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Zusammenfassung Hintergrund Untersuchung der langfristigen Effizienz und Sicherheit der transskleralen Lasertherapie (TLT) mittels MicroPulse über 24 Monate bei Patienten mit primärem Offenwinkelglaukom (POWG). Material und Methoden In dieser prospektiven interventionellen Fallserie wurden die Daten von 44 Augen von medikamentös behandelten POWG-Patienten ausgewertet, die eine MicroPulse-TLT erhielten, um eine weitere Senkung des Augeninnendrucks (IOD) zu erreichen. Es wurden die Reduktion des 24-h-IODs, der zirkadianen IOD-Fluktuationen und der IOD-Spitzen nach 3, 12 und 24 Monaten untersucht. Zudem sollten postoperative Komplikationen, die Misserfolgsquote und Einflussfaktoren auf den Therapieerfolg analysiert werden. Ergebnisse Der IOD ist von 16,1 ± 3,4 mmHg präoperativ auf 13,0 ± 2,9 mmHg (n = 31; p Schlussfolgerung Die MicroPulse-TLT zeigt eine gute IOD-Senkung bei Patienten mit primärem Offenwinkelglaukom und maximal tolerierter drucksenkender Lokaltherapie, wobei etwa 50% der Augen ihren individuellen Zieldruck erreichten.

PURPOSE Chronic hyperglycemia induces morphological and functional changes of the cornea. Corneal clarity is essential for visual function, and the measurement of corneal optical density (COD) might provide further information on diabetes mellitus (DM)-induced alterations. METHODS COD of patients with DM and age-matched healthy subjects was measured using the Pentacam HR. Furthermore, central and thinnest corneal thickness and peripheral pachymetry of concentric circles around thinnest corneal thickness were investigated. In DM, information on disease duration, type, presence of diabetic retinopathy and maculopathy, and HbA1c value was recorded. RESULTS In this study, 76 patients with DM and 65 healthy subjects were included. In patients with DM, the COD values of nearly all corneal layers and zones were reduced in comparison with healthy subjects (P < 0.05). Furthermore, the COD measurements were inversely correlated with the HbA1c value (total COD central layer: r = -0.424, P = 0.044) and stage of diabetic retinopathy (total COD: r = -0.271, P = 0.019). Diabetic patients with maculopathy revealed lower total COD values than patients without maculopathy (16.5 ± 5.6 vs. 21 ± 7.6, P = 0.031), and COD was lower in DM type 1 than in type 2 (16.1 ± 5.1 vs. 20.8 vs. 7.5, P = 0.035). In both groups, the COD values increased with age (patients with DM: r = 0.336, P = 0.003; healthy subjects: r = 0.679, P < 0.001) and decreased with peripheral corneal thickness increase. CONCLUSIONS In patients with DM, COD was significantly reduced in comparison with healthy subjects. These changes were associated to disease-specific factors and measurements of peripheral corneal thickness profiles.

