Originalbeiträge (Originals). Altered microvascular density in patients with anorexia nervosa ­ an optical coherence tomography angiography (OCTA) pilot study.

OBJECTIVES: To investigate macular and peripapillary vascular density (VD) in patients with anorexia nervosa (AN) compared to healthy controls. Methods:Whole face scans of the superficial and deep macular layers and whole face and peripapillary scans of the radial peripapillary capillaries (RPC) were obtained using optical coherence tomography angiography (OCTA, AngioVueR, Optovue) in ten patients with AN and ten age-matched controls.The primary objective was to determine whether there was a difference between the vessel density (VD) in the above areas in AN and controls. P-values ≤ 0.0125 were considered statistically significant. Results: VD in the superficialmacular en-face OCTA image was significantly lower in the study group compared to the control group. Neither the deepmacula nor the radial peripapillary capillary (RPC) in the whole-face image nor the RPC-peripapillary imaging appeared to be significantly different. Conclusion: Patients with AN showed reduced VD in the superficialmacular layers compared to healthy controls, which can be discussed as a consequence of the malnutrition. OCTA could be a useful non- invasive tool to detect reduced peripheral blood supply to show vascular changes that occur before ocular symptoms.

Bilateral Upper Eyelid Swelling with Abscess under Treatment with Etanercept. / Bilaterale Oberlidschwellung mit Abszedierung unter Etanercept-Therapie.

We report the case of a 66-year-old female patient with rheumatoid arthritis and bilateral upper eyelid abscess under treatment with etanercept. Because bilateral upper lid abscesses due to a systemic cause are rare and cases of abscess formation under treatment with etanercept have been described in the literature, we discuss a possible connection between the bilateral upper lid abscess and the existing immunosuppressive medication.

Optimizing intraocular lens power calculation using adjusted conventional keratometry for cataract surgery combined with Descemet membrane endothelial keratoplasty.

PURPOSE: To evaluate the utility of intraocular lens (IOL) power calculation using adjusted conventional keratometry (K) according to postoperative posterior to preoperative anterior corneal curvature radii (PPPA) ratio for eyes with Fuch's dystrophy undergoing cataract surgery combined with Descemet membrane endothelial keratoplasty (triple DMEK). METHODS: A fictitious refractive index (FRI) was determined (Pentacam HR®) based on the PPPA ratio in 50 eyes undergoing triple DMEK. Adjusted corneal power was calculated in every eye using adjusted K values: K values determined by the IOLMaster were converted to adjusted anterior corneal radius using the mean FRI. Posterior corneal radius was calculated using the mean PPPA ratio. Adjusted corneal power was determined based on the calculated corneal radii and thick lens formula. Refractive errors calculated using the Haigis, SRK/T, and HofferQ formulae based on the adjusted corneal power were compared with those based on conventional K measurements. RESULTS: Calculated PPPA ratio and FRI were 0.801 and 1.3271. Mean prediction error based on conventional K was in the hyperopic direction (Haigis: 0.84D; SRK/T: 0.74D; HofferQ: 0.74D) and significantly higher (P < 0.001) than that based on adjusted corneal power (0.18D, 0.22D, and 15D, respectively). When calculated according to adjusted corneal power, the percentage of eyes with a hyperopic shift > 0.5D fell significantly from 64 to 30% (Haigis), 62 to 36% (SRK/T), and 58 to 26% (HofferQ), respectively. CONCLUSION: IOL power calculation based on adjusted corneal power can be used to reduce the risk of a hyperopic shift after triple DMEK and provides a more accurate refractive outcome than IOL power calculation using conventional K.

Assessing the validity of corneal power estimation using conventional keratometry for intraocular lens power calculation in eyes with Fuch's dystrophy undergoing Descemet membrane endothelial keratoplasty.

