[Intraoperative Complications in Cataract Surgery]. / Intraoperative Komplikationen der Kataraktchirurgie.

Cataract surgery is frequently and successfully performed in the developed world. The indications for the operation have shifted on one hand towards healthier patients seeking freedom from glasses and on the other hand towards more complex cases. How should the patient be informed? What complications can occur intraoperatively, and what treatment options are available for these complications?This article offers a focus on conditions such as zonulopathy and pseudoexfoliation that can pose challenges to cataract surgery. It discusses the use of specialized tools such as capsular tension rings and capsular hooks and precise maneuvers to minimize stress on weakened zonules in order to ensure in-the-bag fixation of the IOL.Furthermore, the article addresses appropriate actions towards intraoperative complications such as anterior or posterior capsule ruptures and loss of nuclear fragments into the vitreous cavity.Exploring innovative advancements, this article presents the latest alternatives for intracapsular lens fixation, such as sutureless scleral fixation and emerging lens designs in cases where there is insufficient capsular support.Ultimately, the primary objective remains delivering optimal outcomes even for complex cases, and minimizing post-surgical issues. Numerous tools and techniques are available.

Intraoperative complications of cataract surgery using a low-energy femtosecond laser: Results from a real-world high-volume setting.

In this study, we report data on intraoperative complications occurring after cataract surgery in a high-volume single-center setting using a low-energy, mobile femtosecond laser. We retrospectively reviewed the medical records of patients who underwent femtosecond laser-assisted cataract surgery (FLACS) in our hospital between August 2015 and December 2019. Among the sample of 1,806 eyes of 1,131 patients (903 left and 903 right eyes), the mean age was 75.8 years (range, 21-99 years). The overall intraoperative complication rate was 0.28% (n = 5), with three cases of anterior capsule tear (0.17%) and two cases of posterior capsule tear (0.11%). No further complications occurred. This study underlines the safety of low-energy femtosecond-assisted cataract surgery in a real-world setting with a very low rate of intraoperative complications.

Perioperative pupil size in low-energy femtosecond laser-assisted cataract surgery.

PURPOSE: To assess potential changes in pupil size during femtosecond laser-assisted cataract surgery (FLACS) using a low-energy laser system. METHODS: The pupil sizes of eyes undergoing FLACS were measured using the Ziemer LDV Z8 by extracting images from the laser software after each of the following steps: application of suction, lens fragmentation, and capsulotomy. Furthermore, the pupil diameters were measured based on preoperative surgical microscope images and after releasing the suction. Paired t-test and the two one-sided tests (TOST) procedure were used for statistical analyses. The horizontal and vertical pupil diameters were compared in each of the steps with preoperative values. RESULTS: Data were available for 52 eyes (52 patients, mean age 73.4 years, range 51-87 years). The equivalence between mean preoperative pupil size and status immediately after femtosecond laser treatment was confirmed (p<0.001; 95% confidence interval [-0.0637, 0.0287] for horizontal and p<0.001; 95% CI [-0.0158, 0.0859] for vertical diameter). There was statistically significant horizontal and vertical enlargement of pupil diameters between 0.15 and 0.24 mm during the laser treatment steps as compared with preoperative values (all p values <0.001). CONCLUSIONS: No progressive pupil narrowing was observed using low-energy FLACS. Although a suction-induced, slight increase in pupil area became apparent, this effect was completely reversible after removing the laser interface.

Femtosecond-Laser Assisted Surgery of the Eye: Overview and Impact of the Low-Energy Concept.

This article provides an overview of both established and innovative applications of femtosecond (fs)-laser-assisted surgical techniques in ophthalmology. Fs-laser technology is unique because it allows cutting tissue at very high precision inside the eye. Fs lasers are mainly used for surgery of the human cornea and lens. New areas of application in ophthalmology are on the horizon. The latest improvement is the high pulse frequency, low-energy concept; by enlarging the numerical aperture of the focusing optics, the pulse energy threshold for optical breakdown decreases, and cutting with practically no side effects is enabled.

Genome-wide association meta-analysis of corneal curvature identifies novel loci and shared genetic influences across axial length and refractive error.

