blood glucose and the long-term incidence and progression of cataract.

METHODS

A total of 3654 persons aged 49+ years were examined at baseline with fasting blood glucose measured, and 2454 re-examined after 5 and/or 10 years. Lens photographs from each visit were used to assess cataract incidence and progression. Associations between baseline fasting blood glucose and incidence and progression of cortical, nuclear and posterior subcapsular (PSC) cataract were assessed using discrete logistic regression and change-point models.

RESULTS

After adjusting for potential confounders, baseline fasting blood glucose was associated with the 10-year incidence of cortical cataract with a threshold at blood glucose level of 6.0 mm (odds ratio [OR] 1.79, 95% confidence interval [CI] 1.25-2.57 for fasting glucose ≥6.0 mm compared to fasting glucose <6.0 mm). Each 1.0 mm increase in fasting glucose was also associated with higher 5-year progression of PSC (OR 1.25, 95% CI: 1.15-1.35), 10-year progression of cortical (OR 1.14, 95% CI: 1.01-1.27) and nuclear (OR 1.20, 95% CI: 1.01-1.43) cataract, with no thresholds detected.

CONCLUSIONS

In this primarily nondiabetic older population, baseline fasting blood glucose was associated with the long-term incidence of cortical cataract and long-term progression of all three cataract subtypes.

Performance of three biometry devices in patients with different grades of age-related cataract

PURPOSE

The new Lenstar biometry device was compared in a typical clinical setting to the IOL-Master and Visante-OCT.

METHODS

Fifty-one eyes of 51 patients with age-related cataract were examined with Lenstar LS900 (Haag Streit AG) biometer, IOL-Master V.5 (Carl Zeiss Meditec AG) and Visante-OCT (Carl Zeiss Meditec AG) before cataract surgery. Central corneal thickness (CCT), anterior chamber depth (ACD), keratometry readings of flattest and steepest meridian (K), corneal radius (R) and axial length (AL) values were correlated. Cataracts were graded according to the Lens Opacities Classification System III (LOCS) regarding nuclear colour (NC), nuclear opalescence (NO), cortical (C) and posterior subcapsular (P) cataract.

RESULTS

Mean values and standard deviations for AL, K and R was 23.66 ± 1.23 mm and 23.67 ± 1.26 mm, 43.24 ± 1.69 dpt and 43.16 ± 1.71 dpt, 7.68 ± 0.29 mm and 7.70 ± 0.28 mm with the IOL-Master and with the LS900, respectively (r = 0.99 and p = 0.76, r = 0.99 and p = 0.029, r = 0.89 and p = 0.14, respectively). Visante-OCT demonstrated highest values of three devices regarding to ACD followed by Lenstar LS900 and IOLMaster. Axial length measurements were unfeasible in 10% of the cases (five patients) and this significantly correlated with the presence of posterior subcapsular cataract of LOCS III grade 4.0 or higher.

CONCLUSIONS

IOL-Master, Lenstar LS900 and AC–OCT proved to be excellent non-contact measurement methods in eyes with age-related cataract. Nevertheless, ultrasound biometry is still required for cases with dense posterior subcapsular cataract.

Morphologic changes in the anterior chamber in patients with cortical or nuclear age-related cataract

PURPOSE

To assess and compare the morphologic changes in the anterior segment in eyes with nuclear or cortical age-related cataract using Scheimpflug imaging.

SETTING

Peking University People's Hospital, Beijing, China.

DESIGN

Case-control study.

METHODS

Patients with nuclear or cortical age-related cataract were recruited. The grade of nuclear opalescence or cortical opacity was assessed using the Lens Opacities Classification System III (LOCS III). A group of elderly subjects with a clear lens and normal vision served as the control group. Anterior chamber depth (ACD), anterior chamber volume (ACV), and lens thickness were evaluated using Scheimpflug imaging (Pentacam).

RESULTS

Two hundred sixty-nine patients (330 eyes) were recruited. Thirty eyes were enrolled for each nuclear opalescence and cortical grade. The control group comprised 30 eyes (19 subjects). In eyes with age-related cataract, lens thickness increased with an increase in cortical opacity, whereas the ACD and ACV values decreased. The ACD was inversely correlated with LOCS III grades for nuclear opalescence (r = -0.197, P = .004), nuclear color (r = -0.195, P = .005), and cortical opacity (r = -0.508, P<.005). There were significant differences in lens thickness, ACD, and ACV between nuclear color, nuclear opalescence, and cortical opacity for LOCS III grades 3, 4, and 5, respectively.

