Comparison of Visual Field Test Measurements With a Novel Approach on a Wearable Headset to Standard Automated Perimetry.

PRCIS: This study of inter-test comparability of a novel visual field application installed on an augmented-reality portable headset and Humphrey field analyzer Swedish interactive thresholding algorithm (SITA) Standard visual field test demonstrates the excellent correlation of mean deviation (MD) and mean sensitivity (MS). PURPOSE: To determine the correlation between visual field testing with novel software on a wearable headset versus standard automated perimetry. PATIENTS AND METHODS: Patients with and without visual field defects attributable to glaucoma had visual field testing in one eye of each patient with 2 methods: re:Imagine Strategy (Heru, Inc.) and the Humphrey field analyzer (Carl Zeiss Meditec, Inc.) SITA Standard 24-2 program. Main outcome measures included MS and MD, which were evaluated by linear regression, intraclass correlation coefficient (ICC), and Bland Altman analysis for assessment of the mean difference and limits of agreement. RESULTS: Measurements from 89 eyes of 89 patients (18 normal and 71 glaucomas) were compared with both instruments. Linear regression analysis demonstrated an excellent Pearson correlation coefficient of r = 0.94 for MS and r = 0.95 for MD. ICC analysis demonstrated high levels of concordance (ICC = 0.95, P < 0.001 for MS and ICC = 0.94, P < 0.001 for MD). Bland-Altman analysis determined a small mean difference between the two devices (Heru minus Humphrey) of 1.15 dB for MS and 1.06 dB for MD. CONCLUSIONS: The Heru visual field test correlated well with SITA Standard in a population of normal eyes and eyes with glaucoma.

Non-invasive Assessment of Central Retinal Artery Pressure: Age and Posture-dependent Changes.

Purpose: Assessment of Ocular Perfusion Pressure (OPP) requires estimation of the Mean Central Retinal Artery Pressure (MCRAP) [OPP = MCRAP-IOP]. In a seated position, MCRAP is currently estimated as 2/3 of the Mean Arterial Pressure (MAP) to account for the hydrostatic reduction of MAP at eye level. We tested a surrogate method for direct MCRAP assessment by measuring MAP with Arm-Up and cuff at eye level (AUMAP) at different postures and ages. Methods: MAP and AUMAP were assessed in a mixed population of 136 subjects (mean age 44 ± 17.39 years) including healthy participants (N = 30) and patients with optic neuropathies (Glaucoma suspects, N = 14; Open-Angle Glaucoma, N = 26, LHON, N = 19; MS, N = 47) not expected to alter systemic blood pressure. None of the subjects had history of carotid stenosis or pharmacological treatment to regulate blood pressure. AUMAP was also tested in two subgroups in supine (N = 42) and -10° Head Down body Tilt position (HDT, N = 46). Results: In the seated position, both 2/3MAP and AUMAP increased with increasing age, however with steeper (2x) slope for AUMAP (P < .0001). With decreasing angle of body tilt, AUMAP increased while MAP decreased. The mean AUMAP/MAP ratio (posture coefficient) was, seated, 0.73 (SE 0.003); supine, 0.90 (SE 0.005); HDT, 0.97 (SE 0.005). In the seated position only, the AUMAP/MAP ratio significantly increased with age (P < .0001). Mean posture coefficients obtained with AUMAP were in the range of those based on either direct ophthalmodynamometric measurements or hydrostatic estimations. Conclusions: Surrogate measurement of MCRAP in individual subjects is feasible using the simple AUMAP approach that provides a straightforward estimation of OPP (OPP = AUMAP - IOP) at different body postures. The standard method OPP = 2/3*MAP-IOP in the seated posture underestimates OPP at older ages. Clinical estimation of OPP would benefit from the use of AUMAP, in particular for head-down postures.

Head-down Posture in Glaucoma Suspects Induces Changes in IOP, Systemic Pressure, and PERG That Predict Future Loss of Optic Nerve Tissue.