To determine the long-term efficacy and safety of MicroPulse transscleral laser therapy (TLT) over a 24-month period in patients with primary open angle glaucoma.This prospective interventional case series evaluated data from 44 medically treated eyes of primary open angle glaucoma (POAG) patients who received MicroPulse TLT to achieve further reduction in IOP. The reduction in 24-hr mean diurnal intraocular pressure (IOP), diurnal IOP fluctuations, and peak IOP were monitored after 3, 12, and 24 months. Postoperative complications, failure rates, and factors influencing IOP reduction were also evaluated.IOP decreased from 16.1 ± 3.4 mmHg preoperatively to 13.0 ± 2.9 mmHg (n = 31; p 0.001), 12.3 ± 3.0 mmHg (n = 27; p 0.001), and 13.1 ± 2.6 mmHg (n = 23; p 0.001) at the 3-month, 12-month and 24-month follow-ups. At 24 months, 23 eyes (52%) had a sufficient IOP reduction to reach the individual target pressure. No severe complications were observed. No parameters could be identified that correlated with successful IOP reduction after treatment. The highest failure rate was observed during the first 3 months and remained stable thereafter.For about 50% of POAG eyes receiving the maximum tolerated treatment, MicroPulse TLT proved an effective method of further lowering IOP so as to reach the individual target pressure.Untersuchung der langfristigen Effizienz und Sicherheit der transskleralen Lasertherapie (TLT) mittels MicroPulse über 24 Monate bei Patienten mit primärem Offenwinkelglaukom (POWG).In dieser prospektiven interventionellen Fallserie wurden die Daten von 44 Augen von medikamentös behandelten POWG-Patienten ausgewertet, die eine MicroPulse-TLT erhielten, um eine weitere Senkung des Augeninnendrucks (IOD) zu erreichen. Es wurden die Reduktion des 24-h-IODs, der zirkadianen IOD-Fluktuationen und der IOD-Spitzen nach 3, 12 und 24 Monaten untersucht. Zudem sollten postoperative Komplikationen, die Misserfolgsquote und Einflussfaktoren auf den Therapieerfolg analysiert werden.Der IOD ist von 16,1 ± 3,4 mmHg präoperativ auf 13,0 ± 2,9 mmHg (n = 31; p 0,001) nach 3 Monaten, 12,3 ± 3,0 mmHg (n = 27; p 0,001) nach 12 Monaten und 13,1 ± 2,6 mmHg (n = 23; p 0,001) nach 24 Monaten gesunken. Nach 24 Monaten erreichten 23 Augen (52%) ihren individuellen Zieldruck. Es traten keine schwerwiegenden postoperativen Komplikationen auf. Es konnten keine Einflussfaktoren auf den Therapieerfolg identifiziert werden. Das häufigste Therapieversagen war innerhalb der ersten 3 postoperativen Monate zu beobachten und blieb danach nahezu stabil.Die MicroPulse-TLT zeigt eine gute IOD-Senkung bei Patienten mit primärem Offenwinkelglaukom und maximal tolerierter drucksenkender Lokaltherapie, wobei etwa 50% der Augen ihren individuellen Zieldruck erreichten.

PURPOSE Diabetes mellitus (DM) induces changes in corneal biomechanical properties. The influence of disease-specific factors was evaluated, and a novel DM index was created. METHODS Eighty-one patients with DM and 75 healthy subjects were matched according to age, intraocular pressure, and central corneal thickness. Information on the disease was collected, and measurements with the Ocular Response Analyzer and the Corvis ST were taken. Results were compared between the groups, and the influence of disease-specific factors was evaluated. From dynamic corneal response parameters, a DM index was calculated. RESULTS In DM, corneal hysteresis was higher than in healthy subjects (10.5 ± 1.9 vs. 9.7 ± 1.9 mm Hg, P = 0.008). In addition, dynamic corneal response parameters showed significant differences. Among others, highest concavity (HC) (17.212 ± 0.444 vs. 16.632 ± 0.794 ms, P < 0.001) and A2 time (21.85 ± 0.459 vs. 21.674 ± 0.447 ms, P = 0.017) as well as A1 (0.108 ± 0.008 vs. 0.104 ± 0.011 mm, P = 0.019) and A2 deflection amplitudes (0.127 ± 0.014 vs. 0.119 ± 0.014 mm, P < 0.001) were increased in DM. In DM type 1, HC deformation amplitude (1.14 ± 0.19 vs. 1.095 ± 0.114 mm, P = 0.035) was higher than in type 2. The time of deflection amplitude max correlated with the severity of retinopathy (R = 0.254, P= 0.023). In case of diabetic maculopathy, A1 velocity (0.155 ± 0.018 vs. 0.144 ± 0.019 ms, P = 0.043) and A2 time (22.052 ± 0.395 vs. 21.79 ± 0.46 ms, P = 0.04) were increased. Deformation amplitude max (R = 0.297, P = 0.024), HC time (R = 0.26, P = 0.049), HC deformation amplitude (R = 0.297, P = 0.024), and A2 deformation amplitude (R = 0.276, P = 0.036) were associated to disease duration. The DM index revealed a sensitivity of 0.773 and a specificity of 0.808 (area under the curve of receiver operating characteristic = 0.833). CONCLUSIONS In DM, changes in corneal biomechanics were correlated with disease-specific factors. The DM index achieved reliable sensitivity and specificity values.