PURPOSE: The present retrospective study was designed to test the hypothesis that the postoperative posterior to preoperative anterior corneal curvature radii (PPPA) ratio in eyes with Fuch's dystrophy undergoing Descemet membrane endothelial keratoplasty (DMEK) is significantly different to the posterior to anterior corneal curvature radii (PA) ratio in virgin eyes and therefore renders conventional keratometry (K) and the corneal power derived by it invalid for intraocular lens (IOL) power calculation. METHODS: Measurement of corneal parameters was performed using Scheimpflug imaging (Pentacam HR, Oculus, Germany). In 125 eyes with Fuch's dystrophy undergoing DMEK, a fictitious keratometer index was calculated based on the PPPA ratio. The preoperative and postoperative keratometer indices and PA ratios were also determined. Results were compared to those obtained in a control group consisting of 125 eyes without corneal pathologies. Calculated mean ratios and keratometer indices were then used to convert the anterior corneal radius in each eye before DMEK to postoperative posterior and total corneal power. To assess the most appropriate ratio and keratometer index, predicted and measured powers were compared using Bland-Altman plots. RESULTS: The PPPA ratio determined in eyes with Fuch's dystrophy undergoing DMEK was significantly different (P < 0.001) to the PA ratio in eyes without corneal pathologies. Using the mean PA ratio (0.822) and keratometer index (1.3283), calculated with the control group data to convert the anterior corneal radius before DMEK to power, leads to a significant (P < 0.001) underestimation of postoperative posterior negative corneal power (mean difference (∆ = - 0.14D ± 0.30) and overestimation of total corneal power (∆ = - 0.45D ± 1.08). The lowest prediction errors were found using the geometric mean PPPA ratio (0.806) and corresponding keratometer index (1.3273) to predict the postoperative posterior (∆ = - 0.01 ± 0.30) and total corneal powers (∆ = - 0.32D ± 1.08). CONCLUSIONS: Corneal power estimation using conventional K for IOL power calculation is invalid in eyes with Fuch's dystrophy undergoing DMEK. To avoid an overestimation of corneal power and minimize the risk of a postoperative hyperopic shift, conventional K for IOL power calculation should be adjusted in eyes with Fuch's dystrophy undergoing cataract surgery combined with DMEK. The fictitious PPPA ratio and keratometer index may guide further IOL power calculation methods to achieve this.

Ocular perfusion in patients with reduced left ventricular ejection fraction measured by optical coherence tomography angiography.

AIMS: The aim of this study is to evaluate retinal and optic nerve head (ONH) perfusion in patients with systolic chronic heart failure (CHF) compared to healthy control subjects. METHODS: Twenty-seven eyes of 27 patients with CHF (study group) and 31 eyes of 31 healthy subjects (control group) were prospectively included in this study. CHF Patients had a left ventricular ejection fraction (LVEF) < 50% and were classified by New York Heart Association (NYHA) class. OCT-A was performed using RTVue XR Avanti with AngioVue (Optovue, Inc, Fremont, CA, USA). The area of the foveal avascular zone (FAZ) and flow density (FD) data were extracted and analyzed. RESULTS: There was no significant difference in the signal strength index between the study group (group 1) and the control group (group 2) (ONH: p = 0.015; macula: p = 0.703). The difference in the area of the foveal avascular zone between the two groups was also not significant (p = 0.726). The flow density (whole en face) in the ONH (RPC) in group 1 was significantly lower compared to control (group 1 = 48.40 ± 2.48 (49.0 [46.7, 50.3]); group 2 = 50.15 ± 1.85 (50.6 [48.5, 51.70]); p = 0.008). There was a significant and strong correlation between LVEF and the macular flow density (whole en face) (superficial: rs = 0.605 deep: rs = 0.425, p < 0.01). CONCLUSIONS: Patients with CHF showed reduced flow density compared with healthy controls. The reduced FD correlated with the LVEF and the functional (NYHA) class. Retinal perfusion as measured using OCTA might provide an insight into the global microperfusion and hemodynamic state of heart failure patients.

CILIORETINAL ARTERIES INFLUENCE OPTIC NERVE HEAD, PERIPAPILLARY, AND MACULAR VESSEL DENSITIES IN HEALTHY EYES: An Optical Coherence Tomography Angiography Study.

