COMPARATIVE STUDY OF RNFL THICKNESS USING SPECTRAL DOMAIN OCT AND VISUAL FIELD ANALYSIS USING HUMPHREY FIELD ANALYSER IN CASES OF POAG

Purpose: To compare RNLF structural changes by Spectral Domain- OCT and functional visual eld defects by automated perimetry in Primary Open Angle Glaucoma cases Materials And Methods: A prospective and comparative study was conducted to quantitatively measure the peripapillary retinal nerve ber layer thickness using SD-OCT and compared it with eld changes plotted by Humphrey Field analyser 24-2. The study was conducted at the department of Glaucoma of a tertiary eye care hospital for a period of one year. 60 eyes of 30 patients who diagnosed to have POAG between the age group of 40-65 were included in the study. Patients having substantial media opacity, Retinal pathology and who underwent intra ocular surgeries were excluded from the study. Informed consent obtained from patients who were included in the study. All were examined using Slit lamp, Snellen's chart, Applanation tonometer, Gonioscope, 90 D slit lamp biomicroscope to study Fundus oculi. Fields were plotted using Humphrey eld analyser 24-2 , RNFL thickness measured using SD-OCT. Results: 60 eyes of 30 patients 19 were males 11 were females. 14(23.33%) eyes showed normal visual elds but there was thinning of RNFL was noted in SD-OCT. 41 eyes (68.3%) had visual eld defects which corresponded to thinning of RNFL in that quadrant. 5 eyes (8.3%) showed advanced eld changes and had corresponding thinning of RNFL in that quadrant. Discussion: Results of this study shows a signicant difference in RNFL thickness among all three grades of glaucoma. It was observed that the average RNFL thickness value in moderate glaucoma (66.34 microns) and all quadrant thickness values were similar to Sihota et al study (RNFL-66.07 microns). The mean RNFL thickness +/- Sd (58 +/-5.52) in advanced glaucoma of present study were closely similar with the ndings of Sihota et al study (53.65 +/-14.2). Conclusion: It is concluded that RNFL thickness changes corresponds to Field changes plotted on Humphrey eld analyser in moderate glaucoma. Even in mild cases changes RNFL thickness is noted even though the elds plotted on Humphrey eld analyser doesn't show any changes. So RNFL thickness can be taken as Pre perimetric changes as diagnostic criteria for the diagnosis of POAG.

Optical coherence tomography angiography and Humphrey field analyser for macular capillary non-perfusion evaluation in branch retinal vein occlusion

We non-invasively evaluated macular non-perfused areas (m-NPAs) of branch retinal vein occlusion (BRVO) using optical coherence tomography (OCT) angiography and the Humphrey visual field analyser 10-2 programme (HFA 10-2). We enrolled 30 patients (30 eyes) with macular oedema secondary to BRVO. OCT angiography was used to photograph the macula at 6 × 6-mm; sizes of m-NPAs in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were measured in four areas. For HFA 10-2, we divided the actual measurement threshold of 68 points into four areas and calculated the mean central visual field sensitivity (CVFS). The correlation between the mean m-NPA and mean CVFS (dB) in each area was examined. There was a strong correlation between the m-NPA of each region detected in SCP and DCP, and the mean CVFS of each corresponding area (SCP: r = − 0.83, r = − 0.64, r = − 0.73, and r = − 0.79; DCP: r = − 0.82, r = − 0.71, r = − 0.71, and r = − 0.70), p values were < 0.001 for all. m-NPAs were associated with decreased visual field sensitivity in BRVO. Non-invasive m-NPA evaluation was possible using OCT angiography and HFA 10-2.

Comparing the usefulness of a new algorithm to measure visual field using the variational Bayes linear regression in glaucoma patients, in comparison to the Swedish interactive thresholding algorithm

Background/aimsWe previously reported that the visual field (VF) prediction model using the variational Bayes linear regression (VBLR) is useful for accurately predicting VF progression in glaucoma (Invest Ophthalmol Vis Sci. 2014, 2018). We constructed a VF measurement algorithm using VBLR, and the purpose of this study was to investigate its usefulness.Method122 eyes of 73 patients with open-angle glaucoma were included in the current study. VF measurement was performed using the currently proposed VBLR programme with AP-7700 perimetry (KOWA). VF measurements were also conducted using the Swedish interactive thresholding algorithm (SITA) standard programme with Humphrey field analyser. VF measurements were performed using the 24–2 test grid. Visual sensitivities, test–retest reproducibility and measurement duration were compared between the two algorithms.ResultMean mean deviation (MD) values with SITA standard were −7.9 and −8.7 dB (first and second measurements), whereas those with VBLR-VF were −8.2 and −8.0 dB, respectively. There were no significant differences across these values. The correlation coefficient of MD values between the 2 algorithms was 0.97 or 0.98. Test–retest reproducibility did not differ between the two algorithms. Mean measurement duration with SITA standard was 6 min and 02 s or 6 min and 00 s (first or second measurement), whereas a significantly shorter duration was associated with VBLR-VF (5 min and 23 s or 5 min and 30 s).ConclusionVBLR-VF reduced test duration while maintaining the same accuracy as the SITA-standard.

