Light-Modulated Sunscreen Mechanism in the Retina of the Human Eye.

The functioning of the human eye in the extreme range of light intensity requires a combination of the high sensitivity of photoreceptors with their photostability. Here, we identify a regulatory mechanism based on dynamic modulation of light absorption by xanthophylls in the retina, realized by reorientation of pigment molecules induced by trans-cis photoisomerization. We explore this photochemically switchable system using chromatographic analysis coupled with microimaging based on fluorescence lifetime and Raman scattering, showing it at work in both isolated human retina and model lipid membranes. The molecular mechanism underlying xanthophyll reorientation is explained in terms of hydrophobic mismatch using molecular dynamics simulations. Overall, we show that xanthophylls in the human retina act as "molecular blinds", opening and closing on a submillisecond timescale to dynamically control the intensity of light reaching the photoreceptors, thus enabling vision at a very low light intensity and protecting the retina from photodegradation when suddenly exposed to strong light.

Quantification of the Visual Field Loss in Retinitis Pigmentosa Using Semi-Automated Kinetic Perimetry.

PURPOSE: To assess quantitatively the natural course of the visual field (VF) loss in patients with retinitis pigmentosa (RP) during 2-year period of observation. METHODS: VFs were obtained by semi-automated kinetic perimetry (SKP) during four examinations of 16 patients suffering from RP. Three stimulus conditions (V4e, III4e and I4e) with a constant stimulus angular velocity of 3°/s were used to assess the hill of vision in both eyes of each patient. The area of each isopter was measured in square degrees and corrected for the individual reaction time (RT). RESULTS: There were four patients with mild restriction of VF, six with ring scotomas and six with advanced concentric constrictions of VF. Only I4e isopter area decreased significantly from the first to the last session (p = 0.006), the difference was 154 deg(2) being 13% of initial isopter area. The difference was not significant for V4e and III4e isopters. RT values did not differ significantly between four sessions. CONCLUSIONS: Only I4e isopter's area was decreased significantly during two years of observation. SKP provides a method of assessment of progression of the VF loss in patients suffering from RP by measurement of the isopters' area over time.

Confocal Laser Scanning Tomography to Predict Visual Field Conversion in Patients With Ocular Hypertension and Early Glaucoma.

PURPOSE: To compare Moorfields regression analysis (MRA), Glaucoma probability score (GPS), and different discriminant functions to predict future visual field conversion of patients with ocular hypertension and early glaucoma. PATIENTS AND METHODS: The study included 120 eyes of patients with ocular hypertension and 110 eyes of patients with early glaucoma from the Erlangen glaucoma registry. Annually, all patients underwent standard automated perimetry, 24-hour intraocular pressure profile, optic disc photography, and HRT (Heidelberg Retina Tomograph I-III; Heidelberg Engineering) measurements. The cohort was divided into 2 groups based on the development of repeatable glaucomatous visual fields. Positive predictive values and negative predictive values were compared for MRA, GPS, and the classification of Bathija, Iester, Mardin, and Mikelberg at baseline. Kaplan-Meier Survival curves and Logrank tests were used to evaluate equality of survival distributions for different test results. RESULTS: Median follow-up was 9.04 years. 26 eyes (11.3%) demonstrated glaucomatous visual field loss in the follow-up. MRA temporal-superior and temporal-inferior outside normal limits were predictive of future visual field loss with positive predictive values of 33.3% and 28.6%. Normal GPS Temporal Sector demonstrated a negative predictive value of 96.4% and normal results in discriminant functions between 94.7% and 95.5%. CONCLUSIONS: Confocal scanning laser tomography is a useful imaging modality to predict future visual field conversion. Development of visual field defects in 10 years is highly unlikely, if GPS classification and/or classification of discriminant analysis at baseline are normal. MRA temporal-superior and temporal-inferior outside normal limits are associated with future VF conversion (ClinicalTrials.gov number, NCT00494923).

