Marvin Lee

Relationship between ocular pulse amplitude and glaucomatous central visual field defect in normal-tension glaucoma.

Purpose:To investigate the relationship between central visual field (VF) defects and ocular pulse amplitude (OPA) in early normal-tension glaucoma (NTG). Patients and Methods:This retrospective study included 100 eyes of 100 subjects: 54 NTG patients whose mean deviations were better than −7.00 dB and 46 normal subjects. OPA was measured by dynamic contour tonometry. NTG patients were divided into 2 subgroups according to VF tests: the central VF-invading and the central VF-sparing groups. Ocular parameters including OPA, intraocular pressure (IOP), and indices of VF tests were analyzed in glaucoma patients and normal subjects. Results:There was no difference in the OPA between the NTG and normal groups. However, IOP and OPA of the central VF-invading group (14.4±2.87 and 2.9±0.78 mm Hg) were higher than those of the central VF-sparing group (12.7±2.52 and 2.0±0.80 mm Hg; P=0.025 and P<0.001, respectively). OPA, but not IOP, showed a positive correlation with the VF test indices that represented central field defects (r=0.494, P<0.001). Conclusions:Increased OPA was related to more centrally located VF defects in NTG patients with mild VF defects.

Burst-shot infrared digital photography to determine scotopic pupil diameter

PURPOSE: To evaluate the usefulness of infrared digital photography for determining scotopic pupil size by comparing infrared digital photography with a Colvard pupillometer (Oasis Medical). SETTING: Department of Ophthalmology, Ajou University School of Medicine, Suwon, Korea. METHODS: Scotopic pupil size in 50 eyes of 25 healthy individuals was measured with a Colvard pupillometer and a digital camera (DSC‐F828) using infrared burst shots after 5 minutes of dark adaptation. Measurements were performed by 2 independent examiners (E1 and E2). The digital photograph images were read using the ruler function of Adobe Photoshop 7.0 by 2 independent readers (R1 and R2). Agreement and repeatability were analyzed using the comparison method described by Bland and Altman. RESULTS: The mean scotopic pupil diameter measured using the Colvard pupillometer was 6.69 mm ± 0.78 (SD) (E1) and 6.70 ± 0.71 mm (E2). The mean scotopic pupil diameter measured from the digital photograph images was 6.67 ± 0.75 mm (E1) and 6.66 ± 0.78 mm (E2). The mean difference between E1 and E2 with both devices was small; however, the result with the infrared digital camera was marginally smaller than with the Colvard pupillometer. The limits of agreement were –0.01 ± 0.70 mm with the Colvard pupillometer and 0.01 ± 0.20 mm with the digital photograph image. The digital photograph image showed better agreement. The coefficient of interrater repeatability was smaller for the digital photograph image (0.39) than for the Colvard pupillometer (0.70). CONCLUSIONS: Scotopic pupil measurement using an infrared digital camera with a burst shot had good agreement with the Colvard pupillometer and better repeatability. The infrared digital camera is less expensive, and pupil unrest can be overcome by taking serial images.

Comparison of Disc Analysis Algorithms Provided by Cirrus OCT and Stereo Optic-disc Photography in Normal and Open Angle Glaucoma Patients

