European Glaucoma Society Terminology and Guidelines for Glaucoma, 4th Edition - Chapter 2: Classification and terminologySupported by the EGS Foundation: Part 1: Foreword; Introduction; Glossary; Chapter 2 Classification and Terminology

Transitions of the Understanding and Definition of Primary Glaucoma

Objective:

In previous decades, glaucoma has been primarily attributed to elevated intraocular pressure (IOP), but this has gradually been replaced by the development of optic neuropathy as the central concept of glaucoma in developed countries. However, there still remain strong controversies in the definition of glaucoma in China. In this current review, we are going to discuss these controversies and elaborate on the historical transitions of the definition of glaucoma both in China and developed countries. Furthermore, we will briefly describe the “ocular-cranial pressure gradient” theory and discuss the relationship between glaucoma and degenerative diseases of the central nervous system (CNS) in order to show the complex pathogenesis of glaucoma and the importance for the modification to the definition of glaucoma.

Data Sources:

We performed a comprehensive search in both PubMed and SinoMed using the following keywords: (a) “primary glaucoma” and “guideline,” (b) “ocular-cranial pressure gradient,” and (c) “glaucoma,” “Alzheimer's disease,” and “Parkinson's disease.” The literature search included the related articles with no restrictions on publication date.

Study Selection:

The primary references were Chinese and English articles including (a) original guidelines and expert consensuses of primary glaucoma, (b) reviews focusing on the differences between various versions of these guidelines and consensuses, and (c) papers about ocular-cranial pressure gradient theory and the relationship between glaucoma and CNS degenerative diseases.

Results:

The definitions and classifications of both primary open-angle glaucoma and primary angle-closure glaucoma differ between Chinese glaucoma consensuses and international primary glaucoma guidelines. Chinese definitions and classifications put more emphasis on the IOP, while international guidelines put more emphasis on the presence of optic neuropathy. The ocular-cranial pressure gradient theory and the research on the relationship between glaucoma and CNS degenerative diseases have provided new directions for exploring the pathogenesis of glaucoma.

Conclusions:

As regards the definition and classification of primary glaucoma, we find that there are still some discrepancies between Chinese expert consensuses and international guidelines. Glaucoma is a disease with complex etiologies, while its common characteristic is a specific optic neuropathy. The current definition and understanding of glaucoma is an ongoing and evolving process, reflecting our latest available evidence on its pathogenesis. Chinese ophthalmology community may need to update our guidelines, accommodating these latest developments.

Autoantibody Biomarker Discovery in Primary Open Angle Glaucoma Using Serological Proteome Analysis (SERPA)

Glaucoma is an optic neurological disorder and the leading cause of irreversible blindness worldwide, with primary open angle glaucoma (POAG) as its most prevalent form. An early diagnosis of the disease is crucial to prevent loss of vision. Mechanisms behind glaucoma pathogenesis are not completely understood, but disease related alterations in the serological autoantibody profile indicate an immunologic component. These changes in immunoreactivity may serve as potential biomarkers for glaucoma diagnostics. We aimed to identify novel disease related autoantibodies targeting antigens in the trabecular meshwork as biomarkers to support early detection of POAG. We used serological proteome analysis (SERPA) for initial autoantibody profiling in a discovery sample set. The identified autoantibodies were validated by protein microarray analysis in a larger cohort with 60 POAG patients and 45 control subjects. In this study, we discovered CALD1, PGAM1, and VDAC2 as new biomarker candidates. With the use of artificial neural networks, the panel of these candidates and the already known markers HSPD1 and VIM was able to classify subjects into POAG patients and non-glaucomatous controls with a sensitivity of 81% and a specificity of 93%. These results suggest the benefit of these potential autoantibody biomarkers for utilization in glaucoma diagnostics.

Using Kalman Filtering to Forecast Disease Trajectory for Patients With Normal Tension Glaucoma

PURPOSE

To determine whether a machine learning technique called Kalman filtering (KF) can accurately forecast future values of mean deviation (MD), pattern standard deviation, and intraocular pressure for patients with normal tension glaucoma (NTG).

