Bi-Gaussian analysis reveals distinct education-related alterations in spherical equivalent and axial length-results from the Gutenberg Health Study.

PURPOSE: The aim of this study is to investigate the distribution of spherical equivalent and axial length in the general population and to analyze the influence of education on spherical equivalent with a focus on ocular biometric parameters. METHODS: The Gutenberg Health Study is a population-based cohort study in Mainz, Germany. Participants underwent comprehensive ophthalmologic examinations as part of the 5-year follow-up examination in 2012-2017 including genotyping. The spherical equivalent and axial length distributions were modeled with gaussian mixture models. Regression analysis (on person-individual level) was performed to analyze associations between biometric parameters and educational factors. Mendelian randomization analysis explored the causal effect between spherical equivalent, axial length, and education. Additionally, effect mediation analysis examined the link between spherical equivalent and education. RESULTS: A total of 8532 study participants were included (median age: 57 years, 49% female). The distribution of spherical equivalent and axial length follows a bi-Gaussian function, partially explained by the length of education (i.e., < 11 years education vs. 11-20 years). Mendelian randomization indicated an effect of education on refractive error using a genetic risk score of education as an instrument variable (- 0.35 diopters per SD increase in the instrument, 95% CI, - 0.64-0.05, p = 0.02) and an effect of education on axial length (0.63 mm per SD increase in the instrument, 95% CI, 0.22-1.04, p = 0.003). Spherical equivalent, axial length and anterior chamber depth were associated with length of education in regression analyses. Mediation analysis revealed that the association between spherical equivalent and education is mainly driven (70%) by alteration in axial length. CONCLUSIONS: The distribution of axial length and spherical equivalent is represented by subgroups of the population (bi-Gaussian). This distribution can be partially explained by length of education. The impact of education on spherical equivalent is mainly driven by alteration in axial length.

Much higher prevalence of keratoconus than announced results of the Gutenberg Health Study (GHS).

Keratoconus appears to be a rare corneal disease with a prevalence previously estimated at 1:2000. The aim of our study was to investigate the prevalence of keratoconus in a large German cohort and to evaluate possible associated factors. METHOD: In the population-based, prospective, monocentric cohort study, Gutenberg Health Study, 12,423 subjects aged 40-80 years were examined at the 5-year follow-up. Subjects underwent a detailed medical history and a general and ophthalmologic examination including Scheimpflug imaging. Keratoconus diagnosis was performed in two steps: all subjects with conspicuous TKC analysis of corneal tomography were included in further grading. Prevalence and 95% confidence intervals were calculated. Logistic regression analysis was carried out to investigate association with age, sex, BMI, thyroid hormone, smoking, diabetes, arterial hypertension, atopy, allergy, steroid use, sleep apnea, asthma, and depression. RESULTS: Of 10,419 subjects, 75 eyes of 51 subjects were classified as having keratoconus. The prevalence for keratoconus in the German cohort was 0.49% (1:204; 95% CI: 0.36-0.64%) and was approximately equally distributed across the age decades. No gender predisposition could be demonstrated. Logistic regression showed no association between keratoconus and age, sex, BMI, thyroid hormone, smoking, diabetes, arterial hypertension, atopy, allergy, steroid use, sleep apnea, asthma, and depression in our sample. CONCLUSION: The prevalence of keratoconus disease in a mainly Caucasian population is approximately tenfold higher than previously reported in the literature using latest technologies (Scheimpflug imaging). Contrary to previous assumptions, we did not find associations with sex, existing atopy, thyroid dysfunction, diabetes, smoking, and depression.

Ocular geometry in adults born extremely, very and moderately preterm with and without retinopathy of prematurity: results from the Gutenberg Prematurity Eye Study.

