Dimensions of Arachnoid Bulk Ratio: A Superior Optic Nerve Sheath Index for Intracranial Pressure.

Background Discrepancies in the literature regarding optimal optic nerve sheath diameter (ONSD) cutoffs for intracranial pressure (ICP) necessitate alternative neuroimaging parameters to improve clinical management. Purpose To evaluate the diagnostic accuracy of the dimensions of the perineural subarachnoid space to the optic nerve sheath ratio, measured using US, in predicting increased ICP. Materials and Methods In a prospective cohort study from April 2022 to December 2023, patients with suspected increased ICP underwent optic nerve US to determine the dimensions of arachnoid bulk (DAB) ratio and ONSD before invasive ICP measurement. Correlation between the parameters and ICP, as well as diagnostic accuracy, was assessed using area under the receiver operating characteristic curve (AUC) analysis. Results A total of 30 participants were included (mean age, 39 years ± 14 [SD]; 24 female). The DAB ratio and ONSD were significantly larger in participants with increased ICP (38% [0.16 of 0.42] and 14% [0.82 of 6.04 mm], respectively; P < .001). The DAB ratio showed a stronger correlation with ICP than ONSD (rs = 0.87 [P < .001] vs rs = 0.61 [P < .001]). The DAB ratio and ONSD optimal cutoffs for increased ICP were 0.5 and 6.5 mm, respectively, and the ratio had higher sensitivity (100% vs 92%) and specificity (94% vs 83%) compared with ONSD. Moreover, the DAB ratio better predicted increased ICP than ONSD, with a higher AUC (0.98 [95% CI: 0.95, 1.00] vs 0.86 [95% CI: 0.71, 0.95], P = .047). Conclusion An imaging ratio was proposed to predict ICP based on the relative anatomy of the cerebrospinal fluid space, demonstrating more accurate diagnosis of increased ICP and a strong correlation with ICP values, suggesting its potential utility as a neuroimaging marker in clinical settings. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Shepherd in this issue.

Artificial intelligence for glaucoma: state of the art and future perspectives.

PURPOSE OF REVIEW: To address the current role of artificial intelligence (AI) in the field of glaucoma. RECENT FINDINGS: Current deep learning (DL) models concerning glaucoma diagnosis have shown consistently improving diagnostic capabilities, primarily based on color fundus photography and optical coherence tomography, but also with multimodal strategies. Recent models have also suggested that AI may be helpful in detecting and estimating visual field progression from different input data. Moreover, with the emergence of newer DL architectures and synthetic data, challenges such as model generalizability and explainability have begun to be tackled. SUMMARY: While some challenges remain before AI is routinely employed in clinical practice, new research has expanded the range in which it can be used in the context of glaucoma management and underlined the relevance of this research avenue.

Cataract surgery and IOP: a systematic review of randomised controlled trials.

PURPOSE: Cataract and glaucoma are two of the most common ocular comorbidities. Cataract surgery has been shown to influence intra-ocular pressure (IOP) in patients with glaucoma; nevertheless, the extent of this effect remains controversial, especially in patients with open-angle glaucoma (OAG). The aim of this review is to determine the real effect of cataract surgery on IOP change in patients with OAG, focusing on data retrieved from randomised controlled trials (RCTs). METHODS: A systematic review was performed, including six different RCTs that studied the net effect of cataract surgery on IOP. Eligibility criteria required a full washout from hypotensive therapy, allowing accurate measurement of unmedicated IOP, both before and after surgery. RESULTS: Included studies revealed a consistent reduction on IOP occurring after surgery, varying between 4.1 and 8.5 mmHg depending on the RCT. There was also a decrease in the number of glaucoma medications, with a mean reduction of 0.2-1.0 agents postoperatively. Evaluation of adverse outcomes of cataract surgery showed a very favourable safety profile. CONCLUSION: Although the role of cataract surgery in the algorithm of glaucoma treatment remains to be established, this review highlights a consistent decrease on IOP following surgery and a reduced dependency on glaucoma medications. Potential downgrade in medication can thus be considered in well-controlled glaucoma patients after phacoemulsification. PROSPERO registry: CRD42022343378.