BACKGROUND/PURPOSE: To analyze the influence of a cilioretinal artery (CRA) on macular and peripapillary vessel density in healthy eyes as measured using optical coherence tomography angiography. METHODS: A total of 83 eyes of 83 patients were included in this study. Optical coherence tomography angiography was performed using the RTVue XR Avanti with AngioVue (Optovue Inc). The macula was imaged with a 3 × 3-mm scan, whereas for the optic nerve head a 4.5 × 4.5-mm scan was taken. Optical coherence tomography angiography images of the optic nerve head were screened for the presence of a CRA. RESULTS: In 31 eyes, a CRA was detected (37.3%). The vessel density in eyes with a CRA was significantly lower within the optic nerve head (P = 0.005) but higher in the peripapillary capillary network (P < 0.001) and (whole en face) macular superficial capillary plexus (P = 0.025), when compared with eyes with no CRA. CONCLUSION: Our findings reveal that in eyes with a CRA, the vessel density in the peripapillary and macular superficial capillary plexus is increased, whereas the optic nerve head perfusion (as indicated by vessel density in the inside disk region) is decreased. This has to be considered when analyzing quantitative optical coherence tomography angiography parameters in scientific and clinical applications.

ALTERED RETINAL PERFUSION IN PATIENTS WITH INACTIVE GRAVES OPHTHALMOPATHY USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

Objective: The aim of this study was to evaluate retinal and optic nerve head (ONH) perfusion in patients with inactive Graves ophthalmopathy (GO) and compare it to healthy controls using optical coherence tomography angiography (OCTA). Methods: Twenty-nine eyes of 29 patients with inactive GO (study group) and 29 eyes of 29 healthy subjects (control group) were included in this study. The vessel density (VD) data in the superficial and deep retinal OCT angiogram of the macula and the radial peripapillary capillary network (RPC) were extracted and analyzed. OCTA was performed using RTVue XR Avanti with AngioVue (Optovue Inc, Fremont, CA). Clinical activity was evaluated using the clinical activity score, the severity assessment using the NOSPECS classification. Results: The VD in the superficial OCT angiogram and in the OCT angiogram of the ONH was significantly lower in the GO group when compared to the control group (whole en face, P = .016; parafovea, P = .026; RPC peripapillary, P = .027). There was no significant correlation between VD and functional parameters or the NOSPECS classification. Conclusion: Macular VD and ONH capillary density measured using OCTA were significantly lower in the study group compared to healthy controls. Noninvasive quantitative analysis of retinal perfusion using OCTA could be useful in monitoring patients with GO. Abbreviations: CAS = clinical activity score; GO = Graves ophthalmopathy; OCTA = optical coherence tomography angiography; ONH = optic nerve head; RPC = radial peripapillary capillary; rSp = Spearman's correlation coefficient; VD = vessel density.

Using the posterior to anterior corneal curvature radii ratio to minimize the risk of a postoperative hyperopic shift after Descemet membrane endothelial keratoplasty.

PURPOSE: To evaluate different corneal parameters in identifying patients at risk of a hyperopic shift after (DMEK). METHODS: This retrospective study included 92 eyes of patients with FECD after DMEK surgery. Pachymetry parameters, various tomographic parameters and densitometry values before and after DMEK were determined using a rotating Scheimpflug system (Pentacam HR, Oculus). For assessing the posterior to anterior corneal curvature relationship, we calculated the RPA (posterior to anterior corneal curvature radii ratio). RESULTS: The average keratometry reading of the posterior corneal surface (KmB) increased and the total corneal refractive power (TCRP) decreased significantly after surgery (P < .001). There was a significant difference between the preoperative and postoperative RPA (P < .001) and the posterior Q value (P < .001). The strongest correlation was found between the change in the KmB and the preoperative RPA (Spearman's correlation coefficient = 0.872, P < .001). In the receiver operating characteristic (ROC) analysis, the highest AUC values (for ∆KmB) among the different preoperative parameters tested were obtained for RPA and posterior Q value (Asph. QB) with AUROC (area under the ROC) values of 0.95 and 0.89, respectively. CONCLUSIONS: The Q value and the RPA showed the highest correlation with the change in corneal refractive power and the greatest AUC. These parameters could be used as surrogate markers to identify eyes that might be at risk of a greater postoperative hyperopic shift, which would allow more accurate setting of refractive goals.

Optical coherence tomography angiography-derived flow density: a review of the influencing factors.

Research interest in the possibility of quantifying macular and optic nerve head perfusion through optical coherence tomography angiography (OCTA) is rapidly advancing. Numerous scientific trials have furthered our understanding of the capabilities and the limitations of this novel technology, while applying OCTA to various ocular pathologies. In recent years, different parameters such as age, gender, intraocular pressure, spherical equivalent, physical activity, systemic diseases, and medication have been shown to have a significant impact on quantitative OCTA metrics. Since OCTA is likely to remain a "hot topic" in the near future, it is crucial to be aware of influencing factors in order to ensure correct interpretation of imaging results. This article reviews the factors currently known to influence flow density (FD) as measured by OCTA in healthy eyes.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY IN PATIENTS WITH RETINITIS PIGMENTOSA.