DESIGN

Development and testing of a forecasting model for glaucoma progression.

METHODS

We parameterized and validated a KF (KF-NTG) to forecast MD, pattern standard deviation, and intraocular pressure at 24 months into the future using 263 eyes of 263 Japanese patients with NTG. We determined the proportion of patients with MD forecasts within 0.5, 1.0, and 2.5 dBs of the actual values and calculated the root mean squared error (RMSE) for each forecast. We compared KF-NTG with a previously published KF model calibrated using patients with high-tension open-angle glaucoma (KF-HTG) and to 3 conventional forecasting algorithms.

RESULTS

The 263 patients with NTG had mean ± standard deviation age of 63.4 ± 10.5 years. KF-NTG forecasted MD values 24 months ahead within 0.5, 1.0, and 2.5 dBs of the actual value for 78 eyes (32.2%), 122 eyes (50.4%), and 211 eyes (87.2%), respectively. The proportion of eyes with MD values forecasted within 2.5 dB of the actual value for the KF-NTG (87.2%) were similar to KF-HTG (86.0%) and the null model (86.4%), and much better than the 2 linear regression-based models (72.7-74.0%; P < .001). When forecasting MD, KF-NTG (RMSE = 2.71) and KF-HTG (RMSE = 2.68) achieved lower RMSE than the other 3 forecasting models (RMSE = 2.81-3.90), indicating better performance.

CONCLUSION

As observed previously for patients with HTG, KF can also effectively forecast disease trajectory for many patients with NTG.

Prevalence of glaucoma in the Northern Finland Birth Cohort Eye Study

PURPOSE

To report the prevalence of glaucoma in the Northern Finland Birth Cohort (NFBC) Eye Study.

METHODS

Subjects of the population-based Northern Finland 1966 Birth Cohort (NFBC), aged 45-49 years at the time of the field examination, were randomized to eye screening (50%) and control (50%) groups. The eye examination protocol included best corrected visual acuity (BCVA), measurements of intraocular pressure and central corneal thickness, Humphrey 24-2 perimetry, stereoscopic optic nerve head (ONH) and retinal nerve fibre layer (RNFL) photography and imaging with optical coherence tomography (OCT), scanning laser polarimetry (GDx) and scanning laser ophthalmoscopy (HRT). The diagnosis of glaucoma was made by two independent general ophthalmologists and three independent glaucoma experts based on the evaluation of the ONH and RNFL photographs and the visual fields.

RESULTS

Totally, 10 321 subjects of the NFBC main study were alive in Finland in 2011, and they were randomized to the NFBC Eye Study group (n = 5155) and the control group (n = 5166). Of the randomized subjects, 3039 of 5155 (59%) responded and had sufficient data for the study. Glaucoma was suspected in 172 subjects (5.7%) at the first phase of the evaluation protocol. The interobserver agreement between two screening ophthalmologists was moderately good (kappa value 0.54 [95% confidence intervals (CI) 0.46-0.61]). Finally, definite glaucoma was found in 33 subjects (1.1% [95% CI 0.8-1.5]).

CONCLUSION

The study provides up-to-date information on the prevalence of glaucoma in a middle-aged Caucasian population in Finland. The baseline data reported here allows the evaluation of the cost-effectiveness of screening later on.

Development of a new algorithm based on FDT Matrix perimetry and SD-OCT to improve early glaucoma detection in primary care

Purpose

The purpose of this study was to develop an objective algorithm to discriminate the earliest stages of glaucoma using frequency doubling technology (FDT) Matrix perimetry and spectral domain-optical coherence tomography (OCT) technology to improve primary care detection.