BACKGROUND/AIMS: To evaluate whether anterior segment anatomy and axial length are associated with prematurity and perinatal factors in adults. METHODS: The Gutenberg Prematurity Eye Study examined adults born preterm and term aged 18-52 years. All participants underwent a prospective ophthalmic examination (optical biometry via a LenStar 900, Haag-Streit) in Germany. The associations between gestational age (GA), birth weight (BW) and BW percentile, retinopathy of prematurity (ROP) occurrence, ROP treatment and other perinatal factors with the main outcome measures were evaluated by univariate and multivariable linear regression analyses. Main outcome measures were corneal radius, white-to-white distance, anterior chamber depth, lens thickness and axial length. RESULTS: The study involved 861 eyes of 438 preterm and full-term individuals (aged 28.6±8.7 years, 245 females,). After adjustment for age and gender, a steeper corneal radius was associated with lower GA (B=0.02; p<0.001) and a lower BW percentile (B=0.003; p<0.001). A smaller white-to-white distance was linked to lower GA (B=0.02; p<0.001), a lower BW percentile (B=0.004; p<0.001) and postnatal ROP occurrence (B=-0.26; p<0.001). Decreased axial length was associated with lower GA at birth (B=0.05; p=0.002) and pre-eclampsia (B=-0.34; p=0.015). ROP-treated eyes had a shallower anterior chamber depth (B=-0.63; p=0.001) and increased lens thickness (B=0.64, p<0.001). CONCLUSION: Our analyses in adults demonstrate that the corneal morphology is influenced by GA and BW percentile, while the anterior chamber depth and lens thickness are affected by ROP treatment, namely laser therapy and cryotherapy. The present study highlights that perinatal factors lead to lifelong sequelae of ocular shape.

Twenty-Years of Experience in Childhood Glaucoma Surgery.

To quantify the results of childhood glaucoma treatment over time in a cohort of children with different types of childhood glaucoma. A retrospective cohort study of consecutive cases involving children with primary congenital glaucoma, primary juvenile, and secondary juvenile glaucoma at the Childhood Glaucoma Center, University Medical Center Mainz, Germany from 1995 to 2015 was conducted. The main outcome measure was the long-term development of intraocular pressure. Further parameters such as surgical success, refraction, corneal diameter, axial length, and surgical procedure in children with different types of childhood glaucoma were evaluated. Surgical success was defined as IOP < 21 mmHg in eyes without a need for further intervention for pressure reduction. A total of 93 glaucomatous eyes of 61 childhood glaucoma patients with a mean age of 3.7 ± 5.1 years were included. The overall mean intraocular pressure at first visit was 32.8 ± 10.2 mmHg and decreased to 15.5 ± 7.3 mmHg at the last visit. In the median follow-up time of 78.2 months, 271 surgical interventions were performed (130 of these were cyclophotocoagulations). Many (61.9%) of the eyes that underwent surgery achieved complete surgical success without additional medication. Qualified surgical success (with or without additional medication) was reached by 84.5% of the eyes.

Peripapillary Retinal Nerve Fiber Layer Profile in Relation to Refractive Error and Axial Length: Results From the Gutenberg Health Study.

Purpose: To investigate the retinal nerve fiber layer profile measured by optical coherence tomography and its relation to refractive error and axial length. Methods: The Gutenberg Health Study is a population-based study in Mainz, Germany. At the five-year follow-up examination, participants underwent optical coherence tomography, objective refraction and biometry. Peripapillary retinal nerve fiber layer (pRNFL) was segmented using proprietary software. The pRNFL profiles were compared between different refraction groups and the angle between the maxima, i.e., the peaks of pRNFL thickness in the upper and lower hemisphere (angle between the maxima of pRNFL thickness [AMR]) was computed. Multivariable linear regression analysis was carried out to determine associations of pRNFL profile (AMR) including age, sex, optic disc size, and axial length in model 1 and spherical equivalent in model 2. Results: A total of 5387 participants were included. AMR was 145.3° ± 23.4° in right eyes and 151.8° ± 26.7° in left eyes and the pRNFL profile was significant different in the upper hemisphere. The AMR decreased with increasing axial length by -5.86°/mm (95% confidence interval [CI]: [-6.44; -5.29], P < 0.001), female sex (-7.61°; 95% CI: [-8.71; -6.51], P < 0.001) and increased with higher age (0.08°/year; 95% CI: [0.03; 0.14], P = 0.002) and larger optic disc size (2.29°/mm2; 95% CI: [1.18; 3.41], P < 0.001). In phakic eyes, AMR increased with hyperopic refractive error by 2.60°/diopters (dpt) (95% CI: [2.33; 2.88], P < 0.001). Conclusions: The pRNFL profiles are related to individual ocular and systemic parameters. Translational Relevance: Biometric parameters should be considered when pRNFL profiles are interpreted in diagnostics, i.e., in glaucoma.

