Kyoung Sub Lee

Detection of Glaucomatous Progression by Spectral-Domain Optical Coherence Tomography

PURPOSEnTo compare the rate of change of circumpapillary retinal nerve fiber layer (cRNFL) thickness, macular volume and thickness, and optic nerve head (ONH) parameters assessed using spectral-domain optical coherence tomography (SD-OCT) between eyes with progressing and nonprogressing glaucoma.nnnDESIGNnLongitudinal, observational study.nnnPARTICIPANTSnTwo hundred seventy-nine eyes from 162 glaucoma patients followed for an average of 2.2 years.nnnMETHODSnEyes were classified as progressors and nonprogressors according to assessment of optic disc and RNFL photographs and visual field progression analysis. Linear mixed effects models were used to evaluate the overall rate of change of cRNFL thickness, macular volume and thickness, and ONH parameters after adjustment for age, spherical equivalent, signal strength, and baseline SD-OCT measurements.nnnMAIN OUTCOME MEASURESnThe rate of change of cRNFL thickness, macular volume, and thickness and ONH parameters.nnnRESULTSnSixty-three eyes (22.6%) from 52 subjects were identified as progressors. Average, inferior quadrant, and 6- and 7-oclock sector cRNFL thickness decreased faster in progressors than in nonprogressors (-1.26 vs -0.94, -2.47 vs -1.75, -3.60 vs -2.52, and -2.77 vs -1.51 μm/year, respectively; all P<0.05). The ONH rim area decreased faster, and average and vertical cup-to-disc ratio increased faster in progressors than in nonprogressors (-0.016 vs -0.006 mm(2)/year, and 0.004 vs 0.002 and 0.006 vs 0.004 per year, respectively; all P<0.05). Macular cube volume and the thickness of temporal outer and inferior inner macular sectors decreased faster in progressors than in nonprogressors (-0.068 vs -0.048 mm(3)/year, and -2.27 vs -1.67 and -2.51 vs -1.73 μm/year, respectively; all P<0.05).nnnCONCLUSIONSnSerial measurement of parameters in all 3 areas (cRNFL, macula, and ONH) by SD-OCT may permit identification of progression in glaucomatous eyes.nnnFINANCIAL DISCLOSURE(S)nThe authors have no proprietary or commercial interest in any of the materials discussed in this article.

Evaluation of Lamina Cribrosa in Pseudoexfoliation Syndrome Using Spectral-Domain Optical Coherence Tomography Enhanced Depth Imaging

PURPOSEnTo evaluate the features of the lamina cribrosa (LC) in pseudoexfoliation glaucoma (PXG) patients using enhanced depth imaging (EDI) of spectral-domain optical coherence tomography (SD OCT). The results were compared with those of patients with primary open-angle glaucoma (POAG).nnnDESIGNnCross-sectional study.nnnPARTICIPANTSnPatients with PXG (n = 21) and POAG (n = 35) matched for age and visual field mean deviation (VF MD).nnnMETHODSnParticipants were imaged using SD OCT. Lamina cribrosa thickness (LT) and anterior lamina cribrosa depth (ALD) were determined at 3 areas (mid superior, center, and mid inferior) by 2 examiners using an EDI mode of the optic nerve head.nnnMAIN OUTCOME MEASURESnThe LT and ALD were compared between PXG and POAG eyes.nnnRESULTSnMean ± standard deviation baseline untreated intraocular pressure was not significantly different between the 2 groups (PXG, 18.3 ± 8.2 mmHg; POAG, 15.3 ± 3.4 mmHg; P = 0.310). The mean VF MD was -12.7 ± 9.0 dB in the PXG group versus -11.6 ± 9.1 dB in the POAG group (P = 0.643). When compared with the POAG group, the PXG group demonstrated a significantly thinner LT in all 3 areas and a thinner mean LT (133.4 ± 14.5 μm in the POAG group vs. 121.3 ± 13.0 μm in the PXG group; P<0.001). Anterior lamina cribrosa depth did not demonstrate a significant difference in any of the 3 areas between both groups (mean ALD, 324.3 ± 91.9 μm in the POAG group vs. 358.7 ± 142.7 μm in the PXG group; P = 0.470). Of 21 eyes in the PXG group, 9 eyes demonstrated a unilateral clinical presentation. When we compared the PXG eyes and the apparently normal-looking fellow eyes of those 9 eyes, neither the LT nor ALD demonstrated a significant difference (P = 0.223 and P = 0.079, respectively).nnnCONCLUSIONSnEyes with PXG demonstrate a thinner LC compared with POAG eyes at similar levels of glaucoma severity.nnnFINANCIAL DISCLOSURE(S)nThe author(s) have no proprietary or commercial interest in any materials discussed in this article.