Purpose: To investigate the influence of chronic hyperglycemia in diabetes mellitus (DM) on spatial corneal thickness distribution and to analyze the influence of disease-specific factors. Methods: DM patients and healthy subjects were matched according to age and intraocular pressure (IOP). In diabetics, disease duration, DM type, and HbA1c value were assessed. Spatially resolved corneal thickness was measured by Pentacam HR. Thinnest corneal thickness (TCT) and peripheral pachymetry of concentric circles around TCT were determined. The Dynamic Scheimpflug Analyzer Corvis ST (CST) was used to measure the parameter pachy slope, which is an indicator of the change of corneal thickness from the apex to the periphery. Results: 59 DM patients and 57 healthy subjects were included. Age (P = .486) and IOP (P = .154) were not different between the groups. In DM, pachy slope was significantly higher than in healthy subjects (41.1 ± 9.87 vs. 35.18 ± 10.64 μm, P = .004). Also, the differences between TCT and the average of peripheral corneal thickness of concentric circles with a diameter of 2 mm (10.3 ± 1.7 vs. 9.3 ± 3.8 μm, P

To investigate orbital biomechanical properties in patients with thyroid orbitopathy and in age- and gender-matched healthy subjects using the Corvis-ST (CST, Oculus Wetzlar, Germany).The CST allows a non-contact tonometry with an ultra-high-speed Scheimpflug device to record the deformation of the cornea during an air pulse. Biomechanical response parameters (intraocular pressure (IOP), whole eye movement length (WEMl) and time (WEMt), deflection amplitude 2 mm ratio max, deflection amplitude max, stiffness parameter, and biomechanically corrected IOP were measured in 39 patients with thyroid orbitopathy (= group I) and in 33 age- and gender-matched healthy subjects (= group II) using the CST.Mean age in group I was 54.3 ± 11.6 years and in group II 54.2 ± 12.3 years with no statistical significant difference between the groups (P = 0.98). The gender distribution between the groups was not statistically significantly different (P = 0.51). Mean central corneal thickness was 571 ± 30 µm in group I and 563 ± 36 µm in group II (P = 0.306). There were statistically significant differences (P 0.001) between groups I and II in mean IOP (19.3 ± 4.5 vs. 14.8 ± 2.3 mmHg, mean biomechanically corrected IOP (17.1 ± 3.4 vs. 13.4 ± 2.1 mmHg), mean WEMl (207 ± 57 vs. 322 ± 50 µm), mean WEMt (20.5 ± 1.0 vs. 21.9 ± 0.7 ms), mean IOP-adjusted WEMl (213 ± 56 vs. 314 ± 62 µm), and in mean stiffness parameter (132.5 ± 29.6 vs. 107.8 ± 23.3 mmHg/mm), respectively.Biomechanical parameters as measured by the CST were significantly reduced in patients with thyroid orbitopathy compared to age- and gender-matched healthy subjects, indicating a reduction in orbital compliance in thyroid orbitopathy. The parameters WEMl and WEMt might be a useful diagnostic tool to evaluate the condition of the eyeball within the orbit.

