Tae Woo Kim

Lamina cribrosa thickness is not correlated with central corneal thickness or axial length in healthy eyes: central corneal thickness, axial length, and lamina cribrosa thickness.

BackgroundThe aim of this study was to determine the relationship of the central corneal thickness (CCT) and axial length (AXL) with the central lamina cribrosa thickness (LCT) in healthy human eyes.MethodsThis was a prospective observational case series. The optic discs of 189 eyes from 100 healthy subjects with a refractive error smaller than −8 diopters were scanned using enhanced-depth imaging spectral-domain optical coherence tomography (Spectralis OCT, Heidelberg Engineering, Heidelberg, Germany). The thickness of the lamina cribrosa (LC) was measured on B-scan images obtained at the center of the optic nerve head. A linear mixed-effects model was used to determine the factors associated with LCT, taking into account clustering of eyes within subjects.ResultsThe thickness of the central LC was 273.19u2009±u200934.74xa0μm (mean ± SD; range, 173.73–367.94xa0μm). Multivariate analysis revealed a significant influence of older age on increased central LCT (pu2009=u20090.001). There was no significant association between central LCT and either CCT or AXL.ConclusionsIn this study, the central LCT increased significantly with older age in healthy human eyes. Neither CCT nor AXL was significantly associated with the central LCT in healthy human eyes with a spherical equivalent within the range from −7.0 to +3.0 diopters.

An unexpectedly low Stratus optical coherence tomography false-positive rate in the non-nasal quadrants of Asian eyes: indirect evidence of differing retinal nerve fibre layer thickness profiles according to ethnicity

Aims: To determine the frequency distribution of false-positive Stratus optical coherence tomography (OCT) results of healthy eyes in terms of peripapillary location. Methods: One eye of each of 137 healthy Korean subjects was included. The false-positive rates (FPRs) relating to retinal nerve fibre layer (RNFL) thickness parameters were determined. Results: Of the 12 clock-hour positions, the 2 and 4 o’clock positions showed the highest FPRs of 5.1% and 4.4%, respectively, and 7, 8 and 11 o’clock had the lowest FPRs of 0% at <5% level. At <1% level, 2 and 6 o’clock had an FPR of 0.7%, while the FPR was 0% for all other clock-hours. The FPRs for quadrant thicknesses at <5% level were: 0.7% for temporal; 0% for superior; 5.1% for nasal; and 2.2% for inferior. At <1% level, the inferior showed the highest FPR of 0.7%, and the other three quadrants 0%. According to line graph analysis, the 80–120 test point sections had FPRs of 4.4–6.6%, while the 0–40 and 210–256 sections were 0–0.7% at <5% level. At <1% level, the 40–60, 90–110 and 200–210 sections had 0.7%, 190–200 section 1.5%, and all other sections 0%. Conclusion: The FPR for the non-nasal region was much lower than expected at <5% level. Given that the current OCT normative database is based on a largely non-Asian population, these findings suggest that RNFL thickness profiles may differ according to ethnicity.

Pseudophakic Macular Edema in Primary Open-Angle Glaucoma: A Prospective Study Using Spectral-Domain Optical Coherence Tomography

PURPOSEnTo determine the incidence of and risk factors for pseudophakic macular edema (PME) after uncomplicated cataract surgery in primary open-angle glaucoma (POAG) using spectral-domain optical coherence tomography (SDOCT).nnnDESIGNnCohort study.nnnMETHODSnMacular retinal thickness was evaluated using SDOCT at 1xa0week before surgery and at 1, 3, 6, and 12xa0months postoperatively, in 70 POAG and 68 control eyes. Forty-three healthy subjects without impaired vision or cystoid PME were recruited separately as pilot samples to define significant PME. Significant PME was defined as an increase in the average thickness exceeding the meanxa0+ 3 standard deviations of the increase shown in the pilot samples.nnnRESULTSnSignificant PME (increase in the foveal 3-mm zone thickness of >19.5xa0μm) was observed in 31 (44%) eyes with POAG and in 14 (21%) control eyes (Pxa0=xa0.003). The extent of PME was maximal at 3xa0months postoperatively and decreased gradually until 12xa0months. Regression tree analysis revealed that the risk of PME was the greatest in the POAG group using prostaglandin analogue (PGA) (odds ratio [OR]xa0= 5.51), followed by POAG not using PGA (ORxa0= 1.70), and control group (ORxa0= 1.0). Risk factors for PME were younger age in all groups (ORxa0= 1.07), systemic hypertension in PGA users (ORxa0= 6.42), higher untreated IOP in PGA nonusers (ORxa0= 1.09) and male sex (ORxa0= 14.06) and diabetes mellitus (ORxa0= 16.71) in the control group.nnnCONCLUSIONSnThe incidence of PME as observed by SDOCT was higher than previously reported after uncomplicated cataract surgery. Eyes with POAG were at greater risk for PME, which was mainly associated with perioperative PGA use.