PURPOSE: To obtain pilot data on posture-induced changes of intraocular pressure (IOP), systemic pressure, and pattern electroretinogram (PERG) predictive of future optic nerve tissue loss glaucoma suspects (GSs). METHODS: Mean peripapillary retinal fiber layer thickness (RNFLT) was measured with optical coherence tomography 2 times/year in 28 GS aged 58±8.9 years over 5.0±0.73 years. All patients had a baseline PERG, IOP, and brachial blood pressure measurements in the seated and -10 degrees head-down-body-tilt (HDT) position. Outcome measures were seated/HDT PERG amplitude and phase, IOP, mean arterial blood pressure, and estimated ocular perfusion pressure. An additional group of 11 similarly aged controls aged 56.9±13 years was tested for comparison. RESULTS: Although all GS had initial RNFLT in the normal range, 9/28 of them developed significant (P<0.05) loss of mean RNFLT [thinners (T)] over the follow-up period as opposed to 19/28 who did not [nonthinners (NT)]. Significant (P<0.05) differences between similarly aged controls, NT, and T were found in PERG amplitude, PERG phase, mean arterial blood pressure, IOP, and ocular perfusion pressure. A nominal logistic regression using baseline PERG and hemodynamic variables was able to distinguish T from NT with an area under receiving operator characteristic of 0.89 (SE, 0.07). CONCLUSIONS: Baseline PERG, IOP, and systemic blood pressure, together with their changes upon HDT, may have predictive value for future loss of optic nerve tissue in GS. This study supports the rationale for a full-scale clinical trial to identify patients at high risk of development of glaucoma.

Comparison of Matrix with Humphrey Field Analyzer II with SITA.

PURPOSE: To study the performance of the Matrix perimeter compared with the Humphrey Field Analyzer II (HFA) with the Swedish Interactive Thresholding Algorithm over the range of contrast sensitivities each machine could estimate. METHODS: Fifty stable glaucoma subjects at various stages of disease and three normal subjects had visual fields testing done on five different days within 8 weeks with both perimeters. Intraclass correlation coefficient of mean deviation, pattern standard deviation, and the SD of repeat measurements were evaluated. The repeatability of the sensitivity estimates at individual locations and global indices was quantified, as well as their dependence on disease severity. The relationship between sensitivity determinations with the two instruments was explored (principal curve analysis). RESULTS: Mean deviation on the HFA ranged from -31 to +2.5 dB. The mean deviation and pattern standard deviation had intraclass correlation coefficients above 0.90 for both instruments. Over most of the useful range (above 20 dB on the HFA), a difference of 1 dB for the Matrix corresponded to a difference of 2 dB for the HFA. The SD of repeat measurements increased with disease severity with HFA, but not with Matrix, except that values of 12 or 34 dB were highly variable on repeat. Variability was reduced for both HFA and Matrix when duplicate sensitivity values were used. A single Matrix test provided only 15 possible sensitivity values, unevenly spaced, but the average of duplicate measurements provided more numerous sensitivity values. A learning effect was detected for Matrix. CONCLUSIONS: The decibel values reported by the two machines are not equivalent. Variability of sensitivity determinations is affected more by the sensitivity level with HFA than with Matrix. Duplicate measurements for baseline and follow-up evaluation could be important, especially for Matrix. Further information on learning effects is needed, as is commercially available progression software for Matrix.

Clinical findings and management of conjunctival intraepithelial neoplasia.

BACKGROUND: Conjunctival intraepithelial neoplasia (CIN) is the most common tumor of the ocular surface and is a precursor to invasive squamous cell carcinoma. CIN comprises a spectrum of premalignant epithelial neoplasia that usually begins near the limbus and spreads to the cornea. METHODS: This case report reviews the clinical findings and management of CIN, with a discussion of the histopathology and etiology of this tumor. CONCLUSION: CIN has a variety of clinical presentations, including gelatinous, leukoplakic, or papilliform. Because of their malignant potential, these lesions must be differentiated carefully and treated promptly. Traditional management of CIN is surgical excision with cryotherapy, but other topical treatments are being explored with promising results.

