Repeatability of Goldmann tonometry performed by optometry students on glaucoma patients.

BACKGROUND: The purpose of this study was to evaluate the repeatability of masked Goldmann tonometry performed by optometry students on patients with glaucoma. METHODS: Subjects were recruited from among patients scheduled to undergo selective laser trabeculoplasty at the Rosenberg School of Optometry clinic. Each subject had masked Goldmann tonometry performed by three examiners at each office visit: two fourth professional-year optometry interns and an attending optometrist. Each examiner performed three sequential masked tonometry measurements on each eye. RESULTS: Twenty-eight interns and two optometrists performed masked Goldmann tonometry on 12 glaucoma patients. The co-efficient of variation was 9.1 per cent for the right eye and 12.1 per cent for the left eye for interns compared with 6.4 per cent right eye and 6.6 per cent left eye for optometrists. There was significant interaction between intern and patient on co-efficient of variation (two-factor analysis of variance, p = 0.005), indicating co-efficient of variation was influenced by both intern and patient factors. No such interaction was found for optometrist-performed measurements (p = 0.96). Mean interobserver difference for interns ranged between 0.9 and 3.1 mmHg, with 95 per cent limits of agreement that were proportional to mean intraocular pressure. Mean interobserver difference for optometrists ranged between 0.6 and 1.8 mmHg without proportionality bias. At higher pressure levels intern measurements became more variable and tended to overestimate optometrist measurements. CONCLUSIONS: Both intraobserver and interobserver repeatability of masked tonometry was lower for interns than experienced optometrists. Intern performance differed from optometrists in that intern measurements became more variable at higher intraocular pressure levels and were significantly influenced by patient factors. The present results support the need for trainee exposure to patients with abnormally elevated intraocular pressure. Research into factors that influence trainee Goldmann tonometry repeatability is needed.

Visual evoked potential repeatability using the Diopsys NOVA LX fixed protocol in normal older adults.

PURPOSE: The purpose of this study was to evaluate the intrasession and intersession repeatability of visual evoked potentials in normal adults over 40 years of age as recorded using the Diopsys NOVA LX fixed protocol. METHODS: Inclusion criteria were adults aged over 40 years with best corrected distance acuity of 20/40 or better in each eye. Subjects underwent three consecutive visual evoked potential examinations using the Diopsys NOVA LX fixed protocol. All examination procedures were carried out in accordance with the manufacturer recommendations. To assess intersession repeatability, nine subjects returned in 2-6 weeks for repeat examination. RESULTS: A total of 46 subjects were recruited. Mean ± SD age: 53±9 years (range: 40-84 years); 69% of subjects were female and 80% were non-white. Coefficients of variation (CVs) and intra-class correlation coefficients (ICCs) revealed greater repeatability for P100 latency (CV: 3%-7%; ICC: 0.39-0.76) than for P100 amplitude (CV: 21%-33%; ICC: 0.34-0.69) and greater repeatability for recordings made with high contrast stimuli (amplitude CV: 21%-23%; latency CV: 3%-7%) than low contrast stimuli (amplitude CV: 24%-33%; latency CV: 6%-7%). Minimum detectable change values ranged between 4.50 and 9.95 µv for amplitude and 8.16-15.26 ms for latency. Repeatability was not influenced by age, sex, or race. CONCLUSION: The Diopsys NOVA LX fixed protocol demonstrated clinically acceptable intrasession and intersession repeatability in these healthy older adults, with latency being more repeatable than amplitude and examinations employing high contrast stimuli being more repeatable than those using low contrast stimuli.

Association of Diopsys® Short-duration Transient Visual Evoked Potential Latency with Visual Field Progression in Chronic Glaucoma.

AIM: To determine the association of Diopsys® NOVA-LX amplitude and latency abnormality scores with perimetric staging of chronic glaucoma, and to explore potential single-visit short-duration transient visual evoked potential (SD-tVEP) trend detection ability utilizing Humphrey 30-2 field progression data. MATERIALS AND METHODS: Setting: Glaucoma subspecialty clinic. Participants: Treated adult chronic glaucoma patients undergoing SD-tVEP evaluation. Main outcome measures: (1) Proportion of eyes designated as suspect or abnormal by the NOVA-LX multifactorial algorithm were determined as a function of glaucoma severity using the most recent Humphrey visual field analyzer (HVFA) 30-2 field. (2) Association between long-term HVFA-guided progression analysis (GPA) annual slopes and SD-tVEP abnormality was assessed to determine whether a single VEP test might help to identify eyes more prone to progressive visual field (VF) loss. RESULTS: One hundred and thirty-three eyes of 84 patients (mean age 68 years) were analyzed. The SD-tVEP abnormality increased proportionately with severity of VF loss under high-contrast (Hc) test conditions for both latency (p = 0.001) and amplitude (p < 0.01). The HVFA progression analysis printouts existed for 91 eyes (mean 12.3 fields per eye/range 5-18). Nearly three-quarters (72.5%) of eyes with mean annual HVFA progression >0.7 dB/year (n = 29) had single-visit VEP latency abnormalities. Fewer than half (46.7%) of the remainder (n = 62) showed latency abnormality. Mean progression for eyes with abnormal vs normal VEP latency was -0.87 ± 0.3 dB/year vs -0.32 ± 0.4 dB/year. CONCLUSION: Diopsys NOVA-LX Hc latency abnormality shows strong association with VF loss among a diverse population of clinical patients undergoing active treatment for chronic glaucoma, and appears likely to afford clinically useful trend-detecting test. CLINICAL SIGNIFICANCE: The SD-tVEP has the potential to serve as a single-visit clinical indicator to identify glaucoma patients at high risk for VF progression.How to cite this article: Trevino R, Sponsel WE, Majcher CE, Allen J, Rabin J. Association of Diopsys® Short-duration Transient Visual Evoked Potential Latency with Visual Field Progression in Chronic Glaucoma. J Curr Glaucoma Pract 2018;12(1):29-35.