Purpose To investigate fundus autofluorescence (FAF) lifetimes in geographic atrophy (GA) with a focus on macular pigment (MP) and foveal sparing. Methods The study included 35 eyes from 28 patients (mean age 79.2 ± 8.0 years) with GA. A 30° retinal field, centred at the macula, was investigated using fluorescence lifetime imaging ophthalmoscopy (FLIO). The FLIO technology is based on a Heidelberg Engineering Spectralis system. Decays of FAF were detected in a short (498–560 nm, SSC) and long (560–720 nm, LSC) spectral channel. The mean fluorescence lifetime, τm, was calculated from a three-exponential approximation of the FAF decays. Macular optical coherence tomography (OCT) scans as well as fundus photography were recorded. Results Review of FLIO data reveals specific patterns of significantly prolonged τm in regions of GA (SSC 616 ± 343 ps, LSC 615 ± 154 ps) as compared to non-atrophic regions. Large τm differences between the fovea and atrophic areas correlate with better visual acuity (VA). Shorter τm at the fovea than within other non-atrophic regions indicates sparing, which was identified in 16 eyes. Seventy per cent of patients treated with lutein supplementation showed foveal sparing, whereas the rate among non-supplemented patients was 22%. Conclusion Using FLIO, we present a novel way to detect foveal sparing, investigate MP, and analyse variability of τm in different foveal regions (including the prognostic valuable border region) in GA. These findings support the potential utility of FLIO in monitoring disease progression. The findings also highlight the possibly protective effect of lutein supplementation, with implication in recording the presence and distributional pattern of MP.

To investigate optic nerve head (ONH) pallor quantitatively in patients with primary open-angle glaucoma (POAG) and in healthy subjects, and to examine the relationship to mean deviation in perimetry (MD), cup-disk ratio (CDR), and diameters of retinal vessels.A total of 89 POAG patients (67.6 ± 11.1 years) and 48 healthy subjects (63.3 ± 14 years) were included. A dual-bandpass transmission filter was introduced in the illumination path of the fundus camera of the Dynamic Vessel Analyzer (Imedos Systems UG) and two monochromatic images at different wavelenghts (548 ± 10 and 610 ± 10 nm) were recorded simultaneously. ONH pallor was defined as the quotient of light reflection in both spectral channels. Pallor values were averaged over four fields which were positioned on the ONH. The mean of these measurements was calculated. In 47 of 89 POAG patients diameters of retinal vessels were determined peripapillary.In POAG, the ONH showed a significantly higher pallor value compared to healthy subjects (82.34 ± 19.28 vs. 62.67 ± 10.41, p0.001). ONH pallor was correlated to indicators used to estimate disease severity: MD (r = -0.565, p0.001) and CDR (r = 0.561, p0.001). The pallor value was associated to diameters of retinal arterioles (r = -0.313, p = 0.032) and venules (r = -0.397, p = 0.006).Pallor determined by this method was higher in POAG patients than in healthy subjects and increased in patients with advanced disease. ONH pallor might result from a reduced blood perfusion of the ONH or tissue atrophy accompanied by vessel obliteration in POAG. By measuring ONH pallor additional diagnostic information about the vitality of the neuroretinal rim might be gained in glaucoma patients.

Purpose: To investigate the impact of diabetes mellitus–induced changes on intraocular pressure measurements using Goldmann applanation tonometry, Ocular Response Analyzer, and Corvis ST. Methods: Measurements were done using Goldmann applanation tonometry, Ocular Response Analyzer, and Corvis ST in 69 diabetic patients. Biomechanical-corrected intraocular pressure values by Ocular Response Analyzer (IOPcc) and Corvis ST (bIOP) were used. In addition, biometry and tomography were performed and information on diabetes mellitus specific factors was collected. Results were compared to an age-matched group of 68 healthy subjects. Results: In diabetes mellitus, Goldmann applanation tonometry intraocular pressure (P = 0.193) and central corneal thickness (P = 0.184) were slightly increased. Also, IOPcc (P = 0.075) and bIOP (P = 0.542) showed no significant group difference. In both groups, IOPcc was higher than Goldmann applanation tonometry intraocular pressure (P = 0.002, P Conclusion: In diabetes mellitus, Goldmann applanation tonometry intraocular pressure was slightly, but not significantly, increased, which might be caused by a higher central corneal thickness and changes in corneal biomechanical properties. However, intraocular pressure values measured by Ocular Response Analyzer and Corvis ST were not significantly different between diabetes mellitus patients and healthy subjects. The bIOP showed a higher agreement with Goldmann applanation tonometry than IOPcc and was independent from central corneal thickness.