Effect of cataract and its removal on signal strength and peripapillary retinal nerve fiber layer optical coherence tomography measurements.

PURPOSE: To assess the effect of cataract on optical coherence tomography (OCT), signal strength (SS), and peripapillary retinal nerve fiber layer (RNFL) thickness measurements. METHODS: Peripapillary RNFL thickness measurements were obtained by Stratus OCT scans using the Fast RNFL thickness (3.4) acquisition protocol before and after cataract extraction in 45 patients with cataract, including 23 glaucoma patients. Cataracts were graded according to the Lens Opacities Classification System III. RESULTS: The postoperative RNFL thickness and SS were 9.3% (P=0.001) and 24.1% (P<0.001) higher than before surgery, respectively. There was greater postoperative change in RNFL thickness measurements in patients with lower preoperative RNFL measurements (r=-0.63, P<0.001) and SS (r=-0.59, P<0.001). Eyes with preoperative SS more than 6 had no significant difference between precataract and postcataract surgery RNFL thickness (P=0.14). There was no significant difference in RNFL thickness change between eyes with cataract only (10.9±20.8 µm) and those with cataract and glaucoma (7.0±14.7 µm; P=0.81). CONCLUSIONS: Cataracts may decrease peripapillary RNFL thickness measurements and the SS on OCT scans. Thinning of the peripapillary RNFL suggestive of glaucomatous progression may be the result of artifact from advancing cataract rather than actual structural changes in the peripapillary RNFL. Peripapillary RNFL thickness measurements should be interpreted with caution in glaucomatous eyes with significant cataract, particularly if the SS is attenuated.

Characteristics of optic nerve head drusen on optical coherence tomography images.

BACKGROUND AND OBJECTIVE: To describe the characteristics of optic nerve head drusen in optical coherence tomography (OCT) images. PATIENTS AND METHODS: Cross-sectional images of the optic nerve were obtained in seven patients with optic nerve head drusen with Stratus and spectral-domain OCT (Carl Zeiss Meditec, Dublin, CA). These were compared to optic disc photographs, autofluorescence, and echography images. For comparison, these tests were performed on four patients with papilledema and three patients with small optic discs. RESULTS: Optic nerve head drusen typically elevated the disc surface and appeared as an optically empty cavity, sometimes with a perceptible reflection from the posterior surface. The disc surface was also elevated in cases of papilledema, but had a strong anterior reflectance behind which there was no visible structure. The surface of the small optic nerves was slightly elevated, but with less anterior reflectance. CONCLUSION: Optic nerves with drusen showed features in these OCT images that were distinct from cases of papilledema or small optic discs.

Evaluation of decision rules for frequency-doubling technology screening tests.

PURPOSE: Frequency-doubling technology (FDT) perimetry has shown promise as a screening test for glaucoma. This study investigates different possible decision rules for FDT screening by applying them to groups of normal and glaucoma subjects. METHODS: Within three centers, 218 subjects (aged 15-88 years; 78 with glaucoma, 140 without ocular disease) were each tested twice with the screening program of the FDT perimeter. The subjects consisted of 140 normal subjects with no evidence of glaucoma or other ocular disease likely to affect the visual field and 78 subjects with a diagnosis of glaucoma and no other ocular disease. Fifteen decision rules were applied to the data to compare their sensitivity and specificity. RESULTS: Estimated specificities of the different decision rules ranged from 78% to 99%, although with this sample size, the confidence intervals for these estimates are quite large. Estimated sensitivities ranged from 40% to 72%. Suggested criteria for distinguishing normal subjects from those with glaucoma seem to be either a cluster of two or more adjacent locations abnormal at the p < 2% level with at least one location confirmed or a single location very abnormal (p < 1%) and confirmed. CONCLUSIONS: Specificity was clearly improved by confirming an apparently abnormal test result by repeating the screening test outweighing the resultant small loss in sensitivity. These findings provide useful information for making an informed choice of decision rules for FDT screening results.