Optic Disc Torsion Presenting as Unilateral Glaucomatous-Appearing Visual Field Defect in Young Myopic Korean Eyes

PURPOSEnTo investigate the ocular features of companion eyes in an attempt to find eye-related factors that are associated with unilateral glaucomatous-appearing visual field (VF) defects in young myopic subjects.nnnDESIGNnRetrospective, cross-sectional study.nnnPARTICIPANTSnThirty-nine patients (age range, 20-50 years) with unilateral glaucomatous-appearing VF defect and myopia.nnnMETHODSnA comparison was performed between VF-affected eyes and contralateral normal eyes. Optic disc torsion and tilt ratio were measured from disc photographs. Logistic regression analysis and linear regression analysis were performed to investigate various ocular parameters, including torsion degree and tilt ratio, that may be associated with the presence and severity of VF defect.nnnMAIN OUTCOME MEASURESnTorsion degree, tilt ratio, and the severity of VF defect.nnnRESULTSnOptic disc torsion degree (16.63±9.78°) of VF-affected eyes was statistically greater than that of the normal contralateral eyes (8.69±7.28°; P<0.001). Optic disc torsion was more prevalent in VF-affected eyes (66.6%) than in normal contralateral eyes (15.3%; P<0.001). In the multivariate analysis, the degree of optic disc torsion was associated significantly with the presence of VF defect (P = 0.005). The torsion degree (P = 0.006) and retinal nerve fiber layer thickness (P = 0.004) were associated significantly with the severity of VF defect.nnnCONCLUSIONSnThe prevalence and degree of optic disc torsion in the VF-affected eyes were significantly greater than those of contralateral normal eyes in unilateral, young, myopic patients with glaucomatous-appearing VF defect. Optic disc torsion should be considered in the presence of unilateral glaucomatous-appearing VF defect in young myopic eyes.

Residual anterior chamber angle closure in narrow-angle eyes following laser peripheral iridotomy: anterior segment optical coherence tomography quantitative study

PurposeTo study quantitative changes in anterior chamber angle (ACA) after laser peripheral iridotomy (LPI) in narrow-angle eyes using anterior segment optical coherence tomography (AS-OCT).MethodsEighteen subjects with narrow angles were imaged with AS-OCT for determining test–retest variability. Forty-six participants with narrow angles were scanned with AS-OCT before LPI and 4 weeks after LPI. The presence of ACA closure by both AS-OCT imaging and gonioscopy was compared before and after LPI. Three ACA parameters by AS-OCT, angle opening distance at 500 μm (AOD500), trabecular-ris space area at 500 μm (TISA500) and angle recess area at 500 μm (ARA500), at both nasal and temporal quadrants were incorporated for analysis. The increment of ACA parameters defined as exceeding the 95% confidence interval of test–retest variability was assessed after LPI.ResultsAll 3 parameters obtained from the 18 eyes showed good measurement reproducibility (intraclass correlation coefficient 0.850–0.979). Persistent angle closure was detected in 23.9% of eyes by gonioscopy, and in 34.8% of eyes by AS-OCT images at temporal quadrant after LPI. When assessed by measurement variability criteria, the percentage of eyes that showed no significant change in ACA parameters ranged from 23.9% to 45.7% after LPI.ConclusionsOverall, ACA parameters changed significantly after LPI; however, when assessed by AS-OCT, ACA remained unchanged in some narrow-angle eyes despite LPI. Our findings suggest that multiple causes other than pupillary block may contribute to narrow-angle closure following LPI.