Purpose. To compare intraocular pressure (IOP) measurements with Goldmann applanation tonometry (GAT), ocular response analyzer (ORA), dynamic contour tonometer (DCT), and Corvis ST (CST) in healthy subjects. Methods. In a prospective, observational study, IOP measurements with GAT (GAT-IOPc), ORA (IOPcc), DCT (DCT-IOP), and CST (bIOP) were performed and analyzed in 94 healthy subjects. Results. Mean age of the participants was 45.6 ± 17.2 years (range 18 to 81 years). Mean GAT-IOPc was 12.9 ± 2.4 mmHg, mean DCT-IOP was 16.1 ± 2.6 mmHg, and mean IOPcc was 15.6 ± 3.3 mmHg. DCT-IOP and IOPcc were significantly higher than GAT-IOPc (P<0.001). Mean bIOP was 13.5 ± 2.4 mmHg that was slightly higher but not significantly different from GAT-IOPc (P=0.146). Correlation analysis of IOP values and central corneal thickness (CCT) revealed a negative correlation between GAT-IOPc and CCT (r = −0.347; P=0.001). However, IOPcc, DCT-IOP, and bIOP showed no significant correlation to CCT. Only bIOP revealed a weak but significant age dependency (r = 0.321, P=0.002). Conclusion. All tonometry devices showed a good agreement of biomechanical corrected IOP values with GAT-IOPc. As no influence of CCT on IOPcc, DCT-IOP, and bIOP was detectable, the used correction algorithms appear to be appropriate in these tonometers in the clinical setting. The highest agreement was found between GAT-IOPc and bIOP. However, bIOP weakly correlated with participants’ age. Further studies are needed to elucidate the role of bIOP for IOP measurement.

Retinal oxygen saturation (SO2) during flicker light stimulation was measured non-invasively in humans with age-related macular degeneration (AMD). Furthermore, the differences between early and late stages of AMD were evaluated. In 60 eyes of 45 AMD patients (74 ± 8.3 years) and 23 eyes of 23 healthy controls (73.4 ± 7.4 years), the SO2 of arterioles and venules was measured with the oximetry module of the Retinal Vessel Analyzer. Arterial SO2, venous SO2 and arteriovenous SO2 difference at baseline and with the flicker were assessed and compared with controls. From the difference between the arteriovenous SO2 under flicker stimulation and at baseline, the parameter delta av. Diff was calculated. Subgroup analyses of non-exudative (dry) AMD, exudative (wet) AMD and their end stages, geographic atrophy (GA) and disciform scar (DS) were performed. In comparison with healthy subjects (mean − 4.90, CI [− 6.32, − 3.43]), the parameter delta av. Diff was significantly reduced in all AMD patients (mean − 2.20, CI − 3.15, −1.23, p = 0.003), dry AMD (mean − 1.97, CI − 3.31, −0.63, p = 0.013) and wet AMD (mean − 2.35, CI − 3.50, − 1.19, p = 0.025). The comparison between wet and dry AMD revealed no significant results (p = 1). The comparison between AMD subgroups and healthy controls (median (IQR) − 4.29 (− 8.32; − 2.42) %) showed significant differences in non-neovascular (early dry AMD) (median (IQR) − 2.43 (− 4.59; − 0.74) %, p = 0.038), GA (median (IQR) 0.10 (− 4.02; 3.15) %, p = 0.019) and DS (median (IQR) − 1.67 (− 3.52; − 0.12) %, p = 0.03). A nearly significant reduction was observed in exudative (early wet) AMD (median (IQR) − 2.71 (− 5.84; − 0.2) %, p = 0.055). Minimal, not statistically significant differences of delta av. Diff were found between AMD subgroups. None of the baseline parameters was significantly different between patients and healthy controls, even after flicker light stimulation. Non-invasive retinal oximetry with flicker light stimulation seems to be a suitable method to study the pathogenetic mechanisms of AMD. The mathematically derived parameter delta av. Diff appears to be more sensitive than arteriovenous SO2 difference. Results suggest that the regulation of retinal oxygen supply, oxygen consumption or both is impaired in AMD.