Efficacy and safety of XEN®-Implantation vs. trabeculectomy: Data of a "real-world" setting.

OBJECTIVE: To compare surgical success, postoperative intraocular pressure and complication rates between trabeculectomy and XEN gelstent surgery in a cohort of glaucoma patients in a typical clinical setting. METHODS: A retrospective cohort study of consecutive patients with refractory open-angle glaucoma including patients who underwent either stand-alone XEN gelstent insertion with Mitomycin C or trabeculectomy with Mitomycin C between 2016 and 2018 at the University Eye Hospital Mainz, Germany. Primary outcome measure was the proportion of surgical success 1 year after surgery. Patients with an IOP ≤18mmHg, an intraocular pressure reduction of >20% and in no need of revision surgery or topical medication were considered a complete surgical success. If topical therapy was necessary, they were considered a qualified success. Multivariable logistic regression analysis was carried out for the primary outcome including gender, age, preoperative intraocular pressure and number of medication classes used preoperatively as adjustment variables. RESULTS: 171 eyes of 144 patients were included, including 82 eyes of 58 patients in the XEN group and 89 eyes of 86 patients in the trabeculectomy group. The primary outcome defined as the proportion of surgical success after 1 year (mean 11.1 months ± 2.2) was similar for both groups. The complete success proportion was 65.5% (95%-CI: 55.6-75.9%) in the trabeculectomy group, and 58.5% (95%-CI: 47.6-69.4%) in the XEN group and not statistically different in our analysis model (crude OR = 0.61; 95%-CI: 0.31-1.22; adjusted OR = 0.66; 95%-CI: 0.32-1.37). The intraocular pressure reduction, as secondary outcome measure, was higher in the trabeculectomy group (10.5 mmHg) compared to the XEN group (7.2 mmHg; p = 0.003) at the 12-month follow-up. CONCLUSION: Both XEN gelstent implantation and trabeculectomy show similar proportions of surgical success and of complications and are therefore both recommendable for clinical routine. However, trabeculectomy seems to be more effective in lowering intraocular pressure than the XEN implantation. A prospective randomized clinical trial is necessary to evaluate differences in the long-term clinical outcome.

Characteristics and pathologies of the vitreo-macular interface-results from the Gutenberg Health Study.

PURPOSE: We aimed to determine the prevalence of characteristics and pathologies of the vitreo-macular interface within the general population. METHODS: The Gutenberg Health Study is a population-based study in Germany, including an ophthalmological examination with refraction, biometry and optical coherence tomography (OCT) imaging. Characteristics of the vitreo-macular interface were graded on volume scans including visibility of an epiretinal membrane, full-thickness macular hole, lamellar hole and pseudohole. Overall and age-specific prevalences including 95% confidence intervals [95%-CI] were calculated. Association analyses were conducted to determine systemic and ocular factors that are associated with epiretinal membranes (the most common pathology) using multivariable logistic regression. RESULTS: A total of 1890 people aged 40-80 years were included in the study. Of these, 4.7% (95%-CI: 3.8%-5.8%) had an epiretinal membrane in at least one eye, 0.1% a full-thickness macular hole, 0.6% a lamellar hole and 0.6% a pseudohole. The presence of an epiretinal membrane was associated with higher age, myopic refractive error and prior retinal laser therapy, but not with gender, body height, body weight, smoking, prior cataract surgery or intraocular pressure. CONCLUSIONS: Epiretinal membranes are more frequent in older and myopic subjects and in those with prior retinal laser therapy.

Associations of cardiovascular risk factors and retinal vessel dimensions at present and their evolution over time in a healthy working population.