Materials and methods

Three hundred six eyes (mean age 58.67±15.12) from 161 patients were included and classified in the following three groups: 101 nonglaucoma (GI-NG), 100 glaucoma suspect (GII-SG), and 105 open-angle glaucoma (GIII-OAG). All participants underwent a visual field exploration using the Humphrey Matrix visual field instrument and retinal nerve fiber layer evaluation using the Topcon 3D OCT-2000. Pattern deviation plot was divided into 19 areas and five aggrupation or quadrants and ranked with a value between 0 and 4 according to its likelihood of normality, and differences among three groups were analyzed. Principal component analysis (PCA) was also used to extract the most notable features of FDT and OCT, and a logistic regression analysis was applied to obtain the classification rules.

Results

Only area numbers 7 and 12 and the central zone of FDT Matrix showed statistical differences (P<0.05) between GI-NG and GII-SG. The classification rules were estimated by the four PCA obtained from FDT Matrix and 3D OCT-2000 in a separate and combined use. Area under the receiver operating characteristic curve was 78.88% with FDT-PCA, 82.09% with OCT-PCA, and 94.27% with combined use of FDT and OCT-PCA to discriminate GI-NG and GII-SG.

Conclusion

The predictive rules based on FDT-PCA or OCT-PCA provide a high sensitivity and specificity to detect the earliest stages of glaucoma and even better in combined use. These predictive rules may help the future development of software for FDT Matrix perimetry and 3D OCT-2000, which will greatly improve their diagnostic ability, making them useful in daily practice in a primary care setting.

Better tolerance of preservative-free latanoprost compared to preserved glaucoma eye drops: the 12-month real-life FREE study

Background

Lack of efficacy due to bad compliance caused by intolerance issues is the main reason for a change to a better tolerated ocular treatment, such as using preservative-free (PF) eye drops.

Aim

To assess the efficacy and local tolerance after 12 months and patient satisfaction regarding local treatment tolerance and handling at inclusion and after 6 months of PF latanoprost compared to preserved glaucoma eye drops.

Methods

This was an international, prospective, and observational real-life study. Up to three visits, one at inclusion and two follow-up visits (one after 6 and one after 12 months) were planned. Efficacy, local tolerance, and patient satisfaction were the main evaluation criteria.

Results

Data from 721 patients were available for the statistical analysis. Overall, 64.8% (467/721) of patients switched treatment before inclusion: 62.2% in the preserved and 68.9% in the PF latanoprost group. IOP values were similar between PF latanoprost and preserved eye drops and remained stable at all visits. Ocular signs and symptoms improved after switching to PF latanoprost; the prevalence of conjunctival hyperemia was significantly lower (P=0.0015) at both follow-up visits. At follow-up visit 1, 49.5% of the patients who switched to PF latanoprost decreased or stopped the use of artificial tears. Satisfaction regarding tolerance in patients using PF latanoprost improved significantly after the switch from preserved eye drops to PF latanoprost (88.9% and 42.5%, respectively, P<0.0001).

Conclusion

This first real-life study showed that PF latanoprost was as efficacious but better tolerated than preserved eye drops over a sustained period of 12 months, while providing a significantly higher patient satisfaction and potentially allowing improvement in the patient’s daily life.

Safety of high-dose intravitreal triamcinolone acetonide as low-cost alternative to anti-vascular endothelial growth factor agents in lower-middle-income countries

Purpose

The purpose of this study was to evaluate the safety of high-dose intravitreal triamcinolone acetonide (IVTA) as affordable low-cost alternative to anti-vascular endothelial growth factor (anti-vascular endothelial growth factor [anti-VEGF] agents) in lower-middle-income countries.

Patients and methods

This was a retrospective interventional non-comparative case series. The study recruited patients who received 20 mg IVTA for treating various retinal and optic nerve diseases over the past 5 years. Main outcome measure was assessment of complications secondary to high-dose IVTA. The crosstabs procedure was used to display the interaction between the variables tested. The ANOVA test was used to analyze the differences among group means.