PURPOSE: To evaluate the correlation between the flow density measured by optical coherence tomography angiography and functional parameters in patients with retinitis pigmentosa. METHODS: Twenty eyes of 20 patients with retinitis pigmentosa and 21 eyes of 21 healthy subjects were prospectively included in this study. Optical coherence tomography angiography was performed using RTVue XR Avanti with AngioVue (Optovue Inc). The macula was imaged with a 6 × 6-mm scan, whereas for the optic nerve head a 4.5 × 4.5-mm scan was taken. Visual acuity, visual field parameters (mean deviation and visual field index), full-field electroretinography, and multifocal electroretinography were tested for correlation with flow density data. RESULTS: The flow density (whole en face) in the superficial/deep retinal OCT angiograms and in the optical coherence tomography angiography of the optic nerve head was significantly lower in the retinitis pigmentosa group when compared with the control group (P < 0.001). The flow density in the superficial retinal OCT angiogram (fovea) correlated significantly with the visual acuity (rSpearman = -0.77, P < 0.001) and the visual field parameters (visual field index: rSpearman = 0.56, P = 0.01; mean deviation: rSpearman = 0.54, P = 0.01). CONCLUSION: Patients with retinitis pigmentosa show a decreased macular and optic nerve head perfusion compared with healthy subjects. The flow density measured using optical coherence tomography angiography correlated with subjective and objective functional parameters.

[Value of Optical Coherence Tomography Angiography in Neuroophthalmology]. / Stellenwert der optischen Kohärenztomografie-Angiografie bei neuroophthalmologischen Erkrankungen.

Within the last few years, optical coherence tomography angiography (OCTA) has been one of the most intensively investigated developments in ophthalmic research. As a non-invasive imaging tool, it can visualise retinal, choroidal and peripapillary blood flow and was first introduced in retinology. Recently, OCTA has received increasing attention in neuro-ophthalmological diagnostic testing. Special consideration has been given to diseases in which vascular pathogenesis is discussed, such as non-arteritic and arteritic anterior ischemic optic neuropathy (NAION and AAION). Numerous studies have demonstrated rarefication of the peripapillary vascular network and reduced blood flow in NAION and AAION patients compared to healthy patients. The extent of the vascular damage correlates with the severity of optic atrophy. Similar findings also apply to optic atrophy from other causes (e.g., optic nerve head drusen, hereditary optic neuropathy, etc.). However, the exact causal relationships between optic neuropathy and blood flow reduction remain unclear and must be addressed in future investigations. In some diseases, OCTA also seems to be of differential diagnostic value. In haemangioblastomas, it has provided relevant information, especially in large and broad-based findings, and may represent the haemangioblastoma-typical vascular networks and the afferent vessels. This review summarises new information from OCTA studies on neuro-ophthalmic diseases, and questions their relevance and value in clinical use. In the future, it can be expected that OCTA will provide standard values through longitudinal studies with larger numbers of cases that more relevant changes in blood flow in a wide variety of clinical pictures will be analysed more profoundly and will possibly contribute to differential diagnostic and therapeutic studies.

[Treatment Options for Adenoid Cystic Lacrimal Gland Carcinoma - A Case Series and Literature Review]. / Therapieoptionen bei adenoidzystischem Tränendrüsenkarzinom ­ Fallserie und aktueller Literaturüberblick.

Adenoid cystic carcinoma of the lacrimal gland (ACC) is a rare malignant orbital tumour with a poor overall prognosis. Current therapeutic approaches like radical and local surgery, adjuvant radiation and neoadjuvant intra-arterial chemotherapy are controversial. We present three cases of patients with ACC with different therapy concepts and discuss these with current recommendations from the literature.

[Expression of Motion Artifacts in OCT-Angiography Imaging in Healthy Subjects Using Two Different Devices]. / Vergleich der Bildqualität zweier unterschiedlicher OCT-Angiografie-Systeme mit Fokus auf Bewegungsartefakten bei gesunden Probanden.