PURPOSE: The aim of this study was to investigate whether an association between retinal vessel diameters with blood pressure and other risk factors exists in a healthy working population and whether current risk factors can be used as predictors for retinal vessel changes over time. METHODS: Retinal photographs and medical data were obtained during a voluntary work health check in 2010 and 2013. The central retinal arterial equivalent (CRAE) and central retinal venular equivalent (CRVE) were assessed using a semi-automated software. Linear regression analysis was carried out to determine associations with systemic parameters and cardiovascular risk factors. RESULTS: A total of 1685 participants had gradable photographs and full medical data with a mean age of 44.8 years (SD: 10.2) and 80.8% being male; full data were obtained in both 2010 and 2013 for 365 participants allowing for longitudinal analysis. In the cross-sectional analysis, a mean CRAE of 171.2 ±18.3 µm and a mean CRVE 215.8 ± 18.6 µm were found. A significant negative association for CRAE was seen for age, mean arterial blood pressure (MABP), body mass index (BMI) and high-density lipoprotein (HDL), while triglycerides, spherical equivalent (SAE) and being a current smoker were positively associated. For CRVE age, MABP, HbA1c and HDL were negatively associated, while being female, low-density lipoprotein, white blood cell count, SAE and being a current smoker showed a positive association. The linear regression model for the cross-sectional analysis explained 31% and 21% of the variance of CRAE and CRVE, respectively. The longitudinal analysis showed a mean decrease of -1.6 µm (p = 0.04) for CRAE and -2.0 (p = 0.005) for CRVE within the three-year time frame. Linear regression analysis with longitudinal data showed a significant association for HDL and CRAE, while for other factors no statistically significant association between current risk factors and changes in CRAE and CRVE was observed. CONCLUSION: The width of both arterial and venous retinal vessels shows associations not only with arterial blood pressure but also with biochemical markers of cardiovascular risk. While such effects are partially established for elderly persons, our study results indicate that they apply also in a young population in working age with seemingly unimpaired health.

Optical Coherence Tomography Angiography of Optic Disc in Eyes With Primary Open-angle Glaucoma and Normal-tension Glaucoma.

PURPOSE: To examine vessel density (VD) properties of the optic nerve head in eyes with ocular hypertension (OHT), high-tension glaucoma (HTG), and normal-tension glaucoma (NTG) and to evaluate associations on structural parameters of retinal nerve fiber layer (RNFL). METHODS: Three groups of patients with OHT (n=15), HTG (n=36), and NTG (n=22), and a healthy control group (n=23) were included in this study. Peripapillary VD and optic disc flow area were measured using optical coherence tomography angiography, and peripapillary RNFL (pRNFL) thickness was determined. Global and sectoral analysis of optic nerve head vasculature and pRNFL thickness were measured. RESULTS: Glaucomatous eyes had lower global peripapillary VD (HTG: 54.04±5.11, NTG: 54.74±6.37) compared with nonglaucomatous eyes (OHT: 59.72±1.63, controls: 61.35±2.47). VD parameters of the optic disc were comparable between the control and OHT group and between the HTG and NTG group. In the HTG and NTG groups we found significant correlations between average peripapillary VD and global pRNFL thickness (HTG ρ=0.71, P<0.001; NTG ρ=0.65, P=0.001). This was true for all sectors except for the temporal position. CONCLUSIONS: Overall, glaucomatous eyes had lower peripapillary VD compared with normal and OHT eyes. There is a strong relationship between the peripapillary structure of RNFL and its vasculature.

Association of low birth weight with myopic refractive error and lower visual acuity in adulthood: results from the population-based Gutenberg Health Study (GHS).