The Effect of Long-term Antiglaucomatous Drug Administration on Central Corneal Thickness.

PURPOSE: To evaluate rates of changes per year of central corneal thickness after antiglaucomatous drug administration with ß-blockers, prostaglandin analogs, and carbonic anhydrase inhibitors monotherapy and combined topical antiglaucomatous therapy, in a cohort of patients with ocular hypertension, glaucoma suspects, and patients with perimetric glaucoma as compared with normal controls. PATIENTS AND METHODS: This retrospective single-center study included 130 eyes as healthy controls, 121 eyes of ocular hypertensive patients, 105 eyes of glaucoma suspects, and 49 eyes of perimetric glaucoma patients. All patients underwent standard automated perimetry, 24-hour intraocular pressure profile, optic disc photography, and optical coherence pachymetry (OCP; Heidelberg Engineering). The cohort was divided into 8 groups on the basis of topical antiglaucomatous medication. Linear regression analysis was conducted to analyze the relationship between central corneal thickness and exposure to antiglaucomatous medication during the follow-up. RESULTS: Central corneal thickness did not change during the follow-up for investigated diagnostic subgroups. There was a statistically significant decrease in central corneal thickness for eyes treated with prostaglandin monotherapy (-3.1 µm/y for left eye), and a combined therapy with prostaglandins, carbonic anhydrase inhibitors, and ß-blockers (-5.8 and -3.8 µm/y for right and left eye, respectively). CONCLUSIONS: We recommend regular measurements before and during therapy with prostaglandin monotherapy and a combined therapy with prostaglandins, carbonic anhydrase inhibitors, and ß-blockers. Follow-up intraocular pressure measurements may be underestimated for eyes treated with the aforementioned treatment regimens if central corneal thickness is not measured on a regular basis.

Current treatment modalities in diabetic macular edema.

Diabetic macular edema is the major cause of vision impairment in the diabetic population. Its treatment requires a multidisciplinary approach and the use of both systemic and local therapies. Current management includes the vascular endothelial growth factor inhibitors and steroids administered as intravitreal injections, as well as laser therapy and surgical treatment. Treatment modalities in diabetic macular edema have changed in recent years, after the introduction of vascular endothelial growth factor inhibitors, which are gradually replacing laser photocoagulation. All anti-VEGF agents tested so far showed efficacy in the treatment of diabetic macular edema. Due to structural differences, the therapeutic efficacy of different anti-VEGF products varies. According to recent results, 2,0 mg of aflibercept is more effective than 0,3 mg of ranibizumab in patients with lower visual acuity at baseline. Additionally, its superiority was shown in reducing the number of required macular laser photocoagulation procedures. This article provides a comprehensive overview of available therapeutic modalities based on laser photocoagulation, anti-VEGF agents, steroid injections or surgical interventions, and discusses their efficacy in patients with diabetic macular edema.

Wide-Field Landers Temporary Keratoprosthesis in Severe Ocular Trauma: Functional and Anatomical Results after One Year.

Purpose. To evaluate longitudinal functional and anatomical results after combined pars plana vitrectomy (PPV) and penetrating keratoplasty (PKP) using a wide-field Landers intraoperative temporary keratoprosthesis (TKP) in patients with vitreoretinal pathology and corneal opacity due to severe ocular trauma. Material and Methods. Medical records of 12 patients who had undergone PPV/PKP/KP due to severe eye trauma were analyzed. Functional (best-corrected visual acuity) and anatomic outcomes (clarity of the corneal graft, retinal attachment, and intraocular pressure) were assessed during the follow-up (mean 16 months). Results. Final visual acuities varied from NLP to CF to 2 m. Visual acuity improved in 7 cases, was unchanged in 4 eyes, and worsened in 1 eye. The corneal graft was transparent during the follow-up in 3 cases and graft failure was observed in 9 eyes. Silicone oil was used as a tamponade in all cases and retina was reattached in 92% of cases. Conclusions. Combined PPV and PKP with the use of wide-field Landers TKP allowed for surgical intervention in patients with vitreoretinal pathology coexisting with corneal wound. Although retina was attached in most of the cases, corneal graft survived only in one-fourth of patients and final visual acuities were poor.

