1.Corneal Thickness Measured by Dual Scheimpflug, Anterior Segment Optical Coherence Tomography, and Ultrasound Pachymetry.
Dong Wook KIM ; Ka Young YI ; Dong Gyu CHOI ; Young Joo SHIN
Journal of the Korean Ophthalmological Society 2012;53(10):1412-1418
PURPOSE: To compare central corneal thickness (CCT) as measured by dual rotating Scheimpflug camera (Galilei), anterior segment optical coherence tomography (AS-OCT), and ultrasound pachymetry (USP). METHODS: The measurements of CCT using a dual rotating Scheimpflug camera, AS-OCT, and USP in 40 eyes of 20 healthy subjects were compared. RESULTS: The average measurements of CCT by dual rotating Scheimpflug camera, AS-OCT, and USP were 538.10 +/- 31.36 microm, 536.20 +/- 31.21 microm, and 541.93 +/- 34.93 microm, respectively. The CCT measurement by USP was statistically significantly thicker than by the dual rotating Scheimpflug camera and AS-OCT (p = 0.017, p = 0.001, respectively). There was no significant difference between the dual rotating Scheimpflug camera and AS-OCT (p = 0.054). A significant linear correlation was observed between the dual rotating Scheimpflug camera, the AS-OCT, and the USP (r > 0.900, p < 0.001). CONCLUSIONS: The results of the 3 methods have significant correlation with each other, but the measurement by USP was significantly thicker than the dual rotating Scheimpflug camera and AS-OCT. Therefore, CCT should be interpreted in the context of the instrument used.
Eye
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Tomography, Optical Coherence
2.Comparison of the Efficacy between Time and Spectral Domain Optical Coherence Tomography for the Identification of Vitreomacular Interface.
Ja Young YOU ; Hyung Chan KIM ; Jun Woong MOON
Journal of the Korean Ophthalmological Society 2013;54(1):97-103
PURPOSE: To compare the efficacy of time domain (TD) and spectral domain (SD) optical coherence tomography (OCT) in determining vitreomacular interface (VMI). METHODS: VMIs were evaluated with TD and SD OCT images crossing the fovea horizontally in 69 eyes (mean age 52.7 +/- 15.4 years) and were classified as follows: (1) no vitreomacular separation (VMS), (2) incomplete VMS, and (3) unknown. RESULTS: In TD OCT, no VMS was observed in 2 eyes (2.9%), incomplete VMS in 2 eyes (2.9%), and unknown in 65 eyes (94.2%). In SD OCT, no VMS was observed in 31 eyes (45.0%), incomplete VMS in 13 eyes (18.8%), and unknown in 25 eyes (36.2%). In 31 eyes with no VMS on SD OCT, 29 eyes (93.5%) presented unknown on TD OCT (p<0.0001). In 13 eyes with incomplete VMS on SD OCT, 2 eyes (15.4%) showed incomplete VMS and 11 eyes (84.6%) showed unknown on TD OCT (p<0.0001). TD OCT was also non-informative in all 25 eyes with unknown on SD OCT. CONCLUSIONS: SD OCT allows better visualization of VMI than TD OCT, especially in patients with no VMS.
Humans
;
Tomography, Optical Coherence*
3.Angiographically minimal but functionally significant coronary lesion confirmed by optical coherence tomography.
Hyuck Jun YOON ; Yun Kyeong CHO ; Chang Wook NAM ; Kwon Bae KIM ; Seung Ho HUR
The Korean Journal of Internal Medicine 2016;31(4):807-808
No abstract available.
Tomography, Optical Coherence*
4.Repeatability and Agreement of Macular Thickness Measurement Using Time Domain OCT and Spectral Domain OCT in Normal Subjects.
Se Beum OH ; Won Bin CHO ; Jun Woong MOON ; Hyung Chan KIM
Journal of the Korean Ophthalmological Society 2009;50(5):710-716
PURPOSE:To compare the repeatability and agreement of macular thickness measurements using time domain (TD) optical coherence tomography (OCT) and spectral domain (SD) OCT in normal subjects. METHODS: Thirty-four normal subjects were included. Three consecutive macular measurements were taken with TD OCT and SD OCT. Total and regional macular thickness and total macular volume obtained by the two OCTs were compared. Within-subject standard deviation (Sw), coefficient of variation (CVw), and the intraclass correlation coefficient (ICC) were calculated to evaluate repeatability. The agreement was examined with Bland Altman plots. The correlation was also evaluated with Pearson correlation coefficients and multiple regression analysis. RESULTS: Sw for foveal thickness, total macular thickness, and total macular volume were 11.53 microm, 7.58 microm, and 0.48 mm3 for TD OCT and 6.69 microm, 2.55 microm, and 0.09 mm3 for SD OCT, respectively. The values for SD OCT were consistently lower, and this result was statistically significant. The range of the respective CVw and ICC values were 1.10~2.78% and 0.78~0.96% for TD OCT, and 0.29~0.94% and 0.92~0.99% for SD OCT, respectively. The SD OCT showed better repeatability for macular thickness measurements(all with p< or =0.001). The spans of 95% limits of agreement for foveal thickness, total macular thickness, and total macular volume were 67.94 microm, 29.01 microm, and 0.98 mm3, respectively. The Pearson correlation coefficient of foveal thickness, total macular thickness, and total macular volume between the two OCT's was statistically significant. CONCLUSIONS: Although both OCTs are reliable for macular thickness measurements, SD OCT shows better repeatability compared with TD OCT. Although macular thickness measurements obtained from the two OCTs can not be used interchangeably due to low agreement by different standards of measurement, there was a statistically significant correlation between the two OCT's.
Tomography, Optical Coherence
6.Changes in the retinal-nerve-fiber layer due to ethambutol toxic optic neuropathy
Richard G. Kho ; Heriberto G. Guballa ; John Michael L. Daquioag ; Christopher Napoleon G. Delos Reyes
Philippine Journal of Ophthalmology 2009;34(1):23-27
Objective: To describe changes in the retinal-nerve-fiber layer (RNFL) in patients diagnosed with ethambutol toxic optic neuropathy (ETON) using optical coherence tomography (OCT). Methods: Ophthalmological examinations were performed in 3 patients diagnosed with ETON. Visual acuity (VA), contrast sensitivity, color vision testing, slitlamp examination, applanation tonometry, dilated funduscopic examination, fundus and disc photography, automated perimetry and OCT were performed. Results: Three patients with ETON had VA ranging from 20/150 to counting fingers (CF). They were unable to resolve contrast sensitivity and discriminate fingers (CF). TWo patients with VA of CF in both eyes had RNFL thinning of 48.8% and 49.5%. A third patient 3 with VA of 20/150 in both eyes showed RNFL thickening of 14.10%. Conclusion: The results suggest that OCT may be useful ancillary procedure in early detection and monitoring of ophthalmological changes due to ETON.
Tomography Optical Coherence
7.Optical Coherence Tomography: Defined Plaque Erosion after Removal of a Coronary Guidewire
Sang Woong CHOI ; Seung Ho HUR ; Cheol Hyun LEE ; Yun Kyeong CHO ; Hyuck Jun YOON ; Chang Wook NAM ; Kwon Bae KIM
Korean Circulation Journal 2019;49(9):879-881
No abstract available.
Tomography, Optical Coherence
8.Determination of iridotrabecular contact using the anterior segment optical coherence tomography in lights-on and lights-off conditions
James Paul S. Gomez ; Edgar U. Leuenberger
Philippine Journal of Ophthalmology 2019;44(1):19-24
Objective:
To determine the presence of iridotrabecular contact (ITC) and compare the changes in anterior
chamber angle (ACA) measurements in room lights-on and lights-off conditions using the anterior segment
optical coherence tomography (AS-OCT) in eyes diagnosed as primary angle closure suspects (PACS) by
gonioscopy.
Methods:
This is a retrospective review of 144 eyes of 79 patients (70 females, 9 males) with PACS. All eyes
were imaged using the Visante® time-domain AS-OCT (Carl Zeiss Meditec, Dublin, CA). Each eye was
imaged twice; the first scan was done with the room lights on followed by a second scan done after turning
the room lights off for 2 minutes. The principal outcome measure was the presence of ITC in either lighting
condition. Other angle metrics that were assessed included anterior chamber depth (ACD), angle opening
distance (AOD), trabecular-iris space area (TISA), and scleral spur angle (SSA). Presence of ITC and differences
in the angle metrics between the 2 lighting conditions were then analyzed using the t-tests and logistic
regression.
Results:
ITC was present in 36.8% (53) of the study eyes. Twenty percent (20%) of the study eyes (29) did not
initially exhibit ITC in the lights-on phase but developed ITC when imaged with the lights off. Persistent ITC was
seen in 16.6% (24 eyes) in both lighting conditions. ITC occurred in 52.2% of the eyes with ACD less than 2.18
mm. Logistic regression showed that there is a 91% decrease in the odds of having ITC in lights-off condition for
every millimeter of ACD increase. Age was not associated with the occurrence of ITC in the lights-off condition. All other analyzed parameters decreased significantly in the lights-off condition (p<0.05) except for the ACD, nasal
TISA-500, and temporal SSA.
Conclusions
The presence of ITC is a well-established characteristic of eyes with angle closure. In eyes with
PACS, detection of ITC may be enhanced with AS-OCT imaging in lights-off condition.
Tomography, Optical Coherence
10.Diagnostic accuracy of the optical coherence tomography in assessing glaucoma among Filipinos. Part 1: Categorical outcomes based on a normative database
Noel de Jesus Atienza ; Joseph Anthony Tumbocon
Philippine Journal of Ophthalmology 2012;37(1):3-10
Objective:
To determine the accuracy of the optic nerve head (ONH) and retinal nerve fiber layer (RNFL)
parameters using the Stratus OCT in diagnosing glaucoma among Filipino patients and to determine the validity of
the OCT measurements compared with a reference standard.
Methods:
Glaucoma suspects were recruited consecutively from patients undergoing diagnostic tests. The results
of the Stratus OCT fast RNFL protocol were analyzed against the independent assessment by glaucoma experts
who were blinded. Outcomes included RNFL thickness values of ≤5 percentile and ≤1 percentile of the normative
database for each RNFL sector, quadrant, and for the average RNFL thickness. Estimates of diagnostic accuracy
with 95% confidence intervals were calculated.
Results:
A total of 119 subjects assessed as glaucoma and 397 subjects assessed as normal were included in the
analysis. Using the best categorical criterion for abnormality (average RNFL thickness of ≤1 percentile of the
normative database), the OCT had a specificity of 98% (95% CI 96 - 99) and a sensitivity of 37% (95% CI 28 - 46).
The criterion with the highest sensitivity was the presence of at least one sector with thickness at ≤5 percentile.
Conclusion
The Stratus OCT demonstrated a specificity of 98% and a sensitivity of 37% for the diagnosis of
glaucoma using as a criterion an average RNFL thickness of ≤1 percentile of the normative database. It was a poor
screening test for glaucoma suspects, although it showed some promise as a confirmatory test.
Glaucoma
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Tomography, Optical Coherence