BACKGROUND: To compare the expression of motion artifacts in optical coherence tomography angiography (OCT-A) in healthy subjects using two different devices. METHODS: In this study, 25 eyes of 25 healthy volunteers with no history of any ocular disease or ocular surgery were included. OCT-A imaging was performed using the RTVue XR Avanti (Optovue Inc., Fremont, California, USA) and the Spectralis OCT-A (Heidelberg Engineering, Heidelberg, Deutschland). The macula was imaged twice in each proband with active eye tracking (ET) using a 3 × 3 mm2 or a 10 × 10° scan, respectively. The expression of motion artifact was analyzed by two independent readers in the superficial OCT-angiogram using the Motion Artifact Score (MAS). RESULTS: The signal strength index (SSI) was 73.0 ± 7.8 (Optovue) and 39.6 ± 3.6 (Heidelberg), which is equivalent to 73.0% (Optovue SSImax = 100 = 100%) and 79.2% (SSImax = 50 = 100%) of the maximum quality score. Both devices showed a very good image quality (mean MAS Optovue: 1.32 ± 0.551, mean MAS Heidelberg: 1.7 ± 0.789, p = 0.006). Of all measurements, quilting/banding was found in 20% of Optovue patients (10/50) and 6% of Heidelberg patients (3/50). Stretching was found in 4% of Optovue patients (2/50) and in 6% of Heidelberg patients (3/50). Vessel doubling was only seen in one Optovue angiogram (2%) as well as a displacement (2%). Blink lines only existed in three Heidelberg angiograms (6%). CONCLUSION: Despite different software and hardware approaches, both devices were able to take high-quality images with a very low prevalence of motion artifacts. Nevertheless, these artifacts still also occur in healthy subjects with good fixation. With regards to MAS, there was a high agreement between the two readers. However, the analysis of artifacts remains complex and requires experience as well as a precise assessment in evaluating OCT-A images.

Feasibility of optical coherence tomography angiography to assess changes in retinal microcirculation in ovine haemorrhagic shock.

BACKGROUND: This study aimed to investigate the feasibility of optical coherence tomography angiography (OCT-A) for quantitative analysis of flow density to assess changes in retinal perfusion in an experimental model of haemorrhagic shock. METHODS: Haemorrhagic shock was induced in five healthy, anaesthetized sheep by stepwise blood withdrawal of 3 × 10 ml∙kg- 1 body weight. OCT-A imaging of retinal perfusion was performed using an OCT device. Incident dark-field illumination microscopy videos were obtained for the evaluation of conjunctival microcirculation. Haemodynamic variables and flow density data in the OCT angiogram were analysed before and during progressive haemorrhage resulting in haemorrhagic shock as well as after fluid resuscitation with 10 ml∙kg- 1 body weight of balanced hydroxyethyl starch solution (6% HES 130/0.4). Videos of the conjunctival microcirculation were recorded at baseline, in haemorrhagic shock, and after resuscitation. Data are presented as median with interquartile range. Comparisons between time points were made using Friedman's test and the degree of correlation between two variables was expressed as Spearman's rank correlation coefficient. RESULTS: Mean arterial pressure and cardiac index (CI) decreased and lactate concentration increased after induction of shock, and haemodynamics recovered after resuscitation. The flow density in the superficial retinal OCT angiogram decreased significantly after shock induction (baseline 44.7% (40.3; 50.5) vs haemorrhagic shock 34.5% (32.8; 40.4); P = 0.027) and recovered after fluid resuscitation (46.9% (41.7; 50.7) vs haemorrhagic shock; P = 0.027). The proportion of perfused vessels of the conjunctival microcirculation showed similar changes. The flow density measured using OCT-A correlated with the conjunctival microcirculation (perfused vessel density: Spearman's rank correlation coefficient ρ = 0.750, P = 0.001) and haemodynamic parameters (CI: ρ = 0.693, P < 0.001). CONCLUSIONS: Retinal flow density, measured using OCT-A, significantly decreased in shock and recovered after fluid therapy in an experimental model of haemorrhagic shock. OCT-A is feasible to assess changes in retinal perfusion in haemorrhagic shock and fluid resuscitation.

Quantitative changes in flow density in patients with adult-onset foveomacular vitelliform dystrophy: an OCT angiography study.