Hyperglycemia in diabetes mellitus (DM) might induce changes in corneal biomechanics. Therefore, biomechanical properties of the cornea were measured using the ocular response analyzer and the Corvis ST.In the study, 35 eyes of 35 diabetic patients were included. After an ophthalmological examination, measurements with the ocular response analyzer and the Corvis ST were taken. Additionally, biometry and corneal topography were performed and HbA1c values were collected. Results were compared to an age-, pachymetry- and intraocular pressure-matched group of 35 healthy subjects.Mean age (67.6 ± 10.3; 64.1 ± 8.3 years), intraocular pressure (13.4 ± 2.9; 12.8 ± 2.8 mm Hg), and central corneal thickness (556.4 ± 31.7; 548.6 ± 32.9 μm) were not significantly different between the groups (P0.05). In DM, the corneal hysteresis (CH) and the corneal resistance factor (CRF) were increased (CH: 10.8 ± 2 vs. 9.4 ± 1.6, P = 0.002; CRF: 10.6 ± 2.1 vs. 9.6 ± 1.5, P = 0.022). Also, most dynamic corneal response parameters showed significant differences. Beside others, A1 and A2 deflection amplitudes were increased (P0.001) and highest concavity and A2 time were extended (P0.001 and 0.007) in DM. According to current HbA1c value, DM was classified as controlled (≤7%) and poorly controlled (7%) and significant biomechanical differences were measured between both groups.In DM, significant changes in corneal biomechanical properties were detectable. In patients, CH and CRF were increased and most dynamic corneal response parameters were different compared to healthy subjects.

Purpose To investigate corneal biomechanical parameters in healthy and keratoconic eyes using the Ocular Response Analyzer dynamic bidirectional applanation device (ORA) and the Corvis ST dynamic Scheimpflug analyzer (CST). Setting Department of Ophthalmology, Carl Gustav Carus University Hospital Dresden, Germany. Design Prospective, monocentric, case-control study. Methods Corneal biomechanical parameters were obtained in 60 eyes of 60 healthy participants (Group I) and 60 eyes of 60 keratoconus patients (Group II) with different grades of severity using the ORA and the CST. Participants were matched by age (Group I: 38.3 years ± 12.8 [SD], Group II: 37.3 ± 11.2 years) and intraocular pressure (Group I: 13.7 ± 1.7 mm Hg, Group II: 13.6 ± 1.5 mm Hg). Results For the ORA, the receiver operating characteristic curve analysis showed an area under the curve (AUC) of 0.950 for the keratoconus score, a sensitivity of 87% and a specificity of 93%. The AUC for the corneal resistant factor and corneal hysteresis was 0.930 and 0.868 with a sensitivity of 87% and a specificity of 87%, and sensitivity of 80% and a specificity of 80%, respectively. For the CST, the corneal biomechanical index showed the highest AUC (0.977) with a sensitivity of 97% and a specificity of 98%. The AUC of integrated radius (0.974; 90% sensitivity, 93% specificity) was followed by maximum inverse radius (0.962; 92% sensitivity, 93% specificity). Most parameters were able to discriminate healthy eyes from different keratoconus stages and early stages of keratoconus from moderate stages. Conclusion Both devices allowed for good differentiation between healthy eyes and keratoconic eyes and between different severity grades of keratoconus. Several parameters of ORA and CST revealed high sensitivity and specificity values for keratoconus detection.