PURPOSE: Low birth weight (BW) is linked to impaired organ development in childhood, including altered ocular morphological and functional development. The aim of this study was to evaluate whether low BW has long-term effects on visual acuity and refraction in adulthood. METHODS: The Gutenberg Health Study is a population-based, observational cohort study in Germany, including 15 010 participants aged between 35 and 74 years. These participants were divided into three different BW groups (low: <2500 g; normal: between 2500 and 4000 g; and high: >4000 g). Best-corrected visual acuity and objective refraction were examined. We used multivariable linear regression models with adjustment for age, sex, socioeconomic status and self-reported glaucoma, age-related macular degeneration, corneal disease and cataract to assess associations between BW and the main outcome measures, best-corrected visual acuity, spherical equivalent and astigmatism. RESULTS: Overall, 8369 participants reported their BW. In a multivariable analysis, an association for low BW with spherical equivalent (B=-0.28 per dioptre, P=0.005) and best-corrected visual acuity (B=0.02 logarithm of the minimum angle of resolution, P=0.006) compared with normal BW was observed. For participants with high BW, an association was observed with spherical equivalent (B=0.29 per dioptre, P<0.001), while none with visual acuity. CONCLUSIONS: Our data demonstrated that low BW is linked to visual acuity and refractive long-term outcomes long after childhood. Individuals with low BW are more likely to have lower visual acuity and a higher myopic refractive error in adulthood. Adults with high BW are more likely to have a more hyperopic refractive error.

Eye Pain and Dry Eye in Patients with Fibromyalgia.

Objectives: The aim of this study was to examine visual function and eye symptoms in fibromyalgia patients, with a particular focus on dry eye syndrome and eye pain. Methods: A tertiary care center-based cross-sectional study was carried out in chronic musculoskeletal pain patients diagnosed with fibromyalgia. Chronic musculoskeletal pain patients without fibromyalgia were enrolled as a comparison group. Self-reported eye pain was investigated with the McGill pain questionnaire and the numeric rating scale. In addition, we assessed corrected visual acuity, vision-related quality of life, and self-reported dry eye syndrome. Results: A total of 90 musculoskeletal pain patients were included, with 66 patients fulfilling American College of Rheumatology 1990 criteria for fibromyalgia. Sixty-seven percent (95% confidence interval [CI] = 56%-78%) of the fibromyalgia patients reported eye pain, and 62% (95% CI = 43%-81%) of those were without fibromyalgia diagnosis. Sixty-seven percent (95% CI = 56%-78%) of the fibromyalgia patients reported an experience of dry eye compared with 76% (95% CI = 57%-95%) in the nonfibromyalgia group. Vision-related quality of life was noticeably reduced in both groups. Conclusions: Eye pain and dry eye are common in chronic pain patients, with comparable prevalence in musculoskeletal pain patients with and without fibromyalgia.

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.

Determinants of peripapillary retinal nerve fiber layer thickness regarding ocular and systemic parameters - the MIPH Eye&Health Study.

BACKGROUND: Optical coherence tomography (OCT) allows quantitative image analysis of retinal tissue in vivo. Peripapillary retinal nerve fiber layer (pRNFL) thickness is widely used for evaluation of retinal nerve fiber rarefaction in several optic neuropathies. This study evaluates associations of pRNFL thickness in healthy adult subjects in order to evaluate influencing factors. METHODS: A cross-sectional study was performed in a working-age population. Only eyes without detectable ocular pathologies were included in the analysis. Among analyzed systemic cardiovascular parameters were age, gender, body-mass index, mean arterial blood pressure, HbA1c, high- and low-density-lipoproteins, and triglycerides. A comprehensive ophthalmological examination including refraction, tonometry, keratometry, and central corneal thickness measurmentwas performed. In addition, pRNFL thickness was imaged by spectral-domain OCT. Univariable and multivariable associations of pRNFL thickness in all four quadrants and on average with systemic and ocular parameters were calculated using a generalized estimating equation model. RESULTS: Three hundred and six subjects were included. pRNFL thickness measurements showed a significant association with spherical equivalent: pRNFL thickness decreased with increasing myopia in all quadrants (multivariable regression coefficients Beta: superior: 1.16, 95 % CI [0.62;1.71], p < 0.001; temporal: 0.87, [0.33;1.41], p = 0.001; inferior: 1.80, [1.18;2.42], p < 0.001; nasal: 2.60, [2.01;3.20], p < 0.001) and on average (1.51, [1.20;1.82], p < 0.001). A thicker central cornea thickness was related to lower pRNFL in the superior (-0.05, [-0.10; -0.01], p = 0.01), the inferior quadrant (-0.05, [-0.10;0.00], p = 0.03) and on average (-0.04, [-0.07; -0.01], p = 0.02). All other parameters were not  associated. CONCLUSION: Our findings highlight the importance of refraction when evaluating pRNFL thickness and its independence from other systemic parameters.