PURPOSE: To quantitatively compare the flow density, the retinal thickness, and the area of the foveal avascular zone (FAZ) between patients with adult-onset foveomacular vitelliform dystrophy (AOFVD) and a healthy controls. METHODS: Thirteen eyes (eight patients) with AOFVD and 13 matched eyes (13 patients) without any ocular pathology were included in this study. A 6 × 6 mm optical coherence tomography angiography (OCTA) scan was performed for every included eye. The flow density (superficial retinal vascular layer, deep retinal vascular layer and choriocapillary layer), retinal thickness and FAZ (superficial retinal vascular layer and deep retinal vascular layer) were subsequently analyzed. RESULTS: The mean flow density was decreased in the AOFVD patients in all measured vascular layers. The difference from the control group was statistically significant in the parafoveal sector of the deep retinal vascular layer (P = 0.02), and a clear trend was found in the superficial retinal vascular layer (P = 0.05). Both groups had comparable FAZs in the superficial and deep retinal vascular layers. The retinal thickness values were higher in the fovea (P = 0.840) and lower in the parafoveal sectors (P = 0.125). The difference was significant in the superior parafoveal sector (P = 0.034). CONCLUSIONS: Flow densities as measured by OCTA are decreased in the superficial retinal vascular layer and the deep retinal vascular layer in patients with AOFVD. These findings could be helpful for diagnosing and understanding the pathogenesis of this disease.

Correlation of flow density, as measured using optical coherence tomography angiography, with structural and functional parameters in glaucoma patients.

PURPOSE: To evaluate the correlation between flow density, as measured by optical coherence tomography angiography (OCTA), and structural and functional parameters in patients with open-angle glaucoma. METHODS: Thirty-four eyes of 34 patients with open-angle glaucoma and 35 eyes of 35 healthy subjects were prospectively included in this study. OCTA was performed using RTVue XR Avanti with AngioVue. The macula was imaged with a 3 × 3 mm scan and the optic nerve head (ONH) with a 4.5 × 4.5 mm scan. Visual field parameters [mean deviation (MD), pattern standard deviation (PSD) and visual field index (VFI)], Bruch's membrane opening minimal rim width (BMO-MRW), retinal nerve fiber layer thickness (RNFLT) and the stereometric parameters rim area, cup/disc area (HRT III, Heidelberg Retina Tomograph, Heidelberg Engineering) were tested for correlation with flow density data. RESULTS: The flow density (whole en face) in the retinal OCT angiograms (superficial: p = 0.01; deep: p = 0.005), in the radial peripapillary capillary network (p < 0.001) and in the OCT angiograms of the optic nerve head (p = 0.004) were significantly lower in the glaucoma group when compared with the control group. The flow density in the RPC network correlated significantly with all functional and structural parameters tested. The strongest correlation was found between the RPC flow density (inside disc) and the BMO-MRW (Spearman's correlation coefficient = 0.912, p < 0.001). CONCLUSIONS: Glaucoma patients showed a reduced ONH and macular perfusion when compared with healthy controls. The flow density as measured by OCTA correlated with structural damage and visual field loss in glaucoma patients. Non-invasive quantitative analyses of flow density using OCTA provide a new parameter describing a different aspect of glaucoma, which could be useful in clinical practice.

Quantification of macular perfusion using optical coherence tomography angiography: repeatability and impact of an eye-tracking system.

BACKGROUND: The aim of the study was to evaluate the impact of integration of the eye-tracking system (ET) on the repeatability of flow density measurements using optical coherence tomography (OCT) angiography. METHODS: 20 healthy subjects were included in this study. OCT-angiography was performed using RTVue XR Avanti (Optovue Inc., Fremont, California, USA). The macula was imaged using a 3 × 3 mm scan twice with and twice without activation of the ET. Flow density data of the macular in the superficial and deep OCT angiograms were extracted and analyzed. RESULTS: The difference between the flow density (whole en face) in the first session and second session with and without ET was statistically non-significant (with ET: superficial retinal OCT angiogram: p = 0.50; deep retinal OCT angiogram: p = 0.89; without ET: superficial retinal OCT angiogram: p = 0.81; deep retinal OCT angiogram: p = 0.24). There was no significant difference in the coefficients of repeatability for measurements with and without ET in the superficial retinal OCT angiogram (adjusted p-value = 0.176), whereas the difference was significant for the deep retinal OCT angiogram (adjusted p-value = 0.008). CONCLUSIONS: Integration of the ET improved the repeatability of flow density measurements in the deep OCT angiogram; this needs to be considered when evaluating the long-term changes of flow density and when comparing data of different studies and different devices.