Relationship Between 24-Hour Mean Ocular Perfusion Pressure Fluctuation and Rate of Paracentral Visual Field Progression in Normal-Tension Glaucoma

PURPOSEnTo investigate the relationship between unstable mean ocular perfusion pressure (MOPP) and the rate of paracentral visual field (PVF) progression in patients with medically treated normal-tension glaucoma (NTG).nnnMETHODSnThe data of 157 eyes of 122 patients with NTG who were followed for more than 6 years (mean follow-up, 8.7 years ± 12.6 months) and had more than 5 reliable standard visual field (VF) tests were analyzed retrospectively. Groups in the highest, middle, and lowest tertiles of 24-hour MOPP fluctuation (HMF, MMF, and LMF, respectively) were compared in terms of rates of change of mean thresholds in the central 10° (PVF), 10° to 24°, and global areas by using a linear mixed model. Clinical factors associated with rapid PVF progression were also investigated.nnnRESULTSnThe LMF and HMF groups did not differ significantly in the mean global rate of VF changes (-0.52 vs. -0.71 dB/y; P = 0.07). The HMF group had a significantly faster progression of VF defects in the central 10° area than the LMF group (-1.02 vs. -0.54 dB/y; P < 0.001) but did not differ in terms of progression of VF defects in the peripheral 10° to 24° area (-0.39 vs. -0.495 dB/y; P = 0.425). PVF progression was significantly associated with 24-hour MOPP fluctuation (β = -0.31, P < 0.001) and VF damage severity at initial presentation (β = 0.134, P = 0.011).nnnCONCLUSIONSnMedically treated NTG eyes with greater 24-hour MOPP fluctuations (HMF) had faster PVF defect progression than eyes with stable 24-hour MOPP (LMF). Twenty-four hour MOPP fluctuation associated significantly with PVF progression velocity.

Assessment of narrow angles by gonioscopy, Van Herick method and anterior segment optical coherence tomography

PurposeTo evaluate anterior chamber (AC) angles using gonioscopy, Van Herick technique and anterior segment optical coherence tomography (AS-OCT).MethodsOne hundred forty-eight consecutive subjects were enrolled. The agreement between any two of three diagnostic methods, gonioscopy, AS-OCT and Van Herick, was calculated in narrow-angle patients. The area under receiver-operating characteristic curves (AUC) for discriminating between narrow and open angles determined by gonioscopy was calculated in all participants for AS-OCT parameter angle opening distance (AOD), angle recess area, trabecular iris surface area and anterior chamber depth (ACD). As a subgroup analysis, capability of AS-OCT parameters for detecting angle closure defined by AS-OCT was assessed in narrow-angle patients.ResultsThe agreement between the Van Herick method and gonioscopy in detecting angle closure was excellent in narrow angles (κ = 0.80, temporal; κ = 0.82, nasal). However, agreement between gonioscopy and AS-OCT and between the Van Herick method and AS-OCT was poor (κ = 0.11–0.16). Discrimination capability of AS-OCT parameters between open and narrow angles determined by gonioscopy was excellent for all AS-OCT parameters (AUC, temporal: AOD500 = 0.96, nasal: AOD500 = 0.99). The AUCs for detecting angle closure defined by AS-OCT image in narrow angle subjects was good for all AS-OCT parameters (AUC, 0.80–0.94) except for ACD (temporal: ACD = 0.70, nasal: ACD = 0.63).ConclusionAssessment of narrow angles by gonioscopy and the Van Herick technique showed good agreement, but both measurements revealed poor agreement with AS-OCT. The angle closure detection capability of AS-OCT parameters was excellent; however, it was slightly lower in ACD.

A hierarchical cluster analysis of primary angle closure classification using anterior segment optical coherence tomography parameters.

PURPOSEnTo investigate the possibility of classifying angle closure eyes in terms of features provided by anterior segment optical coherence tomography (AS OCT).nnnMETHODSnAngle closure (primary angle closure [PAC] or PAC glaucoma [PACG]) eyes diagnosed by gonioscopy were imaged using AS OCT under the same lighting conditions. Anterior chamber depth (ACD), anterior chamber width (ACW), iris cross-sectional area (IA), iris thickness at 750 μm from the scleral spur (IT750), iris curvature (IC), lens vault (LV), and anterior chamber area (ACA) were determined using Image J software (ver. 1.44). A hierarchical cluster analysis using Wards method was performed using AS parameters obtained by AS OCT and axial length (AXL).nnnRESULTSnA hierarchical cluster analysis was performed on 166 angle closure eyes and produced two clusters. The first cluster (84 eyes) was characterized by higher ACD (2.24 mm), higher ACA (12.5 mm(2)), higher IT750 (0.44 mm), higher ACW (11.2 mm), lower LV (0.85 mm), and higher AXL (23.5 mm) compared with the second cluster (82 eyes, 1.82 mm, 9.5 mm(2), 0.38 mm, 10.8 mm, 1.1 mm, and 22.8 mm, respectively). The second cluster had essentially higher LV and lower ACA than the first cluster. Most parameters were significantly different between two clusters except IC (P = 0.76).nnnCONCLUSIONSnOur hierarchical cluster analysis indicated two clusters with quite different features existed in our total angle closure population. Our results suggest the possibility of subclassifying angle closure eyes according to AS OCT parameters.