Sensitivity and specificity of the StratusOCT for perimetric glaucoma.

PURPOSE: To determine the sensitivity and specificity of measurements of the retinal nerve fiber layer (RNFL) using the StratusOCT in glaucoma subjects with visual field (VF) defects. DESIGN: Prospective cross-sectional study. PARTICIPANTS: One hundred nine normal and 63 glaucoma subjects. TESTING: Fast RNFL scans were performed in one eye of each patient using the StratusOCT. MAIN OUTCOME MEASURES: Sensitivity and specificity of different optical coherence tomography (OCT) criteria for identifying glaucoma subjects with glaucomatous VF defects. SECONDARY OUTCOME MEASURES: Areas under the receiver operating characteristic curves (AROCs) for various OCT parameters. RESULTS: Severity of VF defects in the glaucoma group was distributed between mild (18 subjects), moderate (21 subjects), and severe (24 subjects). The average mean deviation of the glaucoma fields was -8.4 decibels (dB), with a standard deviation of 6.0 dB and a range from -0.14 to -28.0 dB. The sensitivity and specificity using a criterion of average RNFL thickness abnormal at the <5% level were 84% and 98%, respectively. The sensitivity and specificity using a criterion of average RNFL thickness abnormal at the <1% level were 68% and 100%. The sensitivity and specificity of using a criterion of >or=1 quadrants abnormal at the <5% level were 89% and 95%. The sensitivity and specificity of using a criterion of >or=1 quadrants abnormal at the <1% level were 83% and 100%. The sensitivity and specificity of using a criterion of >or=1 clock hours abnormal at the <5% level were 89% and 92%. The sensitivity and specificity of using a criterion of >or=1 quadrants abnormal at the <1% level were 83% and 100%. The AROC for mean RNFL thickness was 0.966. Other high AROC values included the superior quadrant (0.952), inferior quadrant (0.971), inferotemporal clock hour at 7-o'clock (right eye) and 5-o'clock (left eye) (0.959), 6-o'clock hour (0.940), superotemporal clock hour at 11-o'clock (right eye) and 1-o'clock (left eye) (0.935), and 12-o'clock hour (0.924). CONCLUSIONS: The sensitivity and specificity of RNFL measurements using the new StratusOCT for glaucoma with manifest VF defects are excellent. The best parameters seem to be >or=1 quadrants abnormal at the or=1 clock hours abnormal at the

A cost analysis of the prostaglandin analogs.

BACKGROUND: The efficacy, ease of use, and favorable side effect profile has increased the popularity of the prostaglandin analogs for topical treatment of a variety of glaucoma types. We undertook a cost analysis study of all the prostaglandin analogs. METHODS: Mean number of drops per bottle, mean drop volume, total bottle volume, percent overfill per bottle, mean national bottle cost, daily cost of therapy, and yearly cost of therapy were calculated for all four of the prostaglandin analogs. RESULTS: Yearly cost of monocular therapy was $230.68 for latanoprost, $219.37 for travoprost, $211.34 for bimatoprost, and $178.85 for unoprostone. Unoprostone was by far the least expensive of the prostaglandin analogs tested. Bimatoprost, latanoprost, and travoprost were essentially the same price, varying in yearly cost to the patient by less than twenty dollars. Bimatoprost had the most expensive bottle price, unoprostone the least expensive. Bimatoprost also had the largest percentage of overfill from labeled volume. Unoprostone had the most monocular treatment days per bottle. CONCLUSION: Cost, in addition to efficacy and side affect profile, should be considered when determining which prostaglandin analog to prescribe to glaucoma patients.

Comparison of glaucomatous visual field defects using standard full threshold and Swedish interactive threshold algorithms.

