Increased ratios of complement factors C3a to C3 in aqueous humor and serum mark glaucoma progression.

INTRODUCTION: We recently performed a combined analysis of publicly available proteomic studies of aqueous humor (AH) of patients with primary open angle glaucoma (POAG). This analysis revealed changes in complement protein concentrations in the AH of progressive POAG patients, which suggested that the complement system may play a role in POAG progression. As the proteomic studies could not provide information on the activity of the complement system, we addressed this question in the current study. METHODS: Blood serum and AH were obtained from 30 patients: 10 progressive POAG, 10 stable POAG and, as controls, 10 cataract patients. Glaucoma patients with a visual field Mean Deviation (MD) change of at least 1.0 dB/year were considered progressive; a MD change of less than 0.5 dB/year was considered stable. The ratio between the levels of complement factors C3a and C3 was used as indicator for activation of the complement cascade. The factors were measured with commercially available ELISA kits. RESULTS: AH levels of complement factors C3 and C3a did not significantly differ between groups. In serum, complement factor C3 did not differ between groups whereas C3a was significantly elevated in progressive POAG patients compared to controls (p < 0.05). The resulting complement C3a/C3 ratio was significantly higher in progressive POAG patients in both AH (p < 0.05) and serum (p < 0.01), and this ratio significantly correlated between the two body fluids (p < 0.001). Furthermore, there was a strong correlation between disease progression and C3a/C3 activation ratio both in AH (p < 0.01) and in serum (p < 0.001). The higher the complement C3a/C3 ratio, the faster the disease progression. CONCLUSION: Significant increases in AH and serum complement C3a/C3 ratios were observed in progressive POAG patients but not in stable POAG patients. Furthermore, the complement C3a/C3 ratio correlated strongly with the rate of disease progression in both AH and serum. These findings suggest that activation of the complement system plays a role in glaucoma progression and that progressive glaucoma patients may have systemic changes in complement activation.

The aqueous humor proteome of primary open angle glaucoma: An extensive review.

BACKGROUND: We reviewed the literature on the aqueous humor (AH) proteome of primary open angle glaucoma (POAG) patients in order to obtain deeper insight into the pathophysiology of POAG. METHODS: We searched Pubmed and Embase up to May 2019 for studies that compared AH protein composition between POAG (cases) and cataract (controls). Untargeted studies (measuring the whole proteome, by LC-MS/MS) were divided into two subgroups depending on the type of surgery during which POAG AH was collected: glaucoma filtration surgery (subgroup 1) or cataract surgery (subgroup 2). We reanalyzed the raw data (subgroup 1) or combined the reported data (subgroup 2) to perform GO enrichment (GOrilla) and pathway analysis (Pathvisio). RESULTS: Out of 93 eligible proteomic studies, seven were untargeted studies that identified 863 AH proteins. We observed 73 differentially expressed proteins in subgroup 1 and 87 differentially expressed proteins in subgroup 2. Both subgroups were characterized by activation of the acute immune response, dysregulation of folate metabolism and dysregulation of the selenium micronutrient network. For subgroup 1 but not for subgroup 2, proteins of the complement system were significantly enriched. CONCLUSION: AH proteome of POAG patients shows strong activation of the immune system. In addition, analysis suggests dysregulation of folate metabolism and dysregulation of selenium as underlying contributors. In view of their glaucoma surgery, POAG patients of subgroup 1 most likely are progressive whereas POAG patients in subgroup 2 most likely have stable POAG. The proteome difference between these subgroups suggests that the complement system plays a role in POAG progression.

The use of optical coherence tomography angiography in comparing choriocapillaris recovery between two treatment strategies for multifocal choroiditis: a pilot clinical trial.

PURPOSE: To compare differences in choriocapillaris flow deficit (CC FD) in multifocal choroiditis (MFC) between two treatment arms using optical coherence tomography angiography (OCTA). METHODS: In this prospective randomized clinical trial, patients were randomized to either Group 1 which received standard tapering dose of oral corticosteroids, or Group 2 which received additional dexamethasone implant (or intravitreal methotrexate). The patients were followed-up until 12 weeks using OCTA and other imaging tools. CC FD and visual acuity between the two groups were compared at each visit. RESULTS: Twenty-five subjects (17 males; 25 eyes) were studied (11 eyes in Group 1). There were no differences between the visual acuity or CC FD (1.12 versus 1.08 mm2; p = 0.86) at baseline between the groups. However, patients in Group 2 achieved better visual acuity (0.32 ± 0.23 versus 0.15 ± 0.11; p = 0.025) and CC FD (0.54 versus 0.15 mm2; p = 0.008) at 12 weeks. CONCLUSIONS: OCTA is a useful tool in monitoring the CC FD recovery after treatment in MFC. Patients receiving intravitreal corticosteroid/methotrexate in addition to systemic corticosteroid showed greater resolution of CC FD on OCTA compared to those receiving only oral corticosteroids.