Anna Leszczynska,* Lisa Ramm,* Eberhard Spoerl, Lutz E Pillunat, Naim Terai Department of Ophthalmology, University Hospital Dresden, Dresden, Germany *These authors contributed equally to this work Introduction: To investigate the effect of acupuncture on different ocular blood flow (OBF) parameters in patients with primary open-angle glaucoma (POAG). Patients and methods: In a prospective, randomized study, 56 POAG patients were randomly assigned either to an eye-specific acupuncture (group I, n=28) or to an eye-unspecific acupuncture treatment (group II, n=28). Blood flow parameters were measured before and 10 minutes after treatment. Parapapillary retinal blood flow was determined by the Heidelberg retina flowmeter. Retinal vessel diameters were measured by the dynamic vessel analyzer. Pulsatile ocular blood flow, ocular pulse amplitude, and IOP were investigated by the Langham OBF system. Systemic blood pressure was obtained additionally. Results: Pulsatile ocular blood flow increased significantly after the eye-specific acupuncture treatment from 5.6±4.3 to 6.7±4.9 µL/min (P=0.014). There was no significant change in parapapillary retinal blood flow, retinal vessel diameter, systemic blood pressure, or IOP after treatment in neither of the two groups. Conclusion: An eye-specific acupuncture treatment may affect OBF in POAG patients. Keywords: acupuncture, glaucoma, ocular blood flow, retinal vessel diameter, Heidelberg retina flowmeter, Langham ocular blood flow system, dynamic vessel analyzerA Letter to the Editor has been received and published for this article.

To examine the supply of oxygen to the retina in primary open-angle glaucoma (POAG). Forty-one patients with primary open-angle glaucoma (mean age 64.1 ± 12.9 years) and 40 healthy subjects (63.6 ± 14.1 years) were included. Fundus images, centered at the optic disc, were taken using the Retinal Vessel Analyzer (RVA). The vessel diameters were calculated as central retinal artery (CRAE) and vein equivalent (CRVE) from diameter measurements in the peripapillary vessels. The oxygen saturation of the arteries and veins was investigated employing a two-wavelengths technique. After the measurement at baseline, the vascular response to flicker light exposure was measured. In glaucoma patients the mean oxygen saturation of the retinal veins at baseline was higher than in the healthy controls (64.36 ± 7.11 vs. 59.78 ± 8.47, p = 0.01), whereas the mean arteriovenous oxygen saturation difference was lower (33.07 ± 5.24 vs. 37.53 ± 6.95, p = 0.002). The arterial oxygen saturation as well as the arterial and venous diameters showed no difference between the groups. The increase of the CRVE during flicker light stimulation (3.72 ± 3.29 % vs. 5.43 ± 4.04, p = 0.039), as well as the change of the venous oxygen saturation (2.08 ± 3.74 % vs. 4.18 ± 3.88 %, p = 0.016) and the arteriovenous saturation difference (−2.1 ± 3.31 % vs. −4.43 ± 3.6 %, p = 0.003) were smaller in POAG patients than in the healthy group. The reduction in the arteriovenous difference in oxygen saturation in POAG patients might show a decreased oxygen demand of the retina caused by the glaucomatous loss of neuroretinal tissue. The lower extent of the flicker light-induced change of the diameter of retinal veins and the venous oxygen saturation could indicate an impairment of blood flow regulation.

Purpose To investigate the impact of macular pigment (MP) on fundus autofluorescence (FAF) lifetimes in vivo by characterizing full-thickness idiopathic macular holes (MH) and macular pseudo-holes (MPH). Methods A total of 37 patients with MH and 52 with MPH were included. Using the fluorescence lifetime imaging ophthalmoscope (FLIO), based on a Heidelberg Engineering Spectralis system, a 30° retinal field was investigated. FAF decays were detected in a short (498–560 nm; ch1) and long (560–720 nm; ch2) wavelength channel. τm, the mean fluorescence lifetime, was calculated from a three-exponential approximation of the FAF decays. Macular coherence tomography scans were recorded, and macular pigment's optical density (MPOD) was measured (one-wavelength reflectometry). Two MH subgroups were analysed according to the presence or absence of an operculum above the MH. A total of 17 healthy fellow eyes were included. A longitudinal FAF decay examination was conducted in nine patients, which were followed up after surgery and showed a closed MH. Results In MH without opercula, significant τm differences (p