Central Corneal Thickness in Spectral-Domain OCT and Associations with Ocular and Systemic Parameters.

Background. Optical coherence tomography (OCT) allows quantitative analysis of the anterior segment of the eye with a noncontact examination. The aim of this study is to analyze associations of central corneal thickness (CCT) as measured by OCT with ocular and systemic cardiovascular parameters. Methods. A cross-sectional study of 734 persons was performed in a working age population. Only healthy eyes were included. A comprehensive ophthalmological examination including refraction, noncontact tonometry, and imaging of the anterior segment by SD-OCT was performed. In parallel, a broad range of systemic cardiovascular parameters were measured. Associations were analyzed using a generalized estimating equations' model. Results. CCT measurements showed a significant association with corneal curvature and intraocular pressure: a thinner CCT was associated with a flatter cornea and with lower intraocular pressure (p < 0.001). Age was positively associated with CCT (p < 0.001); all other cardiovascular parameters were not associated. Conclusion. A thinner cornea is associated with a flatter surface and with lower intraocular pressure readings, while there are no independent associations with refraction and systemic cardiovascular parameters. Our findings highlight the value of SD-OCT CCT measurements as a standard tool in anterior segment analysis.

Associations of macular thickness in spectral-domain OCT with ocular and systemic cardiovascular parameters - the MIPH Eye & Health Study.

PURPOSE: Beyond in-vivo histological analysis of retinal tissue, optical coherence tomography (OCT) allows quantitative image analysis. This study evaluates associations of macular retinal thickness measured with spectral-domain OCT (SD-OCT) and ocular and systemic cardiovascular parameters in adult subjects. METHODS: An epidemiological cross-sectional study was performed in the staff of a European high-tech company. Examination of known cardiovascular risk factors including biochemical blood analysis was performed, and ocular parameters such as refraction, tonometry, SD-OCT imaging of the macula and cornea, and fundus photography were evaluated. Retinal thickness measurements were evaluated according to the ETDRS grid. Associations of macular retinal thickness and systemic cardiovascular and ocular parameters were calculated by multivariate analysis using SPSS software. RESULTS: Four hundred and twenty-four probands were included. Macular thickness measurement were significantly associated with gender and refraction. Female persons had thinner retinal thickness in all zones. Macular thickness decreased with increasing myopia in all perifoveal measurements. Outer perifoveal measurements were associated with keratometry; a flatter corneal radius was linked to a thinner retina. Tonometry and systemic cardiovascular risk factors were not associated with macular retinal thickness in multivariate analysis (p > 0.05). CONCLUSIONS: Macular retinal thickness is associated with refraction and gender; cardiovascular risk factors or tonometry do not influence macular retinal thickness measurements. Keratometry might influence outer zone measurements. Our findings provide a dataset for quantitative evaluation of SD-OCT, and evaluate influencing factors.

A retinal snap shot may indicate individual risk for cardiovascular disease - the MIPH Eye&Health Study.

BACKGROUND: Examination of retinal vasculature can be used to non-invasively quantify changes within the microvasculature of the human body and might be a predictor of cardiovascular disease. This study evaluates associations of the structure of the retinal vasculature with established risk factors for cardiovascular disease. METHODS: A cross-sectional study was performed in a working age population. Several systemic cardiovascular parameters were analyzed and PROCAM- and SCORE-risk estimates were calculated. A quantitative ophthalmological examination including digital fundus imaging has taken place. Central retinal arterial/venous equivalents (CRAE/CRVE) and arterio-venous ratio (AVR) were analyzed using validated software. Associations of retinal vessel parameters and systemic cardiovascular and ocular parameters were calculated by multivariate analysis using SPSS software. A p-value of <0.05 with Bonferroni correction was accepted as significant. RESULTS: 338 probands were included. A smaller CRAE was independently associated with increased mean arterial blood pressure, higher age and higher body-mass index. Regarding CRVE age was inversely associated. Other cardiovascular risk parameters were not associated to the examined retinal vessel equivalents. AVR showed a significant association to mean arterial blood pressure and body-mass-index. PROCAM- and SCORE-risk estimates were negatively associated with CRAE and AVR, but not associated to CRVE. CONCLUSIONS: Arterial retinal vessel analysis and AV-ratio showed associations to established cardiovascular parameters in the study population. PROCAM- and SCORE-risk estimates as indicators of cardiovascular risk were associated with the CRAE and the AV-ratio. This suggests that a single snap shot of the retinal vessels may indicate the individual relative risk for cardiovascular events.