Blood biomarkers for assessment of mitochondrial dysfunction: An expert review.

Although mitochondrial dysfunction is the known cause of primary mitochondrial disease, mitochondrial dysfunction is often difficult to measure and prove, especially when biopsies of affected tissue are not available. In order to identify blood biomarkers of mitochondrial dysfunction, we reviewed studies that measured blood biomarkers in genetically, clinically or biochemically confirmed primary mitochondrial disease patients. In this way, we were certain that there was an underlying mitochondrial dysfunction which could validate the biomarker. We found biomarkers of three classes: 1) functional markers measured in blood cells, 2) biochemical markers of serum/plasma and 3) DNA markers. While none of the reviewed single biomarkers may perfectly reveal all underlying mitochondrial dysfunction, combining biomarkers that cover different aspects of mitochondrial impairment probably is a good strategy. This biomarker panel may assist in the diagnosis of primary mitochondrial disease patients. As mitochondrial dysfunction may also play a significant role in the pathophysiology of multifactorial disorders such as Alzheimer's disease and glaucoma, the panel may serve to assess mitochondrial dysfunction in complex multifactorial diseases as well and enable selection of patients who could benefit from therapies targeting mitochondria.

Retinal Microvascular Alterations in Patients with Quiescent Posterior and Panuveitis Using Optical Coherence Tomography Angiography.

PURPOSE: To quantify retinochoroidal vascular parameters using swept-source optical coherence tomography (SS-OCTA) in quiescent posterior and panuveitis. METHODS: In this cross-sectional study, subjects with quiescent posterior and panuveitis underwent fundus imaging using SS-OCTA (DRI Triton®, Topcon, Japan). The metrics calculated were fractal dimension (FD), foveal avascular zone (FAZ) area, retinal vascularity index (capillary density index-CDI), and choroidal vascularity index (CVI). RESULTS: We included 38 eyes of 20 patients, 9 males aged 34.7 ± 10.5 years, 30 eyes of 30 age- and gender-matched healthy controls, 10 females aged 33.6 ± 8.5 years. Comparing patients with controls, we found a lower FD (p < .001), larger FAZ (p > .001), lower CDI in the superficial plexus (p = .019), and lower CVI (p < .001). We also found lower retinal and choroidal and thicknesses (p < .001 and p = .025, respectively). CONCLUSIONS: Patients with quiescent posterior and panuveitis have a significantly reduced retinochoroidal vascular density compared to healthy control subjects.

Early Visual Functional Outcomes and Morphological Responses to Anti-Vascular Growth Factor Therapy in Diabetic Macular Oedema Using Optical Coherence Tomography Angiography.

PURPOSE: Diabetic macular oedema (DME) is a vision-threatening complication of diabetic retinopathy. Spectral domain optical coherence tomography angiography (OCTA) is useful for assessing DME. We performed serial OCTA measurements before and after 3 monthly intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections to understand its relationship with best corrected visual acuity (BCVA), central macular thickness (CMT) and vascular indices. METHODS: OCTA assessment consisting of 6 × 6 mm scans centred on fovea and en-face retinal angiograms were obtained. Scans were done at baseline and at 1 month following each of the 3 intravitreal injections of anti-VEGF (ranibizumab, Lucentis®). RESULTS: Our prospective study included 24 eyes of 24 subjects, aged 63.0 ± 5.0 years. There was a mean gain of 0.07 LogMAR (3 letters) and reduction of CMT, vessel density (VD) and perfusion density (PD) by end of 3rd month. CMT was independently associated with improvement in BCVA. There were significant reductions in FAZ area, VD and PD over 3 months from baseline. CONCLUSION: At three months, intravitreal anti-VEGF therapy is associated with visual function recovery in DME, with reduction in CMT being the most reliable predictor of response. OCTA shows a reduction in VD and PD respectively suggestive of reduced macular perfusion in the short term. Simultaneous reduction in FAZ size can be due to reversal of manual displacement of the retinal capillaries resulting from resolution of intraretinal oedema.