Corneal curvature, a highly heritable trait, is a key clinical endophenotype for myopia - a major cause of visual impairment and blindness in the world. Here we present a trans-ethnic meta-analysis of corneal curvature GWAS in 44,042 individuals of Caucasian and Asian with replication in 88,218 UK Biobank data. We identified 47 loci (of which 26 are novel), with population-specific signals as well as shared signals across ethnicities. Some identified variants showed precise scaling in corneal curvature and eye elongation (i.e. axial length) to maintain eyes in emmetropia (i.e. HDAC11/FBLN2 rs2630445, RBP3 rs11204213); others exhibited association with myopia with little pleiotropic effects on eye elongation. Implicated genes are involved in extracellular matrix organization, developmental process for body and eye, connective tissue cartilage and glycosylation protein activities. Our study provides insights into population-specific novel genes for corneal curvature, and their pleiotropic effect in regulating eye size or conferring susceptibility to myopia.

[Femtosecond laser-assisted astigmatic keratotomy]. / Astigmatische Keratotomien mit dem Femtosekundenlaser.

BACKGROUND: For more than 100 years keratotomy has been in the focus of ophthalmology as a treatment option for correction of astigmatism. Femtosecond laser technology provides a new level of precision, standardization and control as well as completely new options, such as purely intrastromal incisions. METHOD: The current literature is summarized with respect to femtosecond laser-assisted astigmatic keratotomy (FSAK) in combination with cataract surgery, where less astigmatic correction is necessary as well as after corneal surgery, such as perforating keratoplasty, where higher astigmatic errors need to be corrected. CONCLUSION: The FSAK provides a safe treatment option for both scenarios although larger studies with longer follow-up are needed to improve currently available nomograms.

Choroidal thickness is associated with cardiovascular risk factors and cardiac health: the Gutenberg Health Study.

BACKGROUND: Choroidal thickness is associated with several cardiovascular parameters in case-control studies including patients with manifest disease. So far, it was unclear whether underlying cardiovascular risk factors or the continuum of heart failure may lead to alterations of the choroid. Therefore, our hypothesis was to test in a population-based study, whether choroidal thickness is associated with cardiovascular risk factors and heart disease. METHODS: A population-based cross-sectional study was carried out in Germany. A comprehensive medical examination including assessment of cardiovascular risk factors, echocardiography and ophthalmological examinations with spectral-domain optical coherence tomography of the choroid was performed. Subfoveal choroidal thickness as well as left ventricular ejection fraction (LVEF) and a surrogate marker for left ventricular end-diastolic pressure (E/e') were measured. Linear regression analyses were carried out to determine the relationship between subfoveal choroidal thickness and age, sex, body mass index, systolic blood pressure, dyslipidemia, HbA1c level, hematocrit, estimated glomerular filtration rate (eGFR), LVEF, E/e' and left ventricular mass index adjusted for ocular parameters. RESULTS: 1.742 subjects (48% females) with a mean age 59.3 ± 10.6 years were included in this study. Mean subfoveal thickness was 252 ± 77 µm (right eyes) and 255 ± 77 µm (left eyes). Unadjusted linear regression analysis revealed that subfoveal choroidal thickness is associated with sex, age, systolic blood pressure, hematocrit, eGFR, left ventricular end-diastolic pressure, left ventricular mass index (all p < 0.001) and dyslipidemia (p = 0.009). Adjusted linear regression only revealed age as associated parameter (p < 0.001). CONCLUSIONS: We did find evidence for an association between subfoveal choroidal thickness and cardiovascular risk factors which was mediated by aging.

[Intravitreal Therapy Combining Dexamethasone and Bevacizumab in Treating Radiation Retinopathy and Opticopathy]. / Kombinierte intravitreale Therapie mit Dexamethason und Bevacizumab bei Strahlenoptikopathie und -retinopathie.

Radiation Retinopathy is a progressive chronic disease triggered by ionising radiation and is characterised by vascular endothelial damage that can lead to macular edema, optic disc edema and proliferative retinopathy. We discuss a case of a patient with radiation retinopathy and optic disc edema who we treated with a combination of intravitreal bevacizumab and dexamethasone. After 3 injections of bevacizumab, and one of dexamethasone, the patient experienced a resolution of optic disc edema and a marked increase of his visual acuity and remained stable throughout the follow-up period.

Changes in Pupil Area during Low-energy Femtosecond Laser-assisted Cataract Surgery.