Results

The study included 207 eyes of 168 patients. The main indication for high-dose IVTA were diabetic macular edema 64%, and macular edema secondary to retinal vein occlusion 19%. The mean follow-up period post-injection was 22 months. Mean number of injections was 1.3. Cataract developed in 54% of eyes. Glaucoma developed in 18.5% of eyes. Glaucoma surgery for intractable glaucoma attributed to high-dose IVTA was needed in 1% of eyes. Endophthalmitis and retinal detachment developed in one patient each.

Conclusion

High-dose IVTA is a safe and cost-effective alternative to anti-VEGF agents. Cataract formation and intraocular pressure rise do not pose major adverse effects when weighed against the risk of vision loss due to inability to afford anti-VEGF treatment.

Comparison of variation of intraocular pressure in noncontact tonometry in patients subjected to phacoemulsification and trabeculectomy with phacoemulsification

OBJECTIVE

Evaluate the pattern of intraocular pressure (IOP) variations through the pneumatic tonometer, between two specific surgical techniques, and the possible variables that may influence the behavior of this pressure.

METHODS

Retrospective cross-sectional study carried out through the review of electronic medical records of a private ophthalmological reference hospital in the city of Goiânia, Goiás, Brazil, from 2012 to 2016, comprising of a sample of 550 eyes. The analyzed variables were, age, gender, IOP, axis, pachymetry, anterior chamber depth, and axial length.

RESULTS

In the end, the study consisted of 231 eyes, represented by 179 patients. Of these, 182 eyes were operated on by isolated cataract surgery, with a mean age of 72.0±9.5 years. The combined surgery represented a total of 49 eyes, 34 patients with a mean age of 71.9±8.14 years. There was statistical significance (P<0.05) in correlating the pre- and postoperative IOP values in the 24-hour, 7-, 15-day, and 12-month postoperative periods.

CONCLUSION

A standard of variation of IOP was found through the pneumatic tonometer in both surgical techniques, but a more significant reduction was observed in combined surgery than in isolated cataract surgery, and further studies with a greater epidemiological impact are required for confirmation of this conclusion.

Clinical effectiveness of the Manchester Glaucoma Enhanced Referral Scheme

Background

Glaucoma referral filtering schemes have operated in the UK for many years. However, there is a paucity of data on the false-negative (FN) rate. This study evaluated the clinical effectiveness of the Manchester Glaucoma Enhanced Referral Scheme (GERS), estimating both the false-positive (FP) and FN rates.

Method

Outcome data were collected for patients newly referred through GERS and assessed in ‘usual-care’ clinics to determine the FP rate (referred patients subsequently discharged at their first visit). For the FN rate, glaucoma suspects deemed not requiring referral following GERS assessment were invited to attend for a ‘reference standard’ examination including all elements of assessment recommended by National Institute for Health and Care Excellence (NICE) by a glaucoma specialist optometrist. A separate 33 cases comprising randomly selected referred and non-referred cases were reviewed independently by two glaucoma specialist consultant ophthalmologists to validate the reference standard assessment.

Results

1404 patients were evaluated in GERS during the study period; 651 (46.3%) were referred to the Hospital Eye Service (HES) and 753 (53.6%) were discharged. The FP rate in 307 assessable patients referred to the HES was 15.5%. This study reviewed 131 (17.4%) of those patients not referred to the HES through the GERS scheme; 117 (89.3%) were confirmed as not requiring hospital follow-up; 14 (10.7%) required follow-up, including 5 (3.8%) offered treatment. Only one patient (0.8%) in this sample met the GERS referral criteria and was not referred (true FN). There were no cases of missed glaucoma or non-glaucomatous pathology identified within our sample.

Conclusion

The Manchester GERS is an effective glaucoma filtering scheme with a low FP and FN rate.

Spectral Domain Optical Coherence Tomography Assessment of Macular and Optic Nerve Alterations in Patients with Glaucoma and Correlation with Visual Field Index

Introduction

To evaluate the sectorial thickness of single retinal layers and optic nerve using spectral domain optic coherence tomography (SD-OCT) and highlight the parameters with the best diagnostic accuracy in distinguishing between normal and glaucoma subjects at different stages of the disease.