OBJECTIVES: To compare the severity, size, and depth of glaucomatous visual field defects using standard full threshold (FT), Swedish interactive threshold algorithm (SITA) standard (SS), and SITA fast (SF) algorithms of the Humphrey perimeter. METHODS: A prospective observational case series of 77 patients with glaucoma performed FT, SS, and SF 30-2 white-on-white testing programs on the same day on 2 occasions for 1 month. The severity of defects was compared using the mean deviation, pattern standard deviation, Advanced Glaucoma Intervention Study, and Hodapp-Anderson-Parrish severity scores. The sizes of defects were compared using the total number of abnormal points on the pattern deviation plot that fit standard criteria for glaucomatous visual field defects. The depths of the defects were compared using the sum of the threshold values for points identified in the pattern deviation plot as fitting criteria for glaucomatous defects. RESULTS: The mean deviations were slightly better using the SS (-9.6 +/- 7.1 dB) or the SF (-9.1 +/- 6.7 dB) algorithm compared with the FT algorithm (-10.3 +/- 7.1 dB) (P<.005). There were no significant differences in pattern standard deviations between SS (8.6 +/- 4.0, P =.08) and SF (8.1 +/- 3.6, P =.19) compared with FT (8.3 +/- 3.3), although the pattern standard deviation was higher in SS fields compared with SF fields (P<.001). Advanced Glaucoma Intervention Study scores were slightly better when the SS (7.5 +/- 5.6) or SF (7.2 +/- 5.4) algorithm was used compared with the FT algorithm (8.6 +/- 5.4) (P<.001). The sizes of glaucomatous defects were slightly larger using the SS (20.9 +/- 10.7) algorithm compared with the FT algorithm (19.2 +/- 10.9) (P =.004) but not the SF algorithm (20.0 +/- 10.6) (P =.11). The depth of defects measured by the SS (220.4 +/- 108.0 dB) and SF (219.8 +/- 101.3 dB) algorithms was significantly shallower compared with that measured by the FT algorithm (152.3 +/- 79.1 dB) (P<.001). There were no significant differences in Hodapp-Anderson-Parrish severity scores among algorithms (P =.12). CONCLUSIONS: Glaucomatous defects are measured significantly shallower using the new SITA algorithms but are approximately the same size and severity compared with FT measurements. Care should be taken when using threshold values to compare glaucomatous defects in a patient when converting from FT to SITA algorithms.

Sensitivity and specificity of the Swedish interactive threshold algorithm for glaucomatous visual field defects.

PURPOSE: To determine the sensitivity and specificity of two new visual field algorithms in detecting glaucomatous visual field defects: (1) Swedish interactive threshold algorithm (SITA) standard and (2) SITA fast. DESIGN: Prospective observational case series. PARTICIPANTS: Ninety normal subjects and 82 glaucoma patients. TESTING: Central 30 degrees fields were performed with the Humphrey visual field analyzer 30-2 program (Humphrey Systems, Dublin, CA) using full threshold, SITA standard, and SITA fast algorithms on the same day for two or more sessions within a 1-month period. MAIN OUTCOME MEASURES: Sensitivity and specificity in detecting glaucomatous visual field defects with SITA standard and SITA fast using full threshold testing as the reference standard. RESULTS: The sensitivity of SITA standard and SITA fast in detecting glaucomatous defects overall was 98% and 95%, respectively. In the subset of mild glaucomatous field defects (26 patients), sensitivity of SITA standard was 92% versus 85% with SITA fast. Sensitivity was 100% for both algorithms in moderate to severe glaucomatous defects. Specificity for glaucoma defects using SITA standard and SITA fast was 96% for both algorithms. SITA standard reduced test-taking time from full threshold by 52% in normal subjects and 47% in glaucoma patients (P < 0.001). SITA fast reduced test-taking time by 72% in normal subjects and 65% in glaucoma patients (P < 0.001). Mean deviation values were 0.4 dB and 0.8 dB better in SITA standard and SITA fast fields, respectively, in normal subjects (P < 0.001), and 0.7 dB and 1.2 dB in SITA standard and SITA fast fields, respectively, in glaucoma patients (P < 0.001) compared with full threshold values. CONCLUSIONS: The new algorithms for measuring visual fields, SITA standard and SITA fast, have excellent sensitivity and specificity for glaucomatous visual field loss with considerable savings in time.