Optical Coherence Tomography Findings of Underlying Choroidal Neovascularization in Punctate Inner Choroidopathy.

Purpose: To analyze findings on optical coherence tomography (OCT) suggestive of choroidal neovascularization (CNV) in lesions of punctate inner choroidopathy (PIC). Methods: In this multi-center retrospective study, clinical data of patients with PIC were retrospectively analyzed. Quantitative data (height, width, and volume of PIC lesions), and qualitative data (disruption of ellipsoid zone (EZ)/Bruch's membrane (BM), outer retinal fuzziness, and choroidal back-shadowing) were compared between CNV+ and CNV- groups using Mann-Whitney U-test and Fischer's exact test. Results: In total, 35 eyes (29 patients; 21 women; mean age: 33.3 ± 6.5 years) were selected for analysis. Of the 35 PIC lesions studied, 17 had underlying CNV. Lesions with CNV+ had larger height, width, and volume (p < 0.001) and several distinctive features, such as disruption of EZ and BM, outer retinal fuzziness, and hypo-reflective back-shadowing (p < 0.001) compared with CNV-lesions. Conclusions: Quantitative and qualitative OCT analysis can aid in the prediction of an underlying CNV in the eyes with PIC.

Fasting and post-oral-glucose-load levels of methylglyoxal are associated with microvascular, but not macrovascular, disease in individuals with and without (pre)diabetes: The Maastricht Study.

AIMS: Reactive dicarbonyl compounds, such as methylglyoxal (MGO), rise during an oral glucose tolerance test (OGTT), particularly in (pre)diabetes. Fasting MGO levels are associated with chronic kidney disease (CKD) and cardiovascular disease (CVD) in patients with poorly controlled type 2 diabetes mellitus (T2DM). Yet, whether fasting or post-OGTT plasma MGO levels are associated with vascular disease in people with (pre)diabetes is unknown. METHODS: Subjects with normal glucose metabolism (n=1796; age: 57.9±8.2 years; 43.3% men), prediabetes (n=478; age: 61.6±7.6 years; 54.0% men) and T2DM (n=669; age: 63.0±7.5 years; 67.0% men) from the Maastricht Study underwent OGTTs. Plasma MGO levels were measured at baseline and 2h after OGTT by mass spectrometry. Prior CVD was established via questionnaire. CKD was reflected by estimated glomerular filtration rate (eGFR) and albuminuria; retinopathy was assessed using retinal photographs. Data were analyzed using logistic regression adjusted for gender, age, smoking, systolic blood pressure, total-to-HDL cholesterol ratio, triglycerides, HbA1c, BMI and medication use. Odd ratios (ORs) were expressed per standard deviation of LN-transformed MGO. RESULTS: Fasting and post-OGTT MGO levels were associated with higher ORs for albuminuria ≥30mg/24h [fasting: 1.12 (95% CI: 0.97-1.29); post-OGTT: 1.19 (1.01-1.41)], eGFR<60mL/min/1.73 m2 [fasting: 1.58 (95% CI: 1.38-1.82), post-OGTT: 1.57 (1.34-1.83)] and retinopathy [fasting: 1.59 (95% CI: 1.01-2.53), post-OGTT: 1.38 (0.77-2.48)]. No associations with prior CVD were found. CONCLUSION: Fasting and post-OGTT MGO levels were associated with microvascular disease, but not prior CVD. Thus, therapeutic strategies directed at lowering MGO levels may prevent microvascular disease.

Need for manual segmentation in optical coherence tomography angiography of neovascular age-related macular degeneration.

