Glaucoma diagnostics

Multiple Sclerosis: What Methods are Available for the Assessment of Subclinical Visual System Damage?

We aimed to assess the visual fields and optical coherence tomography (OCT) measurements in patients with multiple sclerosis (MS) to detect subclinical visual system disease. The study included 15 MS patients with previous optic neuritis (Group I), 17 MS patients without previous optic neuritis (Group II), and 14 healthy controls (Group III). Each subject underwent standard automated perimetry (SAP), frequency doubling technology perimetry (FDTP), and OCT. The mean deviation of SAP in Group I was lower than those in Groups II (p = .018) and III (p = .001). The pattern standard deviation of SAP in Group I was higher than those in Group III (p < .0001). The mean deviation of FDTP in Groups I and II was lower than those in Group III (p = .0001 and p = .016, respectively). The temporal quadrant of the retinal nerve fibre layer in Group I was thinner than those in Groups II and III (p = .005 and p = .003, respectively). The mean macular volume in Group I was thinner than those in Groups II and III (p = .004 and p = .002, respectively). A single method is inadequate for establishing early and/or mild visual impairment in MS. All conventional and non-conventional techniques are complementary in demonstrating subclinical visual damage in MS.

Impact and Challenges of Integrating Artificial Intelligence and Telemedicine into Clinical Ophthalmology

ABSTRACT

Aging populations and worsening burden of chronic, treatable disease is increasingly creating a global shortfall in ophthalmic care provision. Remote and automated systems carry the promise to expand the scale and potential of health care interventions, and reduce strain on health care services through safe, personalized, efficient, and cost-effective services. However, significant challenges remain. Forward planning in service design is paramount to safeguard patient safety, trust in digital services, data privacy, medico-legal implications, and digital exclusion. We explore the impact and challenges facing patients and clinicians in integrating AI and telemedicine into ophthalmic care-and how these may influence its direction.

Amsler grid test for detection of advanced glaucoma in Ethiopia

Objective

This study was done to determine the validity of amsler grid test black on white (BOW), as well as white on black (WOB) for identifying central visual field (VF) defects in patients with advanced glaucoma.

Design

Prospective study.

Participants

We prospectively included 100 consecutive eyes of 88 adult patients with advanced glaucoma and 100 eyes of 100 normal individuals. We used a lottery method to choose the side of the eye for the control groups.

Methods

All participants had reliable Humphrey 10–2 Swedish Interactive Threshold Algorithm (SITA) standard VF. Both the BOW and WOB amsler grid tests were done for each group. Sensitivity, specificity, and positive and negative predictive values of the amsler grid scotoma area were calculated with the 10–2 VF as the reference standard.

Results

The mean ± standard deviation (SD) of age and the 10–2 VF mean deviation (MD) of advanced glaucoma eyes were 59.8 ± 11.8 (range 34–84) years and -19.94 ± 9.8(range -34.98–-0.52) respectively. Among 108 eyes with normal 10–2 VF test, 103 had a normal BOW amsler grid test and 5 had an abnormal BOW test. Among 92 eyes with an abnormal 10–2 VF test, 74 had an abnormal and 18 had normal BOW amsler grid test. Sensitivity, specificity, and positive and negative predictive values of the BOW amsler grid test were 80.4%, 95.4%, 93% and 85.1% respectively whereas that of the WOB amsler grid test were 71.7%, 95.4%, 93% and 72.8% respectively.

Conclusion

The sensitivity and specificity of both BOW and WOB amsler grid tests were high in detecting VF defects in advanced glaucoma.

Validity, Usefulness and Cost of RETeval System for Diabetic Retinopathy Screening

Purpose

We studied the validity, usefulness, and relative cost to detect diabetic retinopathy (DR) and sight-threatening DR (STDR) by using a hand-held electrophysiologic tool compared to digital fundus photography.

Method

Patients with diabetes attending the screening unit of King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia were evaluated by “RETeval”, Amsler grid, and digital dilated fundus photography. Fundus images were evaluated by a retina specialist to determine grade of DR. The sensitivity and specificity of STDR and DR screening compared to photography were calculated, as well as “RETeval” combined with Amsler grid testing. The area under the curve (AUC) of “RETeval” screening outcome was calculated.

Result

We analyzed data of 400 diabetic patients. The prevalence of DR of any grade was 48.8% (95% confidence interval [CI], 43.9–53.7) while the prevalence of STDR was 27% (95% CI, 22.6–31.4). The outcome of RETeval test was “fail” (based on 20 μV or more amplitude of electrophysiologic spikes) in 351 (87.8%; 95% CI, 84.5–91.0) eyes. The sensitivity of the device was 95.4% and the specificity was 17.5%. Thus, the sensitivity of sequential testing with RETeval and Amsler grid test was 30.1% and the specificity was 80.1%. The AUCs for STDR and DR in general were 76.6% and 50.6%, respectively.

Conclusions

“RETeval” is a rapid screening device with excellent sensitivity for detecting STDR. It has potential as a first level screening tool to detect patients who require further evaluation.

Translational Relevance

Retinal function, such as electrophysiology, can be used as a new concept for screening for DR.

Predictive value of screening tests for visually significant eye disease

PURPOSE

To determine the predictive value of ophthalmic screening tests with visually significant eye disease in a cohort of American Indian/Alaskan Natives from the Pacific Northwest.

DESIGN

Validity assessment of a possible screening protocol.

