ABSTRACT
AIM: To investigate the difference of macular thickness measurements between stratus optical coherence tomography (OCT) and Cirrus OCT (Carl Zeiss Meditec, Dublin, CA, USA) in the same myopic patient and to develop a conversion equation to interchange macular thickness obtained with these two OCT devices. METHODS: Eighty-nine healthy Chinese adults with spherical equivalent (SE) ranging from -1.13 D to -9.63 D were recruited. The macular thickness was measured by Cirrus OCT and Stratus OCT. The correlation between macular thickness and axial length and the agreement between two OCT measurements were evaluated. A formula was generated to interchange macular thickness obtained with two OCT devices. RESULTS: Average macular thickness measured with Stratus OCT (r=-0.280, P=0.008) and Cirrus OCT (r=-0.224, P=0.034) were found to be negatively correlated with axial length. No statistically significant correlation was found between axial length and central subfield macular thickness (CMT) measured with Stratus OCT (r=0.191, P=0.073) and Cirrus OCT (r=0.169, P=0.113). The mean CMT measured with Cirrus OCT was 53.63±7.94 µm thicker than with Stratus OCT. The formula CMTCirrus OCT=78.328+0.874×CMTStratus OCT was generated to interchange macular thickness obtained with two OCT devices. CONCLUSION: Macular thickness measured with Cirrus OCT were thicker than with Stratus OCT in myopic eyes. A formula can be used to interchange macular thickness measured with two OCT devices in myopic eyes. Studies with different OCT devices and larger samples are warranted to enable the comparison of macular values measured with different OCT devices.
ABSTRACT
PURPOSE: To evaluate and compare the diagnostic classification of retinal nerve fiber layer (RNFL) measurement between time-domain and spectral-domain optical coherence tomography (OCT) in myopic eyes. DESIGN: Prospective, observational study. METHODS: A total of 97 eyes from 97 healthy myopic subjects were included. The RNFL in each eye was imaged sequentially with the Stratus OCT and the Cirrus HD-OCT (Carl Zeiss Meditec). With reference to the built-in normative database, the number of abnormal diagnostic classifications (borderline or outside normal limits) in each OCT device was analyzed and compared using the likelihood ratio chi-square test. Multiple logistic regression analysis was performed to evaluate factors associated with abnormal diagnostic classification. RESULTS: The Cirrus HD-OCT classified a significantly higher percentage of eyes as outside normal limits/borderline in at least 1 clock hour (Stratus, 14.4%/24.8%; Cirrus, 21.6%/34.1%; all P < .01). RNFL measurement at 1 (23.6%) and 2 o'clock (23.5%) of all eyes was the most frequent location classified as abnormal by the Cirrus HD-OCT and the Stratus OCT, respectively. Eyes with smaller optic disc and longer axial length were more likely to have abnormal diagnostic classification. CONCLUSIONS: In myopic eyes, Cirrus HD-OCT was more likely to have abnormal diagnostic classification than the Stratus OCT.
Subject(s)
Glaucoma, Open-Angle/diagnosis , Myopia/complications , Nerve Fibers/pathology , Optic Disk/pathology , Optic Nerve Diseases/diagnosis , Retinal Ganglion Cells/pathology , Tomography, Optical Coherence/instrumentation , Adolescent , Adult , Female , Glaucoma, Open-Angle/classification , Glaucoma, Open-Angle/etiology , Humans , Male , Ophthalmoscopy , Optic Nerve Diseases/classification , Optic Nerve Diseases/etiology , Prospective Studies , Tomography, Optical Coherence/methods , Visual Field Tests , Visual Fields , Young AdultSubject(s)
Angiogenesis Inhibitors/administration & dosage , Nerve Fibers/pathology , Optic Disk/pathology , Retinal Ganglion Cells/pathology , Vascular Endothelial Growth Factor A/antagonists & inhibitors , Wet Macular Degeneration/drug therapy , Angiogenesis Inhibitors/adverse effects , Antibodies, Monoclonal/administration & dosage , Antibodies, Monoclonal/adverse effects , Antibodies, Monoclonal, Humanized , Aptamers, Nucleotide/administration & dosage , Aptamers, Nucleotide/adverse effects , Bevacizumab , Humans , Intravitreal Injections , Nerve Fibers/drug effects , Optic Disk/drug effects , Ranibizumab , Retinal Ganglion Cells/drug effects , Retreatment , Tomography, Optical CoherenceABSTRACT
BACKGROUND/AIM: To evaluate the effect of myopia on retinal nerve fibre layer (RNFL) thickness measurement by using spectral domain optical coherence tomography (Cirrus HD OCT) and scanning laser polarimetry with enhanced corneal compensator (GDx ECC). METHODS: One hundred and forty-nine eyes of 149 myopic subjects were recruited and subdivided into three groups according to their refractive errors: high myopia group (spherical equivalent (SE) ≤ -6 D); moderate group (-3 D ≥ SE > -6 D); low group (-0.5D ≥ SE > - 3 D). RNFL thickness was measured by Cirrus High Definition (HD) OCT and GDx ECC. Associations between RNFL thickness and axial length/SE were evaluated by using Pearson correlation analysis. RESULTS: Average RNFL thickness measured with Cirrus OCT correlated significantly with axial length (r = -0.322, p < 0.001) and SE (r = 0.291, p < 0.001). No significant correlation was detected between axial length (r = -0.068, p = 0.407)/SE (r = 0.109, p = 0.187) and RNFL thickness measured with GDx ECC. CONCLUSION: Average RNFL thickness measured with Cirrus HD OCT decreases as the degree of myopia increases while no such correlation was detected in GDx ECC. Histological studies are warranted to further our understanding of the relationship between RNFL thickness and myopia.