CONCLUSIONS

There were significant differences in lens thickness, ACD, and ACV between nuclear and cortical age-related cataracts. The ACD decreased more in eyes with cortical cataract, suggesting that the risk for angle-closure glaucoma may be greater in cases of cortical opacity in which lens expansion is greater.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

The epidemiology of cataract: a study in Greece

PURPOSE

We conducted a case-control study to identify risk factors for cataract in the Mediterranean Greek population. Three hundred and fourteen cases and 314 frequency-matched controls of both genders, aged 45-85, attending the ophthalmology department of a major teaching hospital in Athens, Greece, were included in the study.

METHODS

Cases were medically diagnosed and classified. Controls were healthy visitors without cataract. A detailed questionnaire, covering demographic, socioeconomic, somatometric, lifestyle and medical history variables, provided data on possible risk factors for cataract. Analyses were conducted through multiple logistic regression.

MAIN OUTCOME MEASURES

Cataract overall and by type: nuclear, cortical and posterior subcapsular (PSC).

RESULTS

  Statistically significant increased risk for cataract overall was found for current (OR = 1.99, 95%CI: 1.23-3.23) and ex-smokers (OR = 1.64, 95%CI: 1.02-2.70), history of coronary heart disease (OR = 2.25, 95%CI: 1.43-3.55), family history of ophthalmologic diseases (OR = 1.51, 95%CI: 1.03-2.20) and higher sunlight exposure at the beach (OR = 2.26, 95%CI: 1.37-3.72) as well as at work (OR = 2.03, 95%CI: 1.32-3.12). Use of measures protecting against sunlight at the beach, i.e. hat (OR = 0.58, 95%CI: 0.39-0.85) and vision repair spectacles (OR = 0.44, 95% CI: 0.30-0.65), were associated with reduced risk. RESULTS for cataract overall were also evident for the nuclear type and in most circumstances for PSC type, but were only suggestive for the cortical type of cataract.

CONCLUSION

We identified certain possible risk factors for age-related cataract. In a Mediterranean Greek population, we found that smoking, use of cortisone drops, cardiovascular heart disease and sunlight exposure increase the risk for cataract, while use of hat and vision repair spectacles act protectively.

Outcome of dual infusion through irrigating chopper in conventional phacoemulsification

OBJECTIVE

To determine the operative advantage in terms of minimizing the complications following conventional phaco surgery with dual infusion through irrigating chopper.

METHODS

A Randomized Controlled Clinical Trial (RCCT) was conducted in the Ophthalmology Unit-III, Sindh Government Lyari General Hospital and DUHS and Al-Noor Eye Hospital Karachi, from March 2008 to February 2009. A total of 200 eyes with nuclear/cortico-nuclear cataract on Lens Opacity Classification System III underwent phacoemulsification. In all 100 eyes in group A were randomized to have conventional phacoemulsification with dual infusion technique through irrigating chopper and another 100 eyes in group B by conventional phaco surgery. Outcomes in two groups were judged by amount of Ringer's Lactate used, stability of anterior chamber and number of complications observed.

RESULTS

Rate of intra-operative complications was lower in group A as compared to group B (p=0.002). Anterior chamber depth was maintained in all cases of group A while it collapsed in 9 cases of group B which was highly significant (p=0.003). Mean amount of Ringer's Lactate used in group A was 260.2 +/- 55.07 ml and 195.8 +/- 35.0 ml in group B, which was significantly high (p<0.001).

CONCLUSION

Dual infusion through irrigating chopper serves triple function of irrigation, chopping and additional separate distant infusion. It improves anterior chamber stability and compensates surge and operative advantage to surgeon.

Effect of cataract on electroretinographic response

OBJECTIVE

To study the effect of cataract on electroretinographic responses.

MATERIAL AND METHOD

Thirty subjects with dense cataracts underwent electroretinogram (ERG) recordings before and after cataract surgery, using RETIport32 (Roland Instruments, Germany). The degree of cataract was classified according to the Lens Opacities Classification System III (LOCS III). No significant eye diseases were noted in all subjects. Following the International Society for Clinical Electrophysiology of Vision (ISCEV), scotopic, mesopic, photopic, oscillatorypotentials and 30 Hz flicker ERG responses were recorded. The mean amplitudes of a- and b-waves, pre and post-cataract surgery were analyzed using the paired t-test.