PURPOSE: To study the potential changes in pupil area within low-energy femtosecond-laser assisted cataract surgery (FLACS). METHODS: A retrospective assessment of the pupil size was performed in the eyes undergoing FLACS using the Ziemer LDV Z8. We measured the pupil diameters as part of the images taken preoperatively and at the completion of laser pretreatment (after releasing the suction). We calculated the pupil area in 40 eyes of 40 patients (14 right and 26 left eyes). The mean ± standard deviation (SD) of age of the patients was 74 ± 7.4 years (range: 51-87). Paired t-test was used for statistical analyses. Subgroups were built with reference to age and preoperative pupil area (smaller than or equal to the median versus larger than the median). RESULTS: The mean ± SD axial length, anterior chamber depth, white-to-white distance and lens thickness were 24.01 ± 1.47, 3.23 ± 0.4, 11.97 ± 0.49, and 4.59 ± 0.41 mm, respectively. The mean ± SD pupil area was 39.33 ± 7.1 mm 2 preoperatively and 39.3 ± 6.75 mm 2 after laser pretreatment. The mean ± SD change in pupil area was -0.03 ± 2.12 mm 2 . There were no statistically significant changes between preoperative and post-laser pupil areas (P = 0.93, 95% CI: -0.71 to 0.65). Comparisons within subgroups also did not detect pupil area reduction. CONCLUSION: This study did not detect statistically significant changes in pupil area after laser pretreatment using low-energy FLACS. This observation is in contrast to previous studies using other laser platforms.

Posterior segment eye lesions: prevalence and associations with ocular and systemic parameters: results from the Gutenberg Health Study.

BACKGROUND: To estimate the prevalence of posterior segment eye lesions and to identify their ocular and systemic associations within the Gutenberg Health Study (GHS) in Germany. METHODS: Assessment and grading of fundus images as well as physical examination and history taking were performed in the cross-sectional analysis of 15,010 subjects (aged 35-74 years) using standardised procedures to determine the prevalence and associations of various posterior segment eye lesions. RESULTS: Fundus photographs of both eyes were available for 12,782 (85.2%; 50% female) subjects. The prevalence weighted to the region of Mainz and Mainz-Bingen in Germany was for choroidal nevi 2.4%, drusen of the optic nerve head 0.2%, tilted discs 1.5%, chorioretinal scars suggestive of toxoplasmosis 0.2%, retinitis pigmentosa 0.04% and persistent hyaloid artery 0.02%. Choroidal nevi were positively associated with a history of myocardial infarction (OR = 2.7, 95% confidence interval 1.2-6.2, p value = 0.017). Tilted discs were positively associated with increased intraocular pressure (OR = 1.09 per mm Hg (1.02-1.16), p = 0.011) and negatively associated with smoking (OR 0.4 (0.3-0.7), p = 0.0022). Participants with tilted discs had a mean spherical equivalent of - 3.6 dioptres (standard deviation 4.0) compared with - 0.4 dioptres (2.4) to those without. CONCLUSION: Our study is-to the best of our knowledge-the first to determine the prevalence of drusen of optic nerve head among Caucasians, to show a positive association between tilted discs and increased intraocular pressure and questions a possible link between choroidal nevi and myocardial infarction. It also showed that participants with tilted discs had a lower mean spherical equivalent than those without.

Hypertension and multiple cardiovascular risk factors increase the risk for retinal vein occlusions: results from the Gutenberg Retinal Vein Occlusion Study.

OBJECTIVE: Although several risk factors for retinal vein occlusion (RVO) are known, what triggers RVO is unclear in many cases. We aimed to evaluate the relevance of multiple risk factors in patients with RVO. METHODS: The Gutenberg RVO Study is an observational case-control study that assessed thrombophilic, cardiovascular, ophthalmic, and drug-related risk factors in participants with RVO and the same number of matched controls. Conditional logistic regression analysis was chosen to estimate the risk of RVO due to several risk factors. RESULTS: Of 92 patients with RVO, 46 (50%) had central RVO, 31 (33.7%) had branch RVO, and 15 (16.3) had hemi-RVO. Systemic hypertension was associated with RVO [any RVO: odds ratio (OR): 1.81; 95% confidence interval (CI): 1.14-2.88; branch RVO: OR: 2.56; 95% CI: 1.08-6.10]. The most frequent combinations of risk factors were hypertension with dyslipidemia (33 of 92, 35.9%) and hyperhomocysteinemia and high levels of factor VIII (10 of 92, 10.9%). An increase in the risk sum score by one additional risk factor corresponded to ORs of 1.74 (95% CI: 1.31-2.32) for cardiovascular risk factors, 1.38 (95% CI: 1.04-1.82) for thrombophilic risk factors, and 1.43 (95% CI: 1.20-1.70) for the total number of risk factors for RVO. CONCLUSION: Cardiovascular risk factors are more important than other risk factors for the presence of RVO. The risk of RVO increased by approximately 40% with any additional risk factor and by 70% with any additional cardiovascular risk factor.