Material and Methods

For this cross-sectional study, 25 glaucomatous (49 eyes) and 18 age-matched healthy subjects (35 eyes) underwent a complete ophthalmologic examination including visual field testing. Sectorial thickness values of each retinal layer and of the optic nerve were measured using SD-OCT Glaucoma Module Premium Edition (GMPE) software. Each parameter was compared between the groups, and the layers and sectors with the best area under the receiver operating characteristic curve (AUC) were identified. Correlation of visual field index with the most relevant structural parameters was also evaluated.

Results and Discussion

All subjects were grouped according to stage as follows: Controls (CTRL); Early Stage Group (EG) (Stage 1 + Stage 2); Advanced Stage Group (AG) (Stage 3 + Stage 4 + Stage 5). mGCL TI, mGCL TO, mIPL TO, mean mGCL, cpRNFLt NS, and cpRNFLt TI showed the best results in terms of AUC according classification proposed by Swets (0.9 < AUC < 1.0). These parameters also showed significantly different values among group when CTRL vs EG, CTRL vs AG, and EG vs AG were compared. SD-OCT examination showed significant sectorial thickness differences in most of the macular layers when glaucomatous patients at different stages of the disease were compared each other and to the controls.

Structural Reversal of Disc Cupping After Trabeculectomy Alters Bruch Membrane Opening-Based Parameters to Assess Neuroretinal Rim

OBJECTIVE

To assess the impact of trabeculectomy for glaucoma on morphometric neuroretinal parameters of the optic nerve head (ONH) using spectral-domain optical coherence tomography (SD-OCT).

DESIGN

Retrospective, interventional case series.

METHODS

Participants: Eighty-eight eyes of 88 patients who underwent trabeculectomy with mitomycin C in 2016.

INTERVENTION

All patients underwent trabeculectomy in 1 eye (study eye) and had evaluable SD-OCT examinations of the ONH to measure neuroretinal tissue before and at least at 1 of the 3-, 6-, and 12-month follow-up time points after surgery.

MAIN OUTCOME MEASURES

Longitudinal change in Bruch membrane opening minimum rim width (BMO-MRW), Bruch membrane opening minimum rim area (BMO-MRA), peripapillary retinal nerve fiber layer (RNFL) thickness, intraocular pressure (IOP), and mean deviation in perimetry.

RESULTS

In study eyes, BMO-MRW significantly increased postsurgically comparing baseline and follow-up examinations at 3 months (P = .012), at 6 months (P = .007), and at 1 year (P = .010) after trabeculectomy. The increase in BMO-MRW 6 months after surgery correlated with IOP reduction (r = 0.48; P = .001). BMO-MRA showed an equal increase (P ≤ .034). RNFL thickness remained stable between baseline and follow-up at 3, 6, and 12 months and showed a moderate loss after 18 months (P = .021) of follow-up.

CONCLUSIONS

Structural reversal of disc cupping after trabeculectomy markedly influences Bruch membrane opening-based parameters for up to more than 1 year. Improvement in morphometry seems to correlate with the reduction of IOP while visual field function appears not to be influenced. In longitudinal follow-up of glaucoma patients by SD-OCT, evaluation of BMO-based parameters necessitates to reflect bias caused by surgery.

Association between serotonin-norepinephrine reuptake inhibitors and acute angle closure: What is known?

Serotonin-norepinephrine reuptake inhibitors are widely used antidepressants with a relatively safe profile. One of the complications associated with this group of drugs is acute angle closure. The mechanisms linking serotonin-norepinephrine reuptake inhibitors and acute angle closure are complex and may be interlinked with the effects of the drug on the inhibition of serotonin and noradrenaline reuptake, as well as pseudo-anticholinergic effects, dopaminergic effects, and idiosyncratic reactions with the drug molecule in the eye. Individual characteristics, such as polymorphisms of the gene encoding the 2D6 subunit of cytochrome P450, may affect the metabolism of the serotonin-norepinephrine reuptake inhibitor, whereas the combination with other drugs may lead to an increased risk of iridocorneal angle closure and may further exacerbate other mechanisms. Improved knowledge of the mechanisms linking serotonin-norepinephrine reuptake inhibitors and acute angle closure and of the risk factors predisposing to patients to acute angle closure will reduce the number of patients affected by this dangerous complication.