Optical coherence tomography-based retinal vessel analysis for the evaluation of hypertensive vasculopathy.

PURPOSE: Evaluation of retinal vessels in cardiovascular disease traditionally relies upon funduscopy, but more recently digital photo analysis has expanded the spectrum. As spectral domain optical coherence tomography (OCT) allows an in-vivo assessment of retinal tissue and its vessels on a histological scale, our study aimed at using this tool for the analysis of the retinal vasculature. METHODS: Circumferential peripapillary OCT scans (3DOCT-2000; Topcon Inc., Tokyo, Japan), with centration on the optic nerve head, were taken from 20 eyes (20 participants) with normal blood pressure and 20 eyes (20 participants) with arterial hypertension above 120 mmHg (mean blood pressure). The diameter of all vessels intersecting the scan line was measured in the OCT and used to calculate central vessel equivalents, and the A/V ratios were calculated. Bland-Altman analysis was performed to evaluate reliability. Correlation coefficients were determined for reliability of the method as well as with the individual mean arterial blood pressures. RESULTS: Forty eyes (40 participants) were included in the study. Mean arterial blood pressure was 96±4 mmHg in the control group and 132±7 mmHg in the hypertonic group. Mean A/V ratio as determined from OCT scans was 0.82±0.13 (normotonic) versus 0.62±0.11 (hypertonic). A Pearson's correlation coefficient of 0.67 (p<0.001) was determined between A/V ratio and blood pressure. CONCLUSIONS: Our results highlight the feasibility of retinal vessel measurements in spectral domain OCT. A relation between mean arterial blood pressure and OCT-based A/V ratio was established. Further research will elucidate influencing factors and provide a broader basis for therapeutic approaches.

Semi-automated retinal vessel analysis in nonmydriatic fundus photography.

PURPOSE: Funduscopic assessment of the retinal vessels may be used to assess the health status of microcirculation and as a component in the evaluation of cardiovascular risk factors. Typically, the evaluation is restricted to morphological appreciation without strict quantification. Our purpose was to develop and validate a software tool for semi-automated quantitative analysis of retinal vasculature in nonmydriatic fundus photography. METHODS: matlab software was used to develop a semi-automated image recognition and analysis tool for the determination of the arterial-venous (A/V) ratio in the central vessel equivalent on 45° digital fundus photographs. Validity and reproducibility of the results were ascertained using nonmydriatic photographs of 50 eyes from 25 subjects recorded from a 3DOCT device (Topcon Corp.). Two hundred and thirty-three eyes of 121 healthy subjects were evaluated to define normative values. RESULTS: A software tool was developed using image thresholds for vessel recognition and vessel width calculation in a semi-automated three-step procedure: vessel recognition on the photograph and artery/vein designation, width measurement and calculation of central retinal vessel equivalents. Mean vessel recognition rate was 78%, vessel class designation rate 75% and reproducibility between 0.78 and 0.91. Mean A/V ratio was 0.84. Application on a healthy norm cohort showed high congruence with prior published manual methods. Processing time per image was one minute. CONCLUSIONS: Quantitative geometrical assessment of the retinal vasculature may be performed in a semi-automated manner using dedicated software tools. Yielding reproducible numerical data within a short time leap, this may contribute additional value to mere morphological estimates in the clinical evaluation of fundus photographs.