RESULTS

Following cataract surgery, most of the ERG responses were slightly increased but the difference was not statistically significant. However, the mesopic b-wave amplitude was decreased significantly after cataract surgery.

CONCLUSION

Most of the ERG waves after cataract surgery were slightly higher than pre-operative waves, but the differences were not statistically significant. The ERG remains a reliable guide in evaluation of the visual prognosis before cataract surgery.

Lens opacity and refractive influences on the measurement of retinal vascular fractal dimension

PURPOSE

To examine the influence of lens opacity and refraction on the measurement of retinal vascular fractal dimension (Df).

METHODS

  Optic disc photographs (right eyes) of 3654 baseline Blue Mountains Eye Study participants (aged 49-97) were digitized. Retinal vascular Df was quantified using a computer-based program. Summated severity scores for nuclear, cortical and posterior subcapsular (PSC) cataract were assessed from lens photographs. Refraction data were converted to spherical equivalent refraction (SER), as sum spherical plus 0.5 cylinder power. Axial length was measured at 10-year follow-up examinations using an IOL master.

RESULTS

  Mean Df of the retinal vasculature was 1.444±0.023 for 2859 eligible participants. Increasing lens opacity scores were associated with significant reduction in Df (β=-0.0030, p<0.0001). Both cortical and PSC cataract involving central lens area were associated with reduced Df, after controlling for confounding factors (p(trend) ≤0.0105). Increasing myopia severity was associated with reduced Df after adjusting for lens opacity scores and other confounders (p(trend) <0.0001). The slope of Df decrease per SER reduction was 0.0040 in eyes with SER≤-4D, compared to -0.0016 in eyes with SER>-4D. For axial length quintiles, there were no significant differences in mean Df in all groups except a reduction in the fifth quintile (axial length ≥24.15mm) (all p<0.05).

CONCLUSION

  Ocular media opacity independently influenced retinal vascular Df measurement, but we found no evidence supporting any refractive axial magnification effect on this measure. Myopic refraction ≤-4D was associated with a reduction in Df, suggesting rarefaction of retinal vasculature associated with high myopia.

Evaluation of the age-related eye disease study clinical lens grading system AREDS report No. 31

PURPOSE

To examine the grading (interrater) reliability of the Age-Related Eye Disease Study (AREDS) Clinical Lens Grading System (ARLNS).

DESIGN

Evaluation of diagnostic test or technology.

PARTICIPANTS

One hundred fifty volunteers (284 eyes).

METHODS

Participants with lens opacities of varying severity were independently graded at the slit lamp for cataract severity by 2 examiners (retinal or anterior segment specialists) using the ARLNS, which employs 3 standard photographs of increasing severity for classifying each of the 3 major types of opacity. Lens photographs were taken and graded at a reading center using the more detailed AREDS System for Classifying Cataracts from photographs.

MAIN OUTCOME MEASURES

The Pearson correlation, weighted-kappa, and limits-of-agreement statistics were used to assess the interrater agreement of the gradings.

RESULTS

Examinations were performed on 284 lenses (150 participants). Tests of interrater reliability between pairs of clinicians showed substantial agreement between clinicians for cortical and posterior subcapsular opacities and moderate agreement for nuclear opacities. A similar pattern and strength of agreement was present when comparing scores of retinal versus anterior segment specialists. Interrater agreement between clinical and reading center gradings was not as great as inter-clinician agreement.

CONCLUSIONS

Interrater agreements were in the moderate to substantial range for the clinical assessment of lens opacities. Inherent differences in cataract classification systems that rely on slit lamp vs photographic assessments of lens opacities may explain some of the disagreement noted between slit lamp and photographic gradings. Given the interrater reliability statistics for clinicians and the simplicity of the grading procedure, ARLNS is presented for use in studies requiring a simple, inexpensive method for detecting the presence and severity of the major types of lens opacities.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Four-year incidence and progression of lens opacities: the Los Angeles Latino Eye Study

PURPOSE

To estimate the 4-year incidence and progression of lens opacities.