Intravitreal S100B Injection Leads to Progressive Glaucoma Like Damage in Retina and Optic Nerve

The glial protein S100B, which belongs to a calcium binding protein family, is up-regulated in neurological diseases, like multiple sclerosis or glaucoma. In previous studies, S100B immunization led to retinal ganglion cell (RGC) loss in an experimental autoimmune glaucoma (EAG) model. Now, the direct degenerative impact of S100B on the retina and optic nerve was evaluated. Therefore, 2 μl of S100B was intravitreally injected in two concentrations (0.2 and 0.5 μg/μl). At day 3, 14 and 21, retinal neurons, such as RGCs, amacrine and bipolar cells, as well as apoptotic mechanisms were analyzed. Furthermore, neurofilaments, myelin fibers and axons of optic nerves were evaluated. In addition, retinal function and immunoglobulin G (IgG) level in the serum were measured. At day 3, RGCs were unaffected in the S100B groups, when compared to the PBS group. Later, at days 14 and 21, the RGC number as well as the β-III tubulin protein level was reduced in the S100B groups. Only at day 14, active apoptotic mechanisms were noted. The number of amacrine cells was first affected at day 21, while the bipolar cell amount remained comparable to the PBS group. Also, the optic nerve neurofilament structure was damaged from day 3 on. At day 14, numerous swollen axons were observed. The intraocular injection of S100B is a new model for a glaucoma like degeneration. Although the application site was the eye, the optic nerve degenerated first, already at day 3. From day 14 on, retinal damage and loss of function was noted. The RGCs in the middle part of the retina were first affected. At day 21, the damage expanded and RGCs had degenerated in all areas of the retina as well as amacrine cells. Furthermore, elevated IgG levels in the serum were measured at day 21, which could be a sign of a late and S100B independet immune response. In summary, S100B had a direct destroying impact on the axons of the optic nerve. The damage of the retinal cell bodies seems to be a consequence of this axon loss.

The short-term effect of acupuncture on different ocular blood flow parameters in patients with primary open-angle glaucoma: a randomized, clinical study

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.

The Association of Socioeconomic Status with Severity of Glaucoma and the Impacts of Both Factors on the Costs of Glaucoma Medications: A Cross-Sectional Study in West Bengal, India

PURPOSE

To evaluate the association of socioeconomic status (SES) with severity of glaucoma and assess the impacts of both SES and disease-severity factors on the costs of glaucoma medications among different glaucoma subtypes in West Bengal, India.

METHODS

This cross-sectional study (2014-16) followed the treatment of 304 primary glaucoma patients for at least 18 months. The visual field based glaucoma staging was followed for stages 0-3; patients with field of vision <10° were categorized as stage 4 (end stage). We checked only the mean cost of glaucoma medications per patient and not "direct costs." The individuals' monthly incomes were classified into: low, moderate, and higher SES.

RESULTS

Urban residence (odds ratio [OR] 0.6, P < 0.009), higher SES (OR 0.3, P < 0.001), and higher awareness (nearly 50%, P < 0.007) significantly lowered the odds of having end-stage glaucoma. Sixty-nine percent primary angle-closure glaucoma (PACG) and 79% juvenile open-angle glaucoma (JOAG) belonged to low SES, forming the bulk of end-stage glaucoma. Overall medical cost from stage 0 to advanced stage in all subtypes rises except in primary open-angle glaucoma (POAG). Only 28% eyes from low SES were treated with branded drugs in early disease and that too declined to 16% in stage 4, while 57% higher SES used branded medications in early disease stage. Expenditure as a percent of income was the highest in JOAG (16%) followed by PACG (15%) and POAG (14%) among low SES.

