Investigation of Light Parameters on Image Quality and Optical Coherence Tomography

In this work, image quality and