Impact of laser iridotomy on headache symptoms in angle-closure subjects.

BACKGROUND: Migraine symptoms are frequently referred by glaucoma patients. Although most studies analyze headache in the acute setting of angle closure, many patients with chronic occludable angles also complain of headaches. The aim of this study was to determine the impact of laser peripheral iridotomy (LPI) on the magnitude and frequency of headache symptoms in patients with occludable angles. METHODS: Prospective cohort study. Patients with indication for prophylactic LPI due to occludable iridocorneal angle were included. Headache symptoms were assessed before and at least 4 weeks after LPI using the Headache Impact Test-6 (HIT-6) questionnaire. A HIT-6 score of ≥ 50 points was labeled as a clinically significant headache. RESULTS: Thirty-one subjects were included. Prophylactic LPI was performed in 60 eyes, as 2 patients were pseudophakic in the fellow eye. Baseline HIT-6 score was 59.9 ± 11.8, with over three quarters of these patients scoring higher than 50 points (n = 24). A statistically significant reduction in HIT-6 score was found after LPI treatment (45.4 ± 7.7, p < 0.01). Sub-analysis within the clinically symptomatic subjects disclosed a significant improvement after treatment in this group (baseline, 65.3 ± 6.2 vs post-LPI 46.2 ± 8.3, p < 0.01), with a high baseline HIT-6 score being predictive of a symptomatic improvement after LPI (χ2(8) = 15.3, p = 0.001). This is mimicked from the patient's perspective, as the two subjective questions after LPI, concerning pain intensity and frequency, report that 79.2% had a statistically significant improvement of the headaches. CONCLUSIONS: Within our sample, the majority of patients with occludable angles had clinically relevant headaches. LPI provided symptomatic relief in the majority of those patients with high HIT-6 scores. Further studies are needed to explore the relationships between headache and angle anatomy.

Surgical treatment of neovascular glaucoma: a systematic review and meta-analysis.

PURPOSE: This literature review and meta-analysis aims to compare intraocular pressure (IOP) lowering efficacy, failure rates and loss of light perception (LP) rates 6 months after an IOP-lowering surgical procedure in neovascular glaucoma (NVG) eyes. METHODS: MEDLINE and EMBASE were used as data sources. Only studies including NVG patients who underwent two different surgical approaches were considered. The treatment effect measures were (i) weighted mean difference (WMD) for IOP reduction, (ii) risk ratio (RR) for failure rates and (iii) risk difference (RD) for loss of LP. Outcome measures were reported with a 95% confidence interval (CI) and P < 0.05 was considered statistically significant. Analysis was performed using RevMan v5.0. RESULTS: No RCT were retrieved. Seven comparative non-randomised studies were eligible. In glaucoma drainage devices (GDDs) vs cyclophotocoagulation arm, there was no statistical difference in IOP-lowering efficacy (WMD = - 3.63; CI [- 8.69, 1.43], P = 0.16), although failure rates and loss of LP were lower in the GDDs group (RR = 0.64, CI [0.41, 0.99], P = 0.05; and RD = - 0.15, CI [- 0.25, - 0.05], P = 0.004, respectively). In the Ahmed glaucoma valve (AGV) vs trabeculectomy arm, there was no statistical difference in IOP-lowering efficacy and loss of LP (WMD = 0.78, CI [- 2.29, 3.85], P = 0.62 and RD of 0.04, CI [- 0.05, 0.14], P = 0.34, respectively), but failure rates were lower in trabeculectomy group (RR of 2.25, CI [1.14, 3.71], P = 0.02). CONCLUSIONS: There is lack of high-quality evidence on the subject as no RCT were retrieved comparing two different IOP-lowering procedures in NVG patients. Our findings are based, therefore, on non-RCT studies and should be interpreted with caution. There appears to be no difference in IOP-lowering efficacy between GDDs and cyclophotocoagulation, although GDDs appear to be safer. AGV and trabeculectomy also seem to provide similar IOP-lowering results with trabeculectomy showing lower failure rates.