Purpose To investigate the interrelationship between the oxygen supply of the retina and its regulation with the severity of primary open-angle glaucoma (POAG). Methods Central retinal artery (CRAE) and vein (CRVE) diameters and oxygen saturation of peripapillary retinal vessels in 41 patients suffering from POAG (64.1 ± 12.9 years) and 40 healthy volunteers (63.6 ± 14.1 years) were measured using the retinal vessel analyzer. All measures were taken before and during flicker light stimulation. The mean retinal nerve fiber layer thickness (RNFLT) was determined by OCT and the visual field mean defect (MD) was identified using perimetry. Results In glaucoma patients, CRAE (r = −0.48 p = 0.002) and CRVE (r = −0.394 p = 0.014) at baseline were inversely related to MD, while arterial and venous oxygen saturation showed no significant dependence on the severity of the damage. However, the flicker light-induced change in arterio-venous difference in oxygen saturation was correlated with the MD (r = 0.358 p = 0.027). The diameters of arteries and veins at baseline decreased with reduction of the mean RNFLT (arteries: r = 0.718 p

Goal: To measure retinal vessel oxygen saturation in rest and under stimulation of neuronal activity by flicker light as well as vascular dilation upon flicker. Methods: 18 patients with non-proliferative diabetic retinopathy (mean age: 62.2±8.3 years), 41 patients with primary open angle glaucoma (64.0+12.8 years) and 40 control subjects (63.6+14 years) were investigated. Vessel diameters (central retinal arterial and venous equivalents – CRAE and CRVE) and oxygen saturation (SO2, dual – wavelength optical oximetry) were determined before and during luminance flicker stimulation (12.5 Hz, modulation depth: 1:20) for 90 s. Results: Flicker light increased CRAE, CRVE, and venous SO2 by 1.42%±3.72%, 2.80%*±2.70%, and 2.03%*±2.43% in diabetic patients as well as 4.98%*±6.23%, 8.94%*±5.26%, and 4.20%*±3.71% in the controls (*: p

PURPOSE To characterize the macular region and to investigate the influence of the macular pigment (MP) on fundus autofluorescence (FAF) lifetimes in vivo. METHODS Forty-eight healthy subjects with a mean age of 24.1 ± 3.6 years (range, 20-37 years) were included. A 30° retinal field was investigated using the fluorescence lifetime imaging ophthalmoscope (FLIO), based on a Heidelberg Engineering Spectralis system, detecting FAF decays in a short (498-560 nm; ch1)- and a long (560-720 nm; ch2)-wavelength channel. The mean fluorescence lifetime τm was calculated from a 3-exponential approximation of the FAF decays. Macular pigment optical density (MPOD) was measured by one-wavelength reflectometry, and macular optical coherence tomogram (OCT) scans were recorded. Correlations between τm and MPOD were analyzed. RESULTS The τm showed shortest values at the macular region with a mean of 82 ps (ch1) and 126 ps (ch2). We found a strong correlation of τm to the MPOD (ch1: r = -0.760; ch2: r = -0.663; P < 0.001), as well as a topologic agreement of shortest τm with highest MPOD. CONCLUSIONS Macular pigment, which is known to have very short fluorescence decays, considerably contributes to the macular autofluorescence (AF). This study gives indirect evidence for a strong impact of MP on macular τm, although no direct measurement of MP autofluorescence lifetimes in vivo is possible at this point. Potentially, imaging the FAF lifetimes could lead to a novel methodology for the detection of macular pigment properties and pathology-induced changes in the living human retina.