Association of ocular, cardiovascular, morphometric and lifestyle parameters with retinal nerve fibre layer thickness.

BACKGROUND: Glaucoma is a neurodegenerative disease, leading to thinning of the retinal nerve fibre layer (RNFL). The exact influence of ocular, cardiovascular, morphometric, lifestyle and cognitive factors on RNFL thickness (RNFLT) is unknown and was analysed in a subgroup of the Gutenberg Health Study (GHS). METHODS: Global peripapillary RNFLT was measured in 3224 eyes of 1973 subjects (49% female) using spectral-domain optical coherence tomography (SD-OCT). The association of age, sex, ocular, cardiovascular, morphometric, lifestyle and cognitive factors on RNFLT was analysed using Pearson correlation coefficient and fitting a linear mixed model. RESULTS: In the univariable analysis highest correlations were found for axial length (r = -0.27), spherical equivalent (r = 0.24), and glaucoma (r = -0.15) (p<0.0001, respectively). Other significant correlations with RNFLT were found for age, sex, intraocular pressure, systemic hypertension and systolic blood pressure, previous eye surgery, cholesterol, homocysteine, history of coronary artery disease, history of myocardial infarction, apnoea, diabetes and alcohol intake, p<0.05, respectively. Body length, body weight, BMI, diastolic blood pressure, blood glucose, HbA1c, history of apoplexy, cognitive function, peripheral artery disease, tinnitus, migraine, nicotine intake, central corneal thickness, and pseudophakia were not significantly correlated with RNFLT. The regression model revealed a significant relationship between RNFLT and age in decades (p<0.02), spherical equivalent (p<0.0001), axial length (p<0.0001), glaucoma (p<0.0001), tinnitus (p = 0.04), apnoea (p = 0.047), homocysteine (p = 0.05) and alcohol intake >10g/d for women and >20g/d for men (p = 0.02). Glaucoma, apnoea, higher homocysteine, higher alcohol intake and higher axial length as well as age were related to decreased RNFLT while higher spherical equivalent or history for tinnitus were related to thicker RNFL. CONCLUSION: RNFLT is related to age, ocular parameters and lifestyle factors. Considering these parameters in normative databases could improve the evaluation of peripapillary RNFLT. It is necessary to evaluate if a reduction of alcohol intake as well as the therapy of apnea or high homocysteine levels could positively influence RNFLT.

The Decreasing Prevalence of Nonrefractive Visual Impairment in Older Europeans: A Meta-analysis of Published and Unpublished Data.

TOPIC: To estimate the prevalence of nonrefractive visual impairment and blindness in European persons 55 years of age and older. CLINICAL RELEVANCE: Few visual impairment and blindness prevalence estimates are available for the European population. In addition, many of the data collected in European population-based studies currently are unpublished and have not been included in previous estimates. METHODS: Fourteen European population-based studies participating in the European Eye Epidemiology Consortium (n = 70 723) were included. Each study provided nonrefractive visual impairment and blindness prevalence estimates stratified by age (10-year strata) and gender. Nonrefractive visual impairment and blindness were defined as best-corrected visual acuity worse than 20/60 and 20/400 in the better eye, respectively. Using random effects meta-analysis, prevalence rates were estimated according to age, gender, geographical area, and period (1991-2006 and 2007-2012). Because no data were available for Central and Eastern Europe, population projections for numbers of affected people were estimated using Eurostat population estimates for European high-income countries in 2000 and 2010. RESULTS: The age-standardized prevalence of nonrefractive visual impairment in people 55 years of age or older decreased from 2.22% (95% confidence interval [CI], 1.34-3.10) from 1991 through 2006 to 0.92% (95% CI, 0.42-1.42) from 2007 through 2012. It strongly increased with age in both periods (up to 15.69% and 4.39% in participants 85 years of age or older from 1991 through 2006 and from 2007 through 2012, respectively). Age-standardized prevalence of visual impairment tended to be higher in women than men from 1991 through 2006 (2.67% vs. 1.88%), but not from 2007 through 2012 (0.87% vs. 0.88%). No differences were observed between northern, western, and southern regions of Europe. The projected numbers of affected older inhabitants in European high-income countries decreased from 2.5 million affected individuals in 2000 to 1.2 million in 2010. Of those, 584 000 were blind in 2000, in comparison with 170 000 who were blind in 2010. CONCLUSIONS: Despite the increase in the European older population, our study indicated that the number of visually impaired people has decreased in European high-income countries in the last 20 years. This may be the result of major improvements in eye care and prevention, the decreasing prevalence of eye diseases, or both.