Baseline Anterior Segment Parameters Associated with the Long-term Outcome of Laser Peripheral Iridotomy

Abstract Purpose: To investigate the baseline anterior segment (AS) parameters determined by AS optical coherence tomography (AS OCT) in the prediction of long-term outcome of laser peripheral iridotomy (LPI) in primary angle closure suspect (PACS) eyes Methods: Participants were imaged at pre-LPI and at 2 weeks and 3 years post-LPI using AS OCT. Based on these images, anterior chamber depth (ACD), iris curvature (IC), anterior chamber width (ACW), iris thickness at 750u2009µm from the scleral spur (IT750), lens vault (LV), and iris area (IA) were estimated using the Image J software (version 1.46). Proportional change (%) in angle opening distance at 750u2009µm from the scleral spur (AOD750) was used as an outcome measure for LPI. Univariate and multivariate regression analyses were performed to evaluate baseline AS parameters associated with changes in AOD750. Results: A total of 39 PACS eyes were included. At 2 weeks post-LPI, thinner IT750 (pu2009=u20090.006) and less AOD750 (pu2009<u20090.001) at baseline were related to a greater AOD750 change. When assessed at 3 years post-LPI, thinner IT750 (pu2009=u20090.039) and less AOD750 (pu2009=u20090.003) at baseline were associated with a greater AOD750 change. Conclusions: Thin peripheral iris and less AOD750 at baseline were associated with greater changes in longitudinal assessment after LPI. PACS eyes with thick peripheral iris at baseline showed less AOD750 change at both early and late follow up after LPI; therefore, such eyes should be followed with caution despite successful LPI.

In vivo validation of the new Tonopen AVIA tonometer using manometers placed in the anterior chamber and the vitreous cavity under various vitreous conditions.

Abstract Purpose: To validate intraocular pressure (IOP) measurements using the new Tonopen AVIA® tonometer by comparing values obtained with those measured by manometers placed in the anterior chamber (AC) and the vitreous cavity (VC). Materials and Methods: Seventy-nine consecutive patients awaiting phacovitrectomy for epiretinal membrane (ERM) or macular hole (MH) (nu2009=u200929), vitreous hemorrhage (DMVH) (nu2009=u200927) or silicone oil removal (nu2009=u200923) were included in this prospective observational study. A clinician masked to patient information performed a complete ophthalmologic examination, including measurements of corneal thickness (CT), AC depth and axial length. Another examiner simultaneously measured conventional IOP using the Tonopen AVIA® (TIOP) and AC and VC IOPs (ACIOP and VCIOP) using two transducers. Results: The mean TIOP, ACIOP and VCIOP were 16.1u2009±u20093.8, 16.1u2009±u20094.4 and 15.5u2009±u20094.6u2009mmHg, respectively. There was a good agreement between the TIOP and ACIOP; however, the agreement between TIOP and VCIOP was relatively poor in subgroup analysis. VCIOP was significantly higher than TIOP in the ERM and MH group, with a mean difference of 1.0u2009mmHg (pu2009=u20090.042); however, they were significantly lower in the DMVH group, with a mean difference of −0.7u2009mmHg (pu2009=u20090.026) and in the silicone oil group (mean difference, −2.3u2009mmHg) (pu2009<u20090.0001). In multivariate analysis, TIOP correlated significantly only with CT (pu2009<u20090.037) and increased by 2.7u2009mmHg per 100u2009μm increase in CT. Conclusions: IOP measurements using the Tonopen AVIA® tonometer showed good agreement with ACIOP values, although TIOP measurements were affected by CT. However, the VCIOP values using the transducer may have over- or underestimated IOP relative to TIOP and ACIOP under various vitreous conditions. Further validation of VCIOP using a cannular type of manometer should be considered.