CHOROIDAL THICKNESS IN DIABETIC PATIENTS WITHOUT DIABETIC RETINOPATHY.

PURPOSE: To compare choroidal thickness (CT) between diabetic patients without diabetic retinopathy and a nondiabetic group. To explore how CT relates to disease duration, mean arterial pressure, glycemia, glycosylated hemoglobin, intraocular pressure, and ocular pulse amplitude. METHODS: Choroidal thickness was assessed using a spectral-domain optical coherence tomography and enhanced depth mode at 13 locations (subfoveal and 3 measurements 500 µm apart in 4 directions-nasal, temporal, superior, and inferior). Linear regression models were used. RESULTS: One hundred seventy-five patients were recruited (125 diabetic patients without diabetic retinopathy and 50 nondiabetic patients). In diabetic patients, although without statistical significance, CT showed a trend to be thicker in all locations (6.16-24.27 µm). Choroidal thickness was negatively associated with age (P < 0.001) in both groups, but only in the diabetic group, it was positively associated to ocular pulse amplitude (with a mean increase between 8.5 µm and 11.6 µm for each millimeter of mercury increase in ocular pulse amplitude). Diabetic patients' CT seems to stabilize after 150 months of diabetes, increase with higher glycemia levels (>160 mg/dL) while showing no fluctuation with glycosylated hemoglobin and mean arterial pressure. CONCLUSION: There seems to be a thickening of the choroid in diabetic patients without diabetic retinopathy. Moreover, this tissue may be functionally different in diabetes, as the pattern of associations seems to differ between groups.

Open-Angle Glaucoma: Drug Development Pipeline during the Last 20 Years (1995-2015).

OBJECTIVES: To analyse drug development for open-angle glaucoma during the last 20 years. METHODS: Research was performed by referring to clinical trials registered at the International Clinical Trials Registry Platform (ICTRP). A search for the condition "open-angle glaucoma" with the intervention "drug" was performed. We included trials registered from 01/01/1995 to 01/01/2015, only involving studies in phases 1, 2, and 3. Only studies resorting to novel treatment strategies (either novel drugs or yet-untested fixed associations of approved medication) were considered. RESULTS: We recorded 158 studies for the condition of open-angle glaucoma with a drug-based intervention; 65 of the studies reported phase 2 trials and 74 reported phase 3 trials. Pharmaceutical companies were the primary sponsors of 95.3% of the trials. Most of the studies (66.5%, n = 105) involved a new drug, and the remainder (33.5%, n = 53) tested fixed drug associations. The bulk of the trials (n = 99, 62.7%) involved the use of prostaglandin analogues, either as a comparator or a study drug. In descending order of frequency, the studies conducted involved Rho-kinase inhibitors (n = 15), carbonic anhydrase inhibitors (n = 14), ß-blockers (n = 7), angiostatic steroids (n = 6), α2-adrenergic agonists (n = 4), 5-HT2A receptor agonists (n = 4), and NMDA receptor antagonists (n = 2). A cyclin-dependent kinase inhibitor, an LIM-domain kinase 2 inhibitor, an A1 adenosine receptor agonist, catechin, macrolide, saffron, and seawater were each tested in 1 clinical trial. CONCLUSION: Research into the medical treatment of glaucoma indicates the use of prostaglandin analogues. However, there are a significant number of trials testing other drug classes, particularly Rho-kinase inhibitors. This new focus could lead to a potential increase in the number of therapeutical options for the management of glaucoma in the future.

Intra- and Inter-Rater Agreement of Anterior Lamina Cribrosa Depth Measurements Using Enhanced-Depth Imaging Optical Coherence Tomography.