Semi-automated kinetic perimetry provides additional information to static automated perimetry in the assessment of the remaining visual field in end-stage glaucoma.

PURPOSE: To test the hypothesis whether semi-automated kinetic perimetry (SKP) provides additional information to static automated perimetry (SAP) in the assessment of the remaining visual field in end-stage glaucoma, as defined by disc appearance (cup-to-disc ratio worse than 0.9) and SAP criteria (MD worse than 20 dB). METHODS: Fifty eyes of 44 patients presenting with end-stage glaucoma were examined first with SAP within the central 30° using stimulus size III, followed by SKP within 90° using test targets III4e and V4e. RESULTS: Overall, SKP provided additional information over SAP in more than half (54%) of the cases. In 16 instances (32%), SKP revealed visual field island beyond 30° that was undetected by SAP. In eight cases (16%), SKP showed both a central island and peripheral island of visual field. In three cases (6%) altitudinal scotomatous loss was found using SKP, but not in SAP. In 23 cases (46%) the central visual field island was defined both with SAP and SKP. The mean examination duration was 4 min for SAP and 9 min for SKP. CONCLUSIONS: In clinical practice, SKP with III4e and V4e test targets provides more information than 30° SAP regarding the remaining peripheral VF in patients with end-stage glaucoma; however, a longer test time is required for SKP.

Relationship between the area of isopters and Vigabatrin dosage during two years of observation.

BACKGROUND: The aim of the study was to evaluate the relationship between the area of isopters obtained using semi-automated kinetic perimetry (SKP) and Vigabatrin dosage in epilepsy patients with pretreatment baseline examination during 2-years of the follow-up. METHODS: 29 epilepsy patients were included into the study, but 15 individuals were excluded due to cognitive impairment, intracranial pathologies or eye diseases. Finally, 14 patients were examined with SKP before VGB treatment and after 6, 12, 18, and 24 months. Reaction time (RT)-corrected areas of three isopters (III4e, I4e and I2e) were measured for each of five examinations and compared intra-individually during 2-years period. Additionally, six epilepsy patients on other antiepileptic drugs were examined five times with SKP as a control. RESULTS: There was a significant decrease of I2e, I4e and III4e isopters' area during the follow-up of two years. Correlation was found between the I2e isopter's area and both cumulative dose and mean daily dose of VGB. With increasing RT, there was decreasing of all isopters' area in patients receiving VGB. In epilepsy patients who were not receiving VGB, there were no significance differences in isopters' area during follow-up. CONCLUSION: There was attenuation of area of III4e, I4e and I2e isopters obtained with SKP during a period of 2 years. RT, the cumulative dose and the mean daily dose of VGB influenced isopters' area obtained with SKP.

Solitary sarcoid granuloma of the iris mimicking tuberculosis: a case report.

Introduction. We report a case of a male patient presented with sarcoid lesions of the iris and conjunctiva, mimicking tuberculosis due to epithelioid cell granulomas with small central necrosis in conjunctival biopsy. Patient. A 25-year-old man was referred to our department for further management of an "iris tumor with iridocyclitis" in his right eye. Initial examination showed an isolated vascular tumor of the iris and ciliary body with anterior uveitis and mutton-fat keratic precipitates, suggesting the diagnosis of a granulomatous disease. Conjunctival biopsy revealed granulomatous epithelioid cell inflammation with small central necrosis without acid-fast bacilli. Extensive systemic examination, including bronchoscopy and transbronchial biopsy, provided the diagnosis of sarcoidosis stage 2 with pulmonary involvement, thus ruling out tuberculosis. Systemic and local steroid therapy was initiated, leading to complete recovery of our patient with complete disappearance of the iris lesion and improvement of the pulmonary function. Conclusion. Although noncaseating epithelioid cell granulomas are typical for sarcoidosis, small central necrosis can be found in some granulomas, leading to presumption of tuberculosis. Extensive systemic checkup in cooperation with other specialists is essential to confirm the correct diagnosis and to initiate the appropriate therapy.