Comparison of ability of time-domain and spectral-domain optical coherence tomography to detect diffuse retinal nerve fiber layer atrophy

AbstractPurposeOur aim was to evaluate and compare diagnostic capabilities of time-domain (Stratus) and spectral-domain (Cirrus) optical coherence tomography (OCT) to detect diffuse retinal nerve fiber layer (RNFL) atrophy.MethodsThis study assessed 101 eyes from 101 glaucoma patients with diffuse RNFL atrophy and 101 eyes from 101 age-matched healthy individuals. Two experienced glaucoma specialists graded red-free RNFL photographs of eyes with diffuse RNFL atrophy using a four-level grading system. The area under the receiver operating characteristic curves (AUC) of normal eyes was compared with that of eyes with diffuse atrophy. Sensitivity and specificity of each OCT device were calculated on the basis of its internal normative database.ResultsThe largest AUC for Stratus and Cirrus were obtained for average RNFL thicknesses (0.96 and 0.94, respectively). Comparison of the AUC with different RNFL atrophy grades revealed no significant difference between the two OCT devices. Using an internal normative database at a <5xa0% level, the overall sensitivity of Stratus ranged from 58.0 to 84.0xa0%, whereas that of Cirrus ranged from 75.0 to 87.0xa0%. According to the normative database, the highest Stratus sensitivity was obtained with the temporal–superior–nasal–inferior–temporal (TSNIT) thickness graph, and the highest Cirrus sensitivity with the TSNIT thickness graph and the deviation map.ConclusionsThe AUC obtained from Cirrus were comparable with those from Stratus. On the basis of their normative databases, these devices had similar diagnostic accuracy. Our results suggest that the diagnostic capabilities of the two instruments to detect diffuse RNFL atrophy are similar.n

Factors associated with the retinal nerve fiber layer loss after acute primary angle closure: A prospective EDI-OCT study

Purpose To determine the factors associated with retinal nerve fiber layer (RNFL) loss in eyes with acute primary angle-closure (APAC), particularly focusing on the influence of the change in the anterior lamina cribrosa surface depth (LCD). Methods After the initial presentation, 30 eyes with unilateral APAC were followed up at the following specific time points over a 12-month period: 1 week, 1~2 months, 2~3 months, 5~6 months, and 11~12 months. These follow-ups involved intraocular pressure measurements, enhanced depth-imaging spectral-domain optical coherence tomography (SD-OCT) scanning of the optic disc, and measurements of the circumpapillary RNFL thickness. The prelaminar tissue thickness (PLT) and LCD were determined in the SD-OCT images obtained at each follow-up visit. Results Repeated measures analysis of variance revealed a significant pattern of decrease in the global RNFL thickness, PLT, and LCD (all p<0.001). The global RNFL thickness decreased continuously throughout the follow-up period, while the PLT decreased until 5~6 months and did not change thereafter. The LCD reduced until 2~3 months and then also remained steady. Multivariable regression analysis revealed that symptoms with a longer duration before receiving laser peripheral iridotomy (LI) (p = 0.049) and a larger LCD reduction (p = 0.034) were significant factors associated with the conversion to an abnormal RNFL thickness defined using OCT normative data. Conclusion Early short-term decreases in the PLT and LCD and overall long-term decrease in the peripapillary RNFL were observed during a 12-month follow-up after an APAC episode. A longer duration of symptoms before receiving LI treatment and larger LCD reduction during follow-up were associated with the progressive RNFL loss. The LCD reduction may indicate a prior presence of significant pressure-induced stress that had been imposed on the optic nerve head at the time of APAC episode. Glaucomatous progression should be suspected in eyes showing LCD reduction after the APAC remission.

Treatment patterns and medication adherence of patients with glaucoma in South Korea

Background/aims This study aimed to investigate treatment patterns and medication adherence of glaucoma. It also identified key factors associated with non-adherence. Methods It was a cross-sectional, observational study. Patients who use eye-drops for ≤2u2005years were recruited at 15 eye clinics from March to November 2013. Data were collected through self-administered questionnaires and medical chart review. Medication adherence was evaluated using patients’ self-report on pill count and defined as patients’ administering drug for ≥80% of prescribed days. Medication adherence rate was calculated by dividing actual number of administration from total prescribed number of administration for 7u2005days. Patients whose self-reported prescription was different from total daily doses of physicians prescription were considered as non-adherent. Results A total of 1050 patients included, and medication adherence rate was evaluated in 1046 patients whose verification of adherence was available. Of the total, 27.4% were non-adherent, and the medication adherence rates of the total, the adherent, and the non-adherent were 90.6±17.8%, 96.8±5.5% and 56.6±24.7%, respectively. The most commonly used medication was prostaglandin (PGA) alone and the second was combination of two-class (β-blocker and carbonic anhydrase inhibitor (CAI)) and three-class combination of PGA, β-blocker and CAI followed. In multivariate analysis, the risk of non-adherence was 1.466 times greater in males than in females (95% CI 1.106 to 1.943) and 1.328-fold greater as the daily number of administration was increased (95% CI 1.186 to 1.487). Conclusion Approximately, one-third of the patients were non-adherent, and males and increased daily number of administration were associated with non-adherence. It highlights that more systematic treatment strategies should be considered for better medication adherence, leading to effective glaucoma management.