PURPOSE: To determine intra- and inter-rater agreement of anterior lamina cribrosa depth (ALCD) manual measurements using enhanced-depth imaging optical coherence tomography (EDI-OCT). METHODS: Observational study. EDI-OCT of the optic nerve head was performed in healthy subjects. ALCD was defined as the perpendicular distance between the line connecting both edges of Bruch's membrane opening and the anterior border of the lamina cribrosa (LC), at the maximum depth point. Two experienced operators performed manual ALCD measurements of the LC independently, and one of the observers performed the same measurements twice. Intra- and inter-rater agreement was evaluated using intraclass correlation coefficients (ICC) and concordance correlation coefficients (CCC) for the right eye vertical (REV) and horizontal (REH) scans and left eye vertical (LEV) and horizontal (LEH) scans. RESULTS: 120 eyes of 61 subjects, with a mean age of 62.1 ± 15.0 years. The mean REV, REH, LEV and LEH ALCD were 456.2 ± 84.3, 444.5 ± 92.2, 436.7 ± 81.6, 427.6 ± 82.7 µm, respectively. ALCD intra- and inter-rater ICC and intra- and inter-rater CCC varied between 0.85-0.95, 0.84-0.93, 0.85-0.95 and 0.84-0.93, respectively. CONCLUSIONS: ALCD manual intra- and inter-rater measurements with EDI-OCT showed high agreement. EDI-OCT is a reliable tool for ALCD measurement, which can provide potentially useful information for integrated glaucoma management.

Funduscopic versus HRT III Confocal Scanner Vertical Cup-Disc Ratio Assessment in Normal Tension and Primary Open Angle Glaucoma (The Leuven Eye Study).

PURPOSE: To compare funduscopic and confocal scanning vertical cup-disc ratio (VCDR) assessments and their respective predictive value for estimating functional glaucomatous damage. METHODS: Data from a single eye of open angle glaucoma patients from the Leuven Eye Study were included: age, gender, intra-ocular pressure, visual acuity, refractive error, visual field mean deviation and pattern standard deviation, funduscopic and HRT III VCDRs as well as mean retinal nerve fibre layer thickness. Non-parametric tests to compare differences within and between diagnostic groups were used, and receiver-operating characteristic curves as well as Bland-Altman plots constructed. RESULTS: Three hundred and one eyes of 301 subjects with primary open angle glaucoma (POAG) and normal tension glaucoma (NTG) were included. The average VCDR assessed with HRT III was significantly smaller than the funduscopic measurement (0.69 ± 0.16 vs. 0.81 ± 0.14, respectively; p < 0.001). The predictive value of both measurement techniques did not differ in NTG patients, but the funduscopic estimate yielded a significantly larger predictive power in patients with severe POAG. CONCLUSION: Funduscopic and confocal scanner estimates of VCDR differ significantly and should not be used interchangeably. In POAG patients with severe glaucoma, a subjective VCDR predicts functional glaucomatous damage significantly better.

Diabetic choroidopathy: a review of the current literature.

Diabetic retinopathy is an increasingly prevalent disease, and a leading contributor to the burden of all-cause blindness worldwide. In addition to retinal changes, choroidal abnormalities are common in patients with diabetes. The first studies concerning this vascular structure were based on histologic, indocyanine angiography and laser Doppler flowmetry techniques, but the development of new optical coherence tomography (OCT) technologies and imaging software for enhanced depth imaging (EDI)-OCT in recent years has made it possible to provide more detailed images of the choroidal anatomy and topography.In diabetic patients, several choroidal changes have been described in the literature throughout the years; the recent focus is choroidal thickness, which is significantly different from that in healthy patients. However, understanding choroidal manifestations of diabetic eye disease remains a real challenge, and this gap is hindering efforts towards better defining choroidal evaluation as a predictive factor for disease evolution and treatment response.This review aims to summarize the recent literature concerning changes in choroidal structure in diabetic patients, the relationship to diabetic retinal disease progression, and finally, the current and potential application of the measurement of variations in choroidal thickness for patient management.