Comparison of the structure–function relationship between compass microperimetry and Humphrey field analyser in myopic open-angle glaucoma eyes

Background/aimsTo compare the structure–function relationship between compass microperimetry (CMP; CenterVue, Padova, Italy) and Humphrey field analyser (HFA; Carl Zeiss Meditec, Dublin, California, USA) in open-angle glaucoma (OAG) eyes with myopia.MethodsCircumpapillary retinal nerve fibre layer thickness (cpRNFLT) and visual field (VF) mean sensitivity (MS) were obtained in 90 OAG subjects using the optical coherence tomography, CMP and HFA in a random order. The global and sectoral structure–function relationships between the cpRNFLT and VFMS were assessed with different VF devices (CMP vs HHA) in OAG eyes with and without myopia.ResultsOverall, the global and regional structure–function relationships between the two devices did not show significant differences except for the superotemporal sector. In the myopic subgroup, the global association between the average cpRNFLT and VFMSCMP was significantly stronger than that between the average cpRNFLT and VFMSHFA (r=0.806 vs. 0.720, p=0.035). The presence of myopia and higher global cpRNFLT were significantly associated with the greater global VFMS differences between the two devices (p<0.05).ConclusionIn general, structure–function relationship is similar between CMP and HFA in OAG eyes. However, the global structure–function relationship is significantly stronger with CMP than with HFA in OAG eyes with myopia.

Auditing service delivery in glaucoma clinics using visual field records: a feasibility study

ObjectiveThis study aimed to demonstrate that large-scale visual field (VF) data can be extracted from electronic medical records (EMRs) and to assess the feasibility of calculating metrics from these data that could be used to audit aspects of service delivery of glaucoma care.Method and analysisHumphrey visual field analyser (HFA) data were extracted from Medisoft EMRs from five regionally different clinics in England in November 2015, resulting in 602 439 records from 73 994 people. Target patients were defined as people in glaucoma clinics with measurable and sustained VF loss in at least one eye (HFA mean deviation (MD) outside normal limits ≥2 VFs). Metrics for VF reliability, stage of VF loss at presentation, speed of MD loss, predicted loss of sight years (bilateral VF impairment) and frequency of VFs were calculated.ResultsOne-third of people (34.8%) in the EMRs had measurable and repeatable VF loss and were subject to analyses (n=25 760 patients). Median (IQR) age and presenting MD in these patients were 71 (61, 78) years and −6 (–10, –4) dB, respectively. In 19 264 patients with >4 years follow-up, median (IQR) MD loss was −0.2 (−0.8, 0.3) dB/year and median (IQR) intervals between VF examinations was 11 (8, 16) months. Metrics predicting loss of sight years and reliability of examinations varied between centres (p<0.001).ConclusionThis study illustrates the feasibility of assessing aspects of health service delivery in glaucoma clinics through analysis of VF databases. Proposed metrics could be useful for blindness prevention from glaucoma in secondary care centres.

Utility of CLOCK CHART binocular edition for self-checking the binocular visual field in patients with glaucoma

Background/aimsCar accidents caused by drivers unaware of their visual field (VF) defects under binocular vision have become an issue. We developed a simple self-check chart (CLOCK CHART binocular edition (CCBE)) to help patients with glaucoma recognise their abnormalities in the binocular VF and evaluated its usefulness.MethodsThe chart has four targets displayed at 10°, 15°, 20° and 25° eccentricities. The examinee gradually rotates the chart 360° clockwise. At every 30°, the examinee confirms the fixation and indicates if all four targets can be seen. This study enrolled 88 eyes of 44 patients with glaucoma (mean age, 64.4±13.1 years) and 64 eyes of 32 visually normal individuals (mean age, 32.0±8.4 years). Except the CCBE test, static VF testing using the Humphrey field analyser (HFA) Swedish Interactive Threshold Algorithm-Standard 30-2 and binocular Esterman programmes was also performed for the subjects with glaucoma.ResultsVF abnormality was defined as two or more contiguous points with a sensitivity of <10 dB within the central 30°. The CCBE test had sensitivities of 85% and 82% with respect to the HFA and Esterman results, respectively. We also used the British VF standards for Group 1 (car/motorcycle) drivers, and a sensitivity of 88% was obtained for the CCBE. The chart had a specificity of 100% for the visually normal subjects.ConclusionThe CCBE test enables drivers with glaucoma to notice their VF abnormalities under binocular condition. The application of this simple self-check method appears promising for occasions such as driver licensing.