Refractive, corneal and ocular residual astigmatism: distribution in a German population and age-dependency - the Gutenberg health study.

PURPOSE: Worldwide, the most frequent cause of visual impairment is uncorrected refractive error. This analysis focused on the distribution and associations of refractive, corneal and ocular residual astigmatism. METHODS: As part of the Gutenberg Health study, a population-based cross-sectional study was conducted in the general population of Germany. A comprehensive ophthalmological examination including refraction, tonometry, and Scheimpflug imaging of the anterior cornea (Pachycam) was performed. In addition to the magnitude and type (with-the-rule, against-the-rule, oblique) of the refractive or corneal astigmatism, we calculated the vector components (J0, J45) of both astigmatisms and calculated the ocular residual astigmatism. We performed multiple quantile regression analysis to evaluate the factors associated with refractive, corneal and ocular residual astigmatisms. RESULTS: A total of 13,558 subjects (49% female) with a mean age of 54.0 years (range 35-74 years) were included in this study. The prevalence of refractive astigmatism (>1.0D) was 13.0% in right eyes and 12.0% in left eyes, and 85% of these subjects wore spectacles. The distribution of refractive astigmatism showed a two-peak distribution with high astigmatism for with-the-rule and against-the-rule astigmatism. The associated factors were corneal curvature, age and sex for the different astigmatisms (p < 0.001). CONCLUSIONS: We analyzed the prevalence of different astigmatisms within a European population. We confirmed a shift with aging from with-the-rule to against-the-rule astigmatism to refractive and corneal astigmatism. Astigmatism has a large impact on visual perception; more than 85% of people with astigmatism over one diopter wore glasses for distance vision.

Retinal vessel metrics: normative data and their use in systemic hypertension: results from the Gutenberg Health Study.

PURPOSE OF REVIEW: In-vivo measurement of retinal vascular calibers may be used as a tool to study the pathophysiology and clinical status of the microvasculature of the retina. The aim of this study was to generate normative data for retinal vessel parameters, and to evaluate the clinical relevance in systemic hypertension. METHODS: Fundus photographs from 4309 participants of the Gutenberg Health Study were assessed using the 'retinal vessel analyzer' software (IMEDOS). We generated age and sex-specific nomograms in a disease-free subpopulation of 890 participants for determining the central retinal arteriolar equivalent (CRAE), the central retinal venular equivalent, and the arteriovenous ratio (AVR). RESULTS: Women had higher values of CRAE, central retinal venular equivalent, and AVR than men, and the decrease in measures with increasing age was less steep in women than in men. Systemic hypertension was associated with lower values [odds ratio (OR), 95% confidence interval (CI) referring to area below the 5% percentile] of AVR (men: OR 2.41, 95% CI 1.669-3.490, P < 0.001; women: OR 3.01, 95% CI 2.126-4.268, P < 0.001) and CRAE (men: OR 2.60, 95% CI 1.563-4.326, P < 0.001, women: OR 3.00, 95% CI 2.004-4.487, P < 0.001). Both median CRAE and AVR were lower in participants with uncontrolled hypertension (172.28, range 83.05-251.04; and 0.81, range 0.56-1.04) versus those with screening-detected hypertension (175.72, range 101.23-222.09, P < 0.001; and 0.82, range 0.64-1.05, P = 0.001), and versus those with controlled (179.10, range 108.19-221.92, P < 0.001; and 0.84, range 0.60-1.08, P < 0.001) hypertension. CONCLUSION: The study provides sex and age-specific normative data for retinal vasculature. Persons with untreated or insufficiently treated hypertension are more likely to have retinal vessel equivalents outside the reference range.

The Prevalence of Glaucoma in Young People.