Conjunctival repair after glaucoma drainage device exposure using collagen-glycosaminoglycane matrices.

BACKGROUND: To report the results of the repair of conjunctival erosions resulting from glaucoma drainage device surgery using collagen-glycosaminoglycane matrices (CGM). METHODS: Case series of 8 patients who underwent revision surgery due to conjunctival defects with exposed tubes through necrosis of the overlying scleral flap and conjunctiva after Baerveldt drainage device surgery. The defects were repaired by lateral displacement of the tube towards the sclera, with a slice of a CGM as a patch, covered by adjacent conjunctiva. RESULT: Successful, lasting closure (follow-up of 12 to 42 months) of the conjunctival defects was achieved without any side-effects or complications in all eight cases. CONCLUSIONS: Erosion of the drainage tube, creating buttonholes in the conjunctiva after implantation of glaucoma drainage devices, is a potentially serious problem. It can be managed successfully using a biodegradable CGM as a patch.

Quantitative analysis of retinal perfusion in mice using optical coherence tomography angiography.

PURPOSE: To evaluate repeatability of the quantitative analysis of vessel density in the retinas of healthy mice using optical coherence tomography angiography (OCT-A). METHODS: Seventeen eyes of seventeen healthy mice aged 10-15 weeks (young) and 75-95 weeks (old) were included in this study. OCT-A was performed using RTVue XR Avanti (Optovue Inc., Fremont, California, USA) under general anaesthesia. The retina was imaged twice using a 3 × 3 mm2 scan. Retinal thickness and flow density data in the superficial and deep retinal OCT angiograms were extracted and analysed. RESULTS: The differences between the flow density values (whole en face) in the first and second sessions were non-significant (superficial retinal OCT angiogram: first session: 45.4 ± 4.1% (39.1-55.3%); second session: 46.1 ± 4.7% (39.1-59.1%); p = 0.14; deep retinal OCT angiogram: first session: 47.1 ± 3.8% (39.4-53.4%); second session: 47.3 ± 3.7% (39.4-53.8%); p = 0.50). The repeatability assessment of retinal thickness yielded intraclass correlation coefficient (ICC) values ranging between (0.86-0.99) while the ICCs for the flow density measurements ranged from 0.87 to 0.92 for the superficial retinal OCT angiogram and 0.68 to 0.93 for the deep retinal OCT angiogram. CONCLUSIONS: Repeated OCT-A measurement of mice retinal vessel density (VD) revealed valid repeatability, indicating that this non-invasive technology is sufficient for longitudinal assessment of vascular changes in various mouse models and thereby opening the way to in-depth, experimental analysis of the vascular aspects of different retinal diseases and monitoring of disease progression and the effects of treatments.

Descemet membrane endothelial keratoplasty (DMEK) early stage graft failure in eyes with preexisting glaucoma.

PURPOSE: To evaluate the effect of a preexisting glaucoma on the early postoperative outcome of a descemet membrane endothelial keratoplasty (DMEK). METHODS: All patients who underwent DMEK surgery at the Department of Ophthalmology of the University of Muenster with a follow-up of at least 3 months (90d) were included in this study. The best corrected distance visual acuity (BCDVA), the intraocular pressure (IOD), the rate of re-keratoplasty and the rebubbling rate were inter alia recorded. The results of patients with (group 1) and without a preexisting glaucoma (group 2) were compared. RESULTS: 74 eyes of 59 patients with a mean follow-up of 152 ± 70 days were included. 65 eyes were in group 1 and 9 eyes in group 2. The BCDVA significantly improved in both groups after surgery (p < 0.03). The Re-keratoplasty rate (p = 0.172), the number of rebubblings per patient (p = 0.571) and the rebubbling rate (p = 0.939) were not significantly different in patients without glaucoma compared to patients with a preexisting glaucoma. CONCLUSIONS: In the early stage outcome of DMEK no significant impact of a preexisting glaucoma was found.