METHODS

Ophthalmic technicians performed a screening examination including medical and ocular history, best-corrected visual acuity, limbal anterior chamber depth assessment, frequency-doubling technology perimetry (FDT, C-20-5), confocal scanning laser ophthalmoscopy, nonmydriatic digital photography, and tonometry on 429 participants. An ophthalmologist performed a comprehensive eye examination on subjects with 1 or more abnormal screening tests and a random selection of those with normal screening tests. We used univariate and multivariate logistic regression to determine the association between abnormal screening test results and visually significant eye disease. We also determined the predictive value of screening tests with ocular disease.

RESULTS

Univariate analysis identified history of eye disease or diabetes mellitus (P < .001), visual acuity <20/40 (P < .001), abnormal/poor-quality confocal scanning laser ophthalmoscopy (P < .001), abnormal FDT (P < .001), and abnormal/poor-quality nonmydriatic imaging (P < .001) as associated with visually significant eye disease. A multivariate analysis found visually significant eye disease to be associated (P < .001; receiver operating characteristic curve area = 0.827, negative predictive value = 84%) with 4 screening tests: visual acuity <20/40, abnormal/poor-quality nonmydriatic imaging, abnormal FDT, and abnormal/poor-quality confocal scanning laser ophthalmoscopy.

CONCLUSIONS

Ophthalmic technicians performing a subset of screening tests may provide an accurate and efficient means of screening for eye disease in an American Indian/Alaskan Native population. Confirmation of these results in other populations, particularly those with a different profile of disease prevalence, is needed.

Flicker defined form, standard perimetry and Heidelberg retinal tomography: Structure-function relationships

OBJECTIVE

To compare flicker defined form (FDF) perimetry using the Heidelberg edge perimeter (HEP) with standard automated perimetry (SAP) on the Humphrey visual field (HVF) analyzer and to compare their relationship to structural measurements acquired with the Heidelberg retina tomograph.

DESIGN

Prospective, observational study.

PARTICIPANTS

Thirty-one glaucomatous eyes with varying severity and 13 normal control eyes were included in this analysis.

METHODS

All subjects underwent FDF testing on the HEP using the 24-2 protocol by the adaptive staircase thresholding algorithm standard strategy and SAP on the HVF analyzer 750 II using the SITA-Standard 24-2 test. Heidelberg retina tomography (HRT) testing was obtained for each patient. Spearman correlation coefficient, mean deviation (MD), and pattern standard deviation measurements by both machines were compared.

RESULTS

FDF and SAP MD were significantly correlated (r = 0.81, p < 0.001). FDF and SAP MD were significantly correlated with HRT cup/disc ratio (FDF MD: p < 0.001; SAP MD: p = 0.003), disc area (FDF MD: p = 0.005; SAP MD: p = 0.059), rim volume (FDF MD: p < 0.001; SAP MD: p < 0.001), and retinal nerve fibre layer (FDF MD: p < 0.001; SAP MD: p < 0.001).

CONCLUSIONS

This pilot study shows that the MD parameter of FDF correlated with SAP results. FDF and SAP had significant correlations with HRT parameters in glaucomatous and healthy eyes. The potential utility of FDF in the clinical management of glaucoma requires further investigation.

Diagnostic Consistency and Relation Between Optical Coherence Tomography and Standard Automated Perimetry in Primary Open-Angle Glaucoma

PURPOSE

To assess diagnostic consistency and relation between spectral-domain optical coherence tomography (SD-OCT) and standard automated perimetry (SAP) in patients with primary open-angle glaucoma (POAG).

METHODS

This retrospective study comprised 51 eyes of 51 patients with a confirmed diagnosis of POAG. The qualitative and quantitative SD-OCT parameters (retinal nerve fiber layer thicknesses [RNFL; average, superior, inferior, nasal and temporal], RNFL symmetry, rim area, disc area, average and vertical cup/disc [C/D] ratio and cup volume) were compared with parameters of SAP (mean deviation, pattern standard deviation, visual field index, and glaucoma hemifield test reports).

RESULTS

Fifty-one eyes of 51 patients with POAG were recruited. Twenty-nine eyes (56.9%) had consistent RNFL and visual field (VF) damage. However, nine patients (17.6%) showed isolated RNFL damage on SD-OCT and 13 patients (25.5%) had abnormal VF test with normal RNFL. In patients with VF defect, age, average C/D ratio, vertical C/D ratio, and cup volume were significantly higher and rim area was lower when compared to those of the patients with normal VF. In addition to these parameters, worsening in average, superior, inferior, and temporal RNFL thicknesses and RNFL symmetry was significantly associated with consistent SD-OCT and SAP outcomes.

CONCLUSIONS

In routine practice, patients with POAG can be manifested with inconsistent reports between SD-OCT and SAP. An older age, higher C/D ratio, larger cup volume, and lower rim area on SD-OCT appears to be associated with detectable VF damage. Moreover, additional worsening in RNFL parameters might reinforce diagnostic consistency between SD-OCT and SAP.

Tug of war

A 74-year-old man had reproducible superior and inferior arcuate visual field defects in the left eye only that were initially believed to be caused by primary open-angle glaucoma. Diagnostic evaluation with the aid of optical coherence tomography revealed extrafoveal vitreomacular traction (VMT) with secondary retinal thickening and schisis. We discuss the evaluation of non-glaucomatous visual field defects and review the literature on the pathogenesis, clinical manifestations, and treatment of VMT syndrome.