PURPOSE: To compare the characteristics of eyes that had manual vs. automated segmentation of choroidal neovascular membrane (CNVM) using optical coherence tomography angiography (OCTA). METHODS: All patients with CNVM underwent OCTA using the Zeiss Angioplex Cirrus 5000. Slabs of the avascular outer retina, outer retina to choriocapillaris (ORCC) region and choriocapillaris were generated. Manual segmentation was done when there were significant segmentation artifacts. Presence of activity of CNVM was adjudged by the presence of subretinal fluid (SRF) on structural OCT and was compared to activity detected on en face OCTA slabs based on well-defined criteria. RESULTS: Eighty-one eyes of 81 patients were recruited of which manual segmentation was required in 46 (57%). Eyes with automated segmentation had significantly more CNVM in the ORCC (75%) whereas those with manual segmentation had deeper CNVM (sub-RPE = 22%, intra-PED = 22%) (p<0.001). Twenty eyes (25%) were found to have active CNVM on both the structural OCT and OCTA while an additional 19 eyes were presumed to have active CNVM on OCTA alone. There was only modest concordance between disease activity detected using structural OCT and OCTA (Kappa = 0.47, 95% CI = 0.30 to 0.64). CONCLUSIONS: Manual segmentation of OCTA is required in more than 50% eyes with CNVM and this progressively increases with increasing depth of CNVM location from the ORCC to below the RPE. There is moderate concordance between OCTA and structural OCT in determining CNVM activity.

Aqueous humor proteome of primary open angle glaucoma: A combined dataset of mass spectrometry studies.

Analysis of the proteins of the aqueous humor can help to elucidate the complex pathogenesis of primary open angle glaucoma. Thanks to advances in liquid chromatography tandem mass spectrometry (LC-MS/MS) it is now possible to identify hundreds of proteins in individual aqueous humor samples without the need to pool samples. We performed a systematic literature search to find publications that performed LC-MS/MS on aqueous humor samples of glaucoma patients and of non-glaucomatous controls. Of the seven publications that we found, we obtained the raw data of three publications. These three studies used glaucoma patients that were clinically similar (i.e. undergoing glaucoma filtration surgery) which prompted us to reanalyse and combine their data. Raw data of each study were analysed separately with the latest version of MaxQuant (version v1.6.11.0). Outcome files were exported to Microsoft Excel. Samples belonging to the same patient were averaged to obtain peptide expression values per individual. We compared the overlap of identified proteins using the VLOOKUP function of Excel and a publicly available Venn diagram software. For the peptide sequences that can belong to multiple proteins (usually of the same protein family), we initially included all possibly identified proteins. This ensured that we would not miss a potential overlap between the studies due to differences in identified peptide counts. Next, of those peptides of which we compared multiple proteins, only one unique protein was included in our analysis i.e. either the protein overlapping between studies or in case of no overlap, the protein that had the highest identified peptide count. This yielded 639 unique proteins detected in aqueous humor of either glaucoma patients or non-glaucomatous controls. In our manuscript entitled "The aqueous humor proteome of primary open angle glaucoma: An extensive review" [1], we further analysed this dataset. The dataset was exported to Perseus (version 1.6.5.0). We removed contaminants and filtered for proteins detected with high confidence, i.e. in more than 70% of the samples of at least one study. This yielded 248 proteins of which we compared the expression in glaucoma patients against control patients. Gene ontology enrichment analysis and pathway analysis was used to interpret the results. The unfiltered dataset reported in this data article and the approach reported here to reanalyse and combine raw data of different studies can be applied by other glaucoma researchers to gain more insight in the pathogenesis of glaucoma.

Knowledge base and preferred methods of obtaining knowledge of glaucoma patients.

PURPOSE: To gather information regarding patient's understanding of glaucoma and the manner in which patients wish to learn about the disease with the intent of improving patient education. METHODS: Forty-four of sixty randomly selected ophthalmologists (73%) asked four of their patients consecutively to complete a questionnaire about glaucoma. The selection of questions was based on focus group interviews and suggestions from several experts. Topics included knowledge about glaucoma and its treatment, the need for information, and preferred providers and methods of patient education. RESULTS: Fifty percent of the patients had 49% or less correct answers to questions about glaucoma or its treatment. Per item the correct answers ranged from 5% to 90%. Lack of knowledge was associated with low level of education, short duration of glaucoma, high age, and no preference for the Internet as method of supplying information. These variables, however, did not identify groups with a considerable lack of knowledge sufficiently accurately to target patient education. A high need for information was observed and included information about the patient's own glaucoma. Almost all patients preferred the ophthalmologist and many also a nurse or a representative of the Glaucoma Patient Society as providers of information. Written material was the preferred method. CONCLUSIONS: Patient education should address all patients. A patient education program should cover a wide range of topics with a focus on general information through written material and information tailored to the individual glaucoma patient's needs. The ophthalmologist is a key- person, but others could play an important role in patient education.

The relationship between visual field loss in glaucoma and health-related quality-of-life.