DESIGN

Population-based longitudinal study.

METHODS

A total of 4658 adult Latinos from Los Angeles County were examined at baseline and 4-year follow-up. Examination included assessment of lens opacities using the Lens Opacities Classification System II (LOCS II). Incidences of cortical, nuclear, and posterior subcapsular opacities (with LOCS II scores >or=2) were defined as opacity development in persons without that opacity at baseline. Single and mixed opacities were defined in persons without any opacity at baseline. Incidence of all lens changes included development of at least 1 opacity or cataract surgery among those without any opacity at baseline. Four-year progressions were defined as increase of >or=2 in LOCS II score.

RESULTS

The 4-year incidence of all lens opacities was 14.2%. Four-year incidence of cataract surgery was 1.48%. The incidences were 4.1% for cortical-only, 5.8% for nuclear-only, 0.5% for PSC-only, and 2.5% for mixed. The incidences for any opacities were 7.5% for cortical, 10.2% for nuclear, and 2.5% for PSC. Incidence increased with age (P < .0001 for all). The progressions were 8.5% for cortical, 3.7% for nuclear, and 2.9% for PSC opacities.

CONCLUSIONS

Our Latino population had a higher incidence of nuclear than cortical opacities, but a greater progression of cortical than nuclear opacities. Incidence and progression of PSC was low. Additional understanding of the natural history and progression of various lens opacities will give us a better understanding of the pathogenesis and management of lens opacities.

Ocular risk factors for age-related macular degeneration: the Los Angeles Latino Eye Study

PURPOSE

To assess the association between ocular factors and age-related macular degeneration (AMD) in Latinos.

DESIGN

Population-based, cross-sectional study of 6357 self-identified Latinos aged 40 years and older.

METHODS

Ophthalmic examination included subjective refraction, measurement of axial length, evaluation of iris color, Lens Opacities Classification System II (LOCS II) grading of cataracts, and stereoscopic macular photographs for AMD lesions. Generalized estimating equation analysis incorporated data from both eyes to estimate odds ratios (OR) adjusted for covariates.

RESULTS

After controlling for confounders (age, gender, and smoking), prior cataract surgery was associated with advanced AMD (OR, 2.8; 95% CI, 1.01, 7.8), increased retinal pigment (OR, 1.6; 95% CI, 1.02, 1.5), and retinal pigment epithelial depigmentation (OR, 2.2; 95% CI, 1.1, 4.4). The presence of any lens opacity was associated with soft drusen (OR, 1.2; 95% CI, 1.002, 1.5). Longer axial length (per mm) was associated with decreased odds of soft drusen, increased retinal pigment, and geographic atrophy (GA) (ORs, 0.8 [95% CI, 0.7, 0.9], 0.8 [95% CI, 0.7, 0.9], 0.7 [95% CI, 0.5, 0.9], respectively). Myopia was inversely associated with soft drusen (OR, 0.8; 95% CI, 0.7, 0.99). Lighter-colored irises were associated with GA (OR, 5.0; 95% CI, 1.0, 25.3).

CONCLUSIONS

Cross-sectional associations of ocular factors such as cataract, cataract surgery, and refractive errors with early AMD lesions found in Latinos are consistent with those in non-Hispanic Whites. Additionally, prior cataract surgery was associated with advanced AMD.

[A classification of filmy opacities in the area of the iridolenticular diaphragm in artiphakia]

The proposed classification contains information on filmy opacities in the area of the iridolenticular diaphragm, namely: that on opacities in the posterior lenticular capsule and prelental papillary membranes. For the sake of clinical use convenience, the working classification also comprises data on the period of formation of filmy opacities, their degree, and the contact of filmy mass with the surface of an intraocular lens. The classification contributes to the correct planning of the technology of laser intervention and its volume and allows the treatment result to be predicted.

Binocular function in pseudophakic children

PURPOSE

There have been few reports on the binocular vision results in bilateral pseudophakic children. The author reports on the results of visual and binocular tests personally performed on patients who had the primary insertion of intraocular lenses following the removal of cataracts in their childhood.

METHODS

The author visited 4 different medical centers to perform monocular and binocular tests on 21 patients using the same equipment for sensory testing for binocularity on all patients before the history was abstracted from the clinical records. These patients were selected from a consecutive series and followed up for a minimum of 5 years by their ocular surgeons.