CONCLUSIONS

Results indicate SES influences on disease outcome, the clinical management, and the glaucoma medication expenses in West Bengal. Medical costs of glaucoma increase with worsening disease severity; greater use of generic drugs does not always ensure direct cost savings.

Peptides of the variable IgG domain as potential biomarker candidates in primary open-angle glaucoma (POAG)

Autoantibody profiling has gained increasing interest in the research field of glaucoma promising the detection of highly specific and sensitive marker candidates for future diagnostic purposes. Recent studies demonstrated that immune responses are characterized by the expression of congruent or similar complementarity determining regions (CDR) in different individuals and could be used as molecular targets in biomarker discovery. Main objective of this study was to characterize glaucoma-specific peptides from the variable region of sera-derived immunoglobulins using liquid chromatography--mass spectrometry (LC-MS)-based quantitative proteomics. IgG was purified from sera of 13 primary open-angle glaucoma patients (POAG) and 15 controls (CTRL) and subsequently digested into Fab and Fc by papain. Fab was further purified, tryptic digested and measured by LC-MS/MS. Discovery proteomics revealed in total 75 peptides of the variable IgG domain showing significant glaucoma-related level changes (P < 0.05; log2 fold change ≥ 0.5): 6 peptides were high abundant in POAG sera, whereas 69 peptides were low abundant in comparison to CTRL group. Via accurate inclusion mass screening strategy 28 IgG V domain peptides were further validated showing significantly decreased expression levels in POAG sera. Amongst others 5 CDR1, 2 CDR2 and 1 CDR3 sequences. In addition, we observed significant shifts in the variable heavy chain family distribution and disturbed κ/λ ratios in POAG patients in contrast to CTRL. These findings strongly indicate that glaucoma is accompanied by systemic effects on antibody production and B cell maturation possibly offering new prospects for future diagnostic or therapy purposes.

Retinal thickness correlates with parietal cortical atrophy in early-onset Alzheimer's disease and controls

Introduction

The retina may reflect Alzheimer's disease (AD) neuropathological changes and is easily visualized with optical coherence tomography (OCT). Retinal thickness decrease has been correlated to AD, however, without information on amyloid status. We correlated retinal (layer) thickness to AD biomarkers in amyloid-positive early-onset AD (EOAD) patients and amyloid-negative controls.

Methods

We measured macular thickness and peripapillary retinal nerve fiber layer thickness with OCT in 15 EOAD patients and 15 controls and correlated retinal thickness to visual rating scores for atrophy on magnetic resonance imaging.

Results

Total macular thickness correlated to parietal cortical atrophy in both groups (Spearman ρ -0.603, P = .001). Macular and peripapillary retinal nerve fiber layer thicknesses were not significantly decreased in EOAD compared to controls.

Discussion

Retinal thickness does not discriminate EOAD from controls but is correlated to parietal cortical atrophy in both groups. These findings may suggest reflection of cerebral cortical changes in the retina, independent of amyloid.

Tenascins in Retinal and Optic Nerve Neurodegeneration

Tenascins represent key constituents of the extracellular matrix (ECM) with major impact on central nervous system (CNS) development. In this regard, several studies indicate that they play a crucial role in axonal growth and guidance, synaptogenesis and boundary formation. These functions are not only important during development, but also for regeneration under several pathological conditions. Additionally, tenascin-C (Tnc) represents a key modulator of the immune system and inflammatory processes. In the present review article, we focus on the function of Tnc and tenascin-R (Tnr) in the diseased CNS, specifically after retinal and optic nerve damage and degeneration. We summarize the current view on both tenascins in diseases such as glaucoma, retinal ischemia, age-related macular degeneration (AMD) or diabetic retinopathy. In this context, we discuss their expression profile, possible functional relevance, remodeling of the interacting matrisome and tenascin receptors, especially under pathological conditions.