BACKGROUND: Earlier information on the prevalence of glaucoma among children in Germany was based solely on estimates. Reported values for congenital glaucoma range from 1 in 10 000 to 1 in 68 000 depending on ethnic origin. The estimate for juvenile glaucoma is 1 in 44 000. METHODS: The Gutenberg Health Study is a populationbased, prospective, monocentric cohort study with 15 010 participants aged 35 to 74. To determine the history-based prevalence of childhood glaucoma, participants were asked about the diagnosis of glaucoma, any operations for glaucoma that were performed, regular use of drugs for glaucoma, and the age of onset of glaucoma. The affected individuals were classified in four groups based on the age of onset: congenital (<2 years), juvenile (2 to <18 years), late juvenile (18 to <40 years), and early adult (40 to <45 years). In the identified glaucoma patients, the visual acuity, intraocular pressure, corneal thickness, visual fields, and optic discs were evaluated. RESULTS: 352 persons were identified from their medical history as having glaucoma. The weighted prevalences in the four groups were 0% in the congenital group, 0.01% (95% confidence interval [0, 0.03]) in the juvenile group, 0.16 % ([0.09; 0.23]) in the late juvenile group, and 0.17% ([0.15; 0.19]) in the early adult group. For participants over age 45, the weighted prevalence of glaucoma was 1.98% [1.7; 2.2]. CONCLUSION: In our cohort, the history-based prevalence of juvenile glaucoma was 0.01% (2 patients). The prevalence was an order of magnitude higher (0.16%) between the ages of 18 and 40, and two orders of magnitude higher at later ages (1.98%). The burden of disease seems to be markedly higher than previously assumed.

Cardiovascular medication and intraocular pressure: results from the Gutenberg Health Study.

BACKGROUND: Intraocular pressure (IOP) is well known to be associated with blood pressure and other cardiovascular risk factors. The influence of systemic cardiovascular, in particular antihypertensive, medication on IOP is still controversial. This study analyses the association between the use of cardiovascular medications and IOP in a large European cohort. METHODS: The Gutenberg Health Study is a population-based, prospective,observational cohort study in mid-western Germany. IOP was measured using a non-contact tonometer. The medication classes examined were peripheral vasodilators, diuretics, ß-blockers (overall, selective and non-selective), calcium channel blockers, renin-angiotensin blockers (overall, ACE inhibitors and angiotensin-receptor blockers), nitrates, other antihypertensive medications, aspirin and statins. Subjects with missing IOP values, topical IOP-lowering medication or previous ocular surgery were excluded. In total, 13 527 subjects were enrolled in this study. Association analyses between medication use and IOP were performed using multivariable linear regression (p<0.0038). RESULTS: Neither selective nor non-selective systemic ß-blocker intake was associated with statistically significant lower IOP (-0.12 mm Hg, p=0.054 and -0.70 mm Hg, p=0.037, respectively). IOP was not associated with the use of ACE inhibitors after adjustment for body mass index, systolic blood pressure and central corneal thickness (0.11 mm Hg; p=0.07). CONCLUSIONS: None of the cardiovascular medications, in particular systemic ß-blocking agents, showed an association with IOP in non-glaucoma subjects. The long-term drift phenomenon of topical and systemic ß-blocker might explain this result. Our results suggest that systemic ß-blockers have a negligible effect on IOP reduction.

Myopia and Cognitive Performance: Results From the Gutenberg Health Study.

PURPOSE: To analyze the association between myopia and cognitive performance. METHODS: A cohort of the population-based Gutenberg Health Study included 3819 eligible enrollees between 40 and 79 years. We used the Tower of London (TOL) test to assess cognitive performance. Myopia was defined as a spherical equivalent (SE) ≤ -0.5 diopters (D) via noncycloplegic autorefractometry. We conducted linear mixed models with the SE as the dependent variable and the age, sex, duration of education, and TOL score as covariates. RESULTS: Complete data were available for 3452 participants (90.4%). The mean TOL score was 14.0 ± 3.9 in the myopes versus 12.9 ± 4.0 in the nonmyopes (P < 0.001). The mean TOL score increased with the magnitude of myopia: it was 13.9 ± 3.9 in low (less than -3 D); 14.2 ± 3.7 in moderate (between -3 and -6 D); and 14.6 ± 3.5 in high myopia (-6 D and greater; P < 0.001). Both the duration of education and cognitive performance were correlated with the magnitude of myopia (r = -0.21, P < 0.001 and r = -0.15, P < 0.001, respectively). In a linear mixed model, the duration of education significantly predicted myopia (ß = -0.14; t = -7.55; P < 0.001), whereas cognitive performance did not (ß = -0.017; t = -1.26; P = 0.207). There was a significant effect of age on the SE (ß = 0.049; t = 9.89; P < 0.001). CONCLUSIONS: When regarded separately, cognitive performance is linked to myopia. However, duration of education, which may be directly related to the risk factors for myopia, is more directly and strongly related to myopia than is cognitive performance. Cognitive ability may be associated with myopia primarily through its impact on level of education.