Abstract Purpose: To compare optic nerve head (ONH) parameters obtained by semi-automated disc analysis of stereo optic-disc photography (ODP) with those by spectral domain optical coherence tomography (SD-OCT) regarding their reproducibility, agreement and relationship with the retinal nerve fiber layer (RNFL) thickness. Patients and methods: In this cross-sectional retrospective study, 91 eyes (50 normal and 41 with open angle glaucoma) from 47 patients were examined. ONH parameters were obtained by ODP and SD-OCT. Agreement and reproducibility were assessed by intra-class correlation coefficients (ICCs). Inter-device agreement and precision were also evaluated. The structural factors related to the ONH measurements by both instruments and the disparity between the measurements were evaluated by the generalized estimating equation model. Results: ODP showed good intra-reader and inter-reader reproducibility, comparable to that of SD-OCT (ICC: >0.970). Disc area (DA) (ICC: 0.950) showed better inter-device agreement than rim area (RA) (ICC: 0.859). RNFL thickness was correlated with RA, but not with DA, for both devices. SD-OCT RA showed significant correlation with RNFL thickness in both the normal and glaucoma groups, whereas ODP RA correlated with RNFL only in the glaucoma group. The measurement disparity between the devices was influenced by the DA in both groups. The inter-device difference in RA was not correlated with RA, but instead with the RNFL thickness in the glaucoma group. Conclusion: ONH parameters obtained by semi-automated algorithms of ODP showed excellent reproducibility and good agreement with those measured by SD-OCT. SD-OCT RA was a better indicator of RNFL thickness, compared with ODP RA for both normal patients and glaucoma patients; however, the inter-device disparity of the RA was less in glaucoma patients who had a thinner RNFL.

Comparison of Event-Based Methods Using Optical Coherence Tomography and Automated Perimetry to Detect the Progression of Glaucoma in Patients with Open-Angle Glaucoma

Background/Aims: To compare event-based methods for estimating the incidence of glaucoma progression using optical coherence tomography (OCT) and automated perimetry and to assess agreement between structural and functional tests for detecting glaucoma progression. Methods: Functional progression of glaucoma was estimated by guided progression analysis (GPA) using a Humphrey field analyzer (HFA), and structural progression was assessed by OCT and defined as the decrease in retinal nerve fiber layer thickness based on test-retest variability data of previous reports on clock-hour and quadrant maps. The level of agreement between structural and functional progression was evaluated using kappa statistics. Results: Fifty eyes of 50 patients with open-angle glaucoma were enrolled in this retrospective study. The incidence of visual field progression estimated by GPA was 18%. The occurrence of structural progression assessed by OCT ranged from 18 to 68%. The more stringent OCT progression criterion using a quadrant map showed the best agreement with HFA GPA (ĸ = 0.423) and detected perimetric progression with high specificity, while the less stringent OCT criterion considering any clock hour showed the lowest agreement with functional progression (ĸ = 0.098). Conclusion: OCT progression criteria based on test-retest variability showed moderate agreement with perimetric progression, and more stringent criteria showed better agreement with functional progression than less stringent ones.

Agreement of New Automated Matched Alternation Flicker using Undilated Fundus Photography for the Detection of Glaucomatous Structural Change

ABSTRACT Purpose: To determine the agreement among glaucoma experts and general ophthalmologists regarding detection of glaucomatous structural changes using a new automated matched alternation flicker (AMAF) method with fundus photographs (FPs) of undilated eyes. Methods: Sixty-six pairs of FPs of normal tension glaucoma patients were collected. FPs were taken at intervals of more than 12 months. Alternating flicker images were created using a new AMAF application. In a blinded manner, two glaucoma experts and two general ophthalmologists compared the presence of glaucomatous structural changes using either the AMAF method or the side-by-side comparison method. The interobserver and intraobserver agreements were compared using the Bland and Altman plot analysis. Results: The glaucoma experts detected more glaucoma progression using the AMAF method (average, 50.7%) compared with the side-by-side method (average, 32.5%). General ophthalmologists detected more glaucomatous progression with the AMAF method (average, 40.9%) than with the side-by-side method (average, 25.0%). The AMAF method showed fair to substantial interreader agreement (k = 0.511–0.724) and fair to perfect intrareader agreement (k = 0.631–0.943). Interreader and intrareader agreements using the AMAF method were better for the glaucoma experts compared with the general ophthalmologists. Conclusions: The AMAF method showed more changes in FPs than the classical side-by-side comparison method. Regarding inter- and intrareader agreements, agreement for the glaucoma experts was best using the AMAF method, but for the general ophthalmologists agreement was best using the side-by-side comparison method.