RESULTS

The mean patient age at surgery performed on the first eye was 6 years 4 months. The mean age at the date of the author's examination was 16 years 5 months, and the mean length of follow-up was 10 years 4 months. All but 2 patients had motor alignment within 8 prism diopters of orthotropia at near. Fusion and some stereopsis were found to be present in 15 patients, but only 4 of these patients demonstrated fine (60 seconds of arc or better) stereoacuity. Patients with fine vs gross stereoacuity were compared and found to be similar in type of cataract, age at first surgery, interval between surgeries, and length of follow-up and refraction, but to differ in the quality of best-corrected visual acuity.

CONCLUSION

Although satisfactory motor alignment, fusion, and some stereopsis are present in the majority of patients, fine stereoacuity is uncommon in pseudophakic children.

Prevalence of visually significant cataract and factors associated with unmet need for cataract surgery: Los Angeles Latino Eye Study

PURPOSE

To estimate the prevalence of visually significant cataract in a US Latino population and to report predisposing, enabling, need, and health behavior characteristics associated with the unmet need for cataract surgery (UNCS).

DESIGN

Population-based, cross-sectional study.

PARTICIPANTS

A total of 6142 Latinos 40 years and older from 6 census tracts in Los Angeles County, California.

METHODS

Participants completed an in-home interview and a comprehensive eye examination that included assessment of lens opacification, using the slit lamp-based Lens Opacities Classification System II (LOCS II), and best-corrected visual acuity. Visually significant cataract was defined by any LOCS II grading >or=2, best-corrected visual acuity <20/40, cataract as the primary cause of vision impairment, and self-reported vision of fair or worse. Because cataract surgery is not needed in all persons, participants with a visually significant cataract or prior cataract surgery in at least 1 eye composed the at-risk cohort needing cataract surgery. Unmet need for cataract surgery was defined as any person in the at-risk cohort who had at least 1 eye with a visually significant cataract. Univariate and stepwise logistic regression analyses were used to identify predisposing, enabling, need, and health behavior characteristics associated with UNCS.

MAIN OUTCOME MEASURES

Prevalence of visually significant cataract and odds ratios (ORs) for factors associated with UNCS.

RESULTS

Of 6142 participants who completed the interview and clinical examination, 118 (1.92%) had visually significant cataract in at least 1 eye. Of the 344 participants who have needed cataract surgery, 118 (34.3%) had UNCS. Independent factors associated with UNCS included health behavior: having last eye examination >or=5 years ago compared with <1 year ago (OR, 3.76; 95% confidence interval [CI], 1.71-8.25), and enabling factors: being uninsured (OR, 2.79; CI, 1.30-5.19), income less than $20,000 (OR, 2.60; CI, 1.40-5.56), and self-reported barriers to eye care (OR, 2.41; CI, 1.14-5.13).

CONCLUSIONS

Latinos in our study had a substantial UNCS. Because Latinos with specific health behavior and enabling characteristics were more likely to have UNCS, interventions aimed at modifying these characteristics may be beneficial in reducing the unmet need and thus reducing the burden of visual impairment related to cataract in the United States.

Association of lens opacities, intraocular straylight, contrast sensitivity and visual acuity in European drivers

PURPOSE

To study the relationship between lens opacity and intraocular straylight, visual acuity and contrast sensitivity.

METHODS

We investigated 2422 drivers in five clinics in different European Union (EU) member states aged between 20 and 89 years as part of a European study into the prevalence of visual function disorders in drivers. We measured visual acuity [Early Treatment Diabetic Retinopathy Study (ETDRS) chart], contrast sensitivity (Pelli-Robson chart) and intraocular straylight (computerized straylight meter). Lens opacities were graded with the Lens Opacities Classification System III (LOCS) without pupillary dilation. Participants answered the National Eye Institute Visual Functioning Questionnaire - 25.

RESULTS

Intraocular straylight was related more strongly to LOCS score than to both visual acuity and contrast sensitivity. Visual acuity and contrast sensitivity were correlated to each other well, but to intraocular straylight to a much lesser extent. Self-reported visual quality was best related to contrast sensitivity; night driving difficulty was best related to visual acuity.

CONCLUSION

Straylight is found to have added value for visual function assessment in drivers, whereas if visual acuity is known contrast sensitivity has limited added value.