PURPOSE: to investigate the relationship between visual field loss and health-related quality-of-life (HRQOL) in patients with ocular hypertension (OHT) or primary open-angle glaucoma (POAG). METHODS: we conducted a cross-sectional study among 537 OHT and POAG patients from seven hospitals in The Netherlands. Clinical information was obtained from medical files. Patients completed a questionnaire, containing generic HRQOL instruments (EQ-5D and Health Utilities Index mark 3), vision-specific National Eye Institute Visual Functioning Questionnaire (VFQ-25), and glaucoma-specific Glaucoma Quality-of-Life questionnaire (GQL-15). The impact of visual field loss on HRQOL scores was analysed with multiple linear regression analyses. RESULTS: a relationship between mean deviation (MD) and HRQOL was found after adjusting for age, gender, visual acuity, medication side effects, laser trabeculoplasty, and glaucoma surgery. We found interaction between MD in both eyes for GQL and VFQ-25 scores. The relationship between MD and utility was non-linear, with utility only affected at MD-values below -25 dB in the better eye. Visual acuity, side effects, and glaucoma surgery independently affected HRQOL. Binocular MD and MD in the better eye had similar impacts on HRQOL, whereas MD in the worse eye had an independent effect. HRQOL was affected more by binocular defects in the inferior than in the superior hemifield. CONCLUSION: visual field loss in progressing glaucoma is independently associated with a loss in both disease-specific and generic quality-of-life. It is important to prevent progression, both in early and in advanced glaucoma, especially in patients with inferior hemifield defects and severe defects in either eye.

Patient ignorance is the main reason for treatment delay in primary rhegmatogenous retinal detachment in The Netherlands.

AIMS: Treatment delay of progressive vision-threatening conditions should be minimal. In this study, the treatment delay of patients with a rhegmatogenous retinal detachment (RRD) undergoing retinal detachment surgery was quantified, and causes for this delay were evaluated. MATERIALS AND METHODS: Consecutive patients (n=205) presenting with a primary RRD between June 2006 and June 2007 at the tertiary referral center (TRC) were interviewed. Five categories of delay were discerned in the following: 'patient delay,' 'general practitioner's delay,' 'referring ophthalmologist's delay,' 'delay at the TRC' and 'delay before surgery at the TRC'. In addition, overall delay was calculated. RESULTS: In total, 186 eyes were included in the analysis. Median overall delay between the patients' first symptoms and RRD surgery was 10 days. Almost 60% of this overall delay time was due to patient delay and the delay of the general practitioner. More than 50% of patients had a delay owing to unawareness of the symptoms. The median patient delay was significantly lower in patients with a vitreous hemorrhage and in patients with a history of a RRD in the fellow eye. CONCLUSIONS: The major reason for patient delay with a RDD was the patients' unawareness and unfamiliarity with the symptoms of a retinal detachment.

Cost-effectiveness of early detection and treatment of ocular hypertension and primary open-angle glaucoma by the ophthalmologist.

PURPOSE: To determine the most cost-effective case-finding strategy for the ophthalmologist to detect and treat ocular hypertension (OH) and primary open-angle glaucoma (POAG) at an early stage to prevent blindness. DESIGN: A Markov cost-effectiveness simulation model. METHODS: Three case-finding strategies are analysed and compared. The simulated cohort consists of all initial patients of at least 40 years old visiting an ophthalmic practice. All patients undergo ophthalmoscopy, but tonometry is routinely performed to: (1) all initial patients, (2) high-risk patients only, or (3) no one. The population characteristics are based on data of 1000 initial patients. Transition probabilities are taken from the literature. The (direct) costs of diagnosis and treatment represent those for the Netherlands. The time-horizon of the model is 20 years. An annual discount rate of 4% is used. MAIN OUTCOME MEASURES: Costs, proportion of patients becoming blind, years of blindness. RESULTS: The costliest strategy (1) leads to least blindness. The incremental cost-effectiveness ratio, which shows extra costs per year of vision saved in comparison to the cheapest strategy (3), is lower for strategy (1) than for strategy (2). It amounts to euro1707, not including extra costs due to blindness (eg associated with the use of disability facilities). When such costs exceed euro1707 per patient per year, which is most likely, then strategy (1) becomes cost saving. CONCLUSION: It is most cost-effective to routinely perform tonometry to all initial ophthalmic patients to prevent blindness due to glaucoma.