Unilateral retinitis pigmentosa: 30 years follow-up.

This case report depicts the clinical course of a female patient with unilateral retinitis pigmentosa (RP), who presented first in 1984 at the age of 43 years. At the beginning, there were cells in the vitreous leading to the diagnosis of uveitis with vasculitis. Within 30 years, the complete clinical manifestation of RP developed with bone spicule-shaped pigment deposits, pale optic disc, narrowed arterioles, cystoid macular oedema, posterior subcapsular cataract, concentric narrowing of the visual field and undetectable electroretinogram signal. At the age of 72 years, there are still no signs of retinal dystrophy in the other eye.

Longitudinal analysis of progression in glaucoma using spectral-domain optical coherence tomography.

PURPOSE: To compare the longitudinal loss of RNFL thickness measurements by SD-OCT in healthy individuals and glaucoma patients with or without progression concerning optic disc morphology. METHODS: A total of 62 eyes, comprising 38 glaucomatous eyes with open angle glaucoma and 24 healthy controls, were included in the study (Erlangen Glaucoma Registry, NTC00494923). All patients were investigated annually over a period of 3 years by Spectralis SD-OCT measuring peripapillary RNFL thickness. By masked comparative analysis of photographs, the eyes were classified into nonprogressive and progressive glaucoma cases. Longitudinal loss of RNFL thickness was compared with morphological changes of optic disc morphology. RESULTS: Mixed model analysis of annual OCT scans revealed an estimated annual decrease of the RNFL thickness by 2.12 µm in glaucoma eyes with progression, whereas glaucoma eyes without progression in optic disc morphology lost 1.18 µm per year in RNFL thickness (P = 0.002). The rate of change in healthy eyes was 0.60 µm and thereby also significantly lower than in glaucoma eyes with progression (P < 0.001). The intrasession variability of three successive measurements without head repositioning was 1.5 ± 0.7 µm. The loss of mean RNFL thickness exceeded the intrasession variability in 60% of nonprogressive eyes, and in 85% of progressive eyes after 3 years. CONCLUSIONS: LONGITUDINAL MEASUREMENTS OF RNFL THICKNESS USING SD-OCT SHOW A MORE PRONOUNCED REDUCTION OF RNFL THICKNESS IN PATIENTS WITH PROGRESSION COMPARED WITH PATIENTS WITHOUT PROGRESSION IN GLAUCOMATOUS OPTIC DISC CHANGES. (www.clinicaltrials.gov number, NTC00494923.).

Glaucoma diagnostic performance of GDxVCC and spectralis OCT on eyes with atypical retardation pattern.

PURPOSE: To investigate the impact of typical scan score (TSS) on discriminating glaucomatous and healthy eyes by scanning laser polarimetry and spectral domain optical coherence tomography (SD-OCT) in 32 peripapillary sectors. PATIENTS AND METHODS: One hundred two glaucoma patients and 32 healthy controls underwent standard automated perimetry, 24-hour intraocular pressure profile, optic disc photography, GDxVCC, and SD-OCT measurements. For controls, only very typical scans (TSS=100) were accepted. Glaucoma patients were divided into 3 subgroups (very typical: TSS=100; typical: 99≥TSS≥80, atypical: TSS<80). Receiver operating characteristic curves were constructed for mean retinal nerve fiber layer values, sector data, and nerve fiber indicator (NFI). Sensitivity was estimated at ≥90% specificity to compare the discriminating ability of each imaging modality. RESULTS: For discrimination between healthy and glaucomatous eyes with very typical scans, the NFI and inferior sector analyses 26 to 27 demonstrated the highest sensitivity at ≥90% specificity in GDxVCC and SD-OCT, respectively. For the typical and atypical groups, sensitivity at ≥90% specificity decreased for all 32 peripapillary sectors on an average by 10.9% and 17.9% for GDxVCC and by 4.9% and 0.8% for SD-OCT. For GDxVCC, diagnostic performance of peripapillary sectors decreased with lower TSS, especially in temporosuperior and inferotemporal sectors (sensitivity at ≥90% specificity decreased by 55.3% and by 37.8% in the atypical group). CONCLUSIONS: Diagnostic accuracy is comparable for SD-OCT and GDxVCC if typical scans (TSS=100) are investigated. Decreasing TSS is associated with a decrease in diagnostic accuracy for discriminating healthy and glaucomatous eyes by scanning laser polarimetry. NFI is less influenced than the global or sector retinal nerve fiber layer thickness. The TSS score should be included in the standard printout. Diagnostic accuracy of SD-OCT is barely influenced by low TSS.

Plasma homocysteine levels in patients with normal tension glaucoma.

PURPOSE: To investigate whether there is an association of elevated plasma levels of homocysteine (Hcy) and normal tension glaucoma (NTG). PATIENTS AND METHODS: Plasma levels of Hcy (fluorescence polarization immunoassay), vitamin B6 (high-performance liquid chromatography), vitamin B12, and folate levels (immunoassay) were determined in 42 patients with NTG and in 42 age-matched and sex-matched controls. RESULTS: No significant difference regarding Hcy (NTG: 10.95 µmol/L±2.65; controls: 11.29 µmol/L±2.76) (P=0.639), vitamin B6 (NTG: 14.45 ng/mL±12.89; controls: 13.57 ng/mL±10.41) (P=0.629), vitamin B12 (NTG: 387.73 pg/mL±282.04; controls: 423.27 pg/mL±188.85) (P=0.052) and folate (NTG: 9.45ng/mL±3.42; controls: 10.82 ng/mL±4.48) (P=0.181) levels were found between both groups. CONCLUSIONS: An association of elevated Hcy levels and NTG was not found and therefore a role of Hcy as a modifiable risk factor in the pathogenesis of NTG seems unlikely.

Retinal nerve fiber layer thickness in normals measured by spectral domain OCT.

PURPOSE: To determine normal values for peripapillary retinal nerve fiber layer thickness (RNFL) measured by spectral domain Optical Coherence Tomography (SOCT) in healthy white adults and to examine the relationship of RNFL with age, gender, and clinical variables. PATIENTS AND METHODS: The peripapillary RNFL of 170 healthy patients (96 males and 74 females, age 20 to 78 y) was imaged with a high-resolution SOCT (Spectralis HRA+OCT, Heidelberg Engineering) in an observational cross-sectional study. RNFL thickness was measured around the optic nerve head using 16 automatically averaged, consecutive circular B-scans with 3.4-mm diameter. The automatically segmented RNFL thickness was divided into 32 segments (11.25 degrees each). One randomly selected eye per subject entered the study. RESULTS: Mean RNFL thickness in the study population was 97.2 ± 9.7 µm. Mean RNFL thickness was significantly negatively correlated with age (r = -0.214, P = 0.005), mean RNFL decrease per decade was 1.90 µm. As age dependency was different in different segments, age-correction of RNFL values was made for all segments separately. Age-adjusted RNFL thickness showed a significant correlation with axial length (r = -0.391, P = 0.001) and with refractive error (r = 0.396, P<0.001), but not with disc size (r = 0.124). CONCLUSIONS: Normal RNFL results with SOCT are comparable to those reported with time-domain OCT. In accordance with the literature on other devices, RNFL thickness measured with SOCT was significantly correlated with age and axial length. For creating a normative database of SOCT RNFL values have to be age adjusted.

Circadian intraocular pressure profiles in chronic open angle glaucomas.

PURPOSE: To evaluate circadian intraocular pressure (IOP) profiles in eyes with different types of chronic open-angle glaucoma (COAG) and normal eyes. METHODS: This study included 3,561 circadian IOP profiles obtained from 1,408 eyes of 720 Caucasian individuals including glaucoma patients under topical treatment (1,072 eyes) and normal subjects (336 eyes). IOP profiles were obtained by Goldmann applanation tonometry and included measurements at 7 am, noon, 5 pm, 9 pm, and midnight. RESULTS: Fluctuations of circadian IOP in the secondary open-angle glaucoma (SOAG) group (6.96±3.69 mmHg) was significantly (P<0.001) higher than that of the normal pressure glaucoma group (4.89±1.99 mmHg) and normal eyes (4.69±1.95 mmHg); but the difference between the two latter groups was not significant (P=0.47). Expressed as percentages, IOP fluctuations did not vary significantly among any of the study groups. Inter-ocular IOP difference for any measurement was significantly (P<0.001) smaller than the profile fluctuations. In all study groups except the SOAG group, IOP was highest at 7 am, followed by noon, 5 pm, and finally 9 pm or midnight. In the SOAG group, mean IOP measurements did not vary significantly during day and night. CONCLUSIONS: In contrast to normal eyes and eyes with primary open-angle glaucoma under topical antiglaucoma treatment, eyes with SOAG under topical treatment do not show the usual circadian IOP profile in which the highest IOP values occur in the morning, and the lowest in the evening or at midnight. These findings may have implications for timing of tonometry. Fluctuation of circadian IOP was highest in SOAG compared to other types of open angle glaucomas.

Comparison of scanning laser polarimetry and optical coherence tomography in quantitative retinal nerve fiber assessment.

PURPOSE: To investigate the relationship between retinal nerve fiber layer (RNFL) measurements in corresponding areas obtained with scanning laser polarimetry and optical coherence tomography and to compare their discriminating ability in the diagnosis of preperimetric and perimetric glaucoma. PATIENTS AND METHODS: Three hundred eighty-six subjects-57 healthy controls, 145 ocular hypertensive patients, 89 with preperimetric glaucoma, and 95 with perimetric glaucoma-were recruited from the Erlangen Glaucoma Registry. Perimetry, 24-hours intraocular pressure profile, stereographic optic disc slides, optical coherence tomography StratusOCT, and scanning laser polarimetry GDx VCC (Carl Zeiss Meditec, Inc, Dublin, CA) were performed in all patients. Receiver operating characteristic (ROC) curves were constructed for mean RNFL values, sector data, and indices. Sensitivity was estimated at >or=90% and >or=80% of specificity to compare the discriminating ability of each imaging modality. RESULTS: For discrimination between glaucomatous and healthy eyes in GDx VCC the nerve fiber index demonstrated the largest area under the ROC curve (AUROC) (0.962+/-0.013), whereas in StratusOCT the largest AUROC (0.986+/-0.006) was found in the inferior quadrant. For preperimetric glaucoma detection the nerve fiber index achieved the largest AUROC (0.783+/-0.037). In contrast, the total RNFL average obtained using StratusOCT showed the largest AUROC (0.904+/-0.025). Bland-Altman plots showed good agreement between both instruments. CONCLUSIONS: Both the GDx VCC and StratusOCT demonstrate increasing RNFL loss with advanced glaucomatous damage and were comparable in the diagnosis of perimetric glaucoma. Preperimetric glaucomatous damage may be better assessed by StratusOCT.

Influence of glaucomatous damage and optic disc size on glaucoma detection by scanning laser tomography.

PURPOSE: To investigate the impact of glaucomatous damage and optic disc size on different automated Heidelberg Retina Tomograph classifications for discriminating glaucoma and healthy controls. PATIENTS AND METHODS: Two hundred seventy-three glaucoma patients and 276 healthy controls were recruited from the Erlangen Glaucoma Registry. Standard static white on white perimetry, 24-hour intraocular pressure profile, stereographic optic disc slides, and scanning laser tomography were performed in all patients and controls. The effect of glaucoma stage and disc size on the diagnostic accuracy was evaluated using receiver operating characteristic curves. Results of the Glaucoma Probability Score were compared with other recently described multivariate classifications. RESULTS: Areas under the receiver operating characteristic curves for discrimination between glaucoma and healthy eyes of the overall classification by Glaucoma Probability Score, Moorfields regression analysis, Bathija, Iester, Mikelberg, and Mardin increased from 0.71, 0.65, 0.70, 0.67, 0.65, and 0.63 for early glaucoma (Jonas: stage I) to 0.96, 0.95, 0.94, 0.94, 0.92, and 0.88 for advanced glaucomatous damage (Jonas: stage IV). Best performance of discrimination between glaucoma and healthy eyes using area under the receiver operating characteristic curve's were observed for medium-sized discs (2.1 to 2.49 mm) and worst performance for large optic discs (>3.1 mm). Glaucoma Probability Score classification was superior to other investigated classifications in most of the investigated subgroups. CONCLUSIONS: The diagnostic accuracy of all classifications depends on the optic disc size and the glaucoma stage. Glaucoma Probability Score showed a better diagnostic performance than Moorfields regression analysis and was similar to that of Bathija.

Visualization of changes of the iris configuration after peripheral laser iridotomy in primary melanin dispersion syndrome using optical coherence tomography.

Pigment or melanin dispersion syndrome is characterized by radial iris transillumination defects, retrocorneal Krukenberg spindle, and dense trabecular pigmentation. Reverse pupillary block has been presumed as one possible pathogenetic mechanism for backward bowing of the iris leading to iris-zonular rubbing and distribution of melanin granules in the anterior chamber. Laser iridotomy is recommended as a treatment to prevent further melanin dispersion and development of pigmentary glaucoma. The effect of Nd:YAG laser iridotomy as a prophylactic and potentially causal treatment in melanin dispersion syndrome can be easily visualized by optical coherence tomography as a fast and noncontact procedure.

Measuring contrast sensitivity in normal subjects with OPTEC 6500: influence of age and glare.

BACKGROUND: The purpose of this study was to develop age-related curves for contrast sensitivity (CS) in normal subjects under day and night conditions with and without glare. METHODS: Sixty-one healthy eyes from 61 subjects were measured with the OPTEC(R) 6500 P under day and night conditions (luminance levels: 85 cd/m(2) and 3.0 cd/m(2) with and without glare; spatial frequencies: 1.5, 3, 6, 12 and 18 cycles/degree). A reliability analysis with five repeated measurements of six persons on 4 days was performed to examine the repeatability. The influence of age on contrast sensitivity, forward and backward scatter was examined by means of linear regression. RESULTS: Contrast sensitivity was significantly reduced under night conditions with glare, whereas glare had less influence under daylight illumination. Mean reliability coefficients are 0.87 (day), 0.77 (day with glare), 0.69 (night) and 0.81 (night with glare), which suggests sufficient retest reliability of the device. Regression analyses showed a highly significant influence of age, but the variance of the measurement values is not explained by age alone. The coefficients of determination for the regression of area under the log contrast sensitivity function (AULCSF) on age are 0.33 (photopic), 0.34 (photopic with glare), 0.29 (mesopic) and 0.36 (mesopic with glare, p < 0.0001 in all cases). CONCLUSION: A significant relationship between age, CS and scatter was confirmed in our study. The results provide baseline values for the examination of patients with different diseases in which contrast sensitivity is impaired (such as glaucoma, cataracts and amblyopia) and might be useful in studies of roadworthiness or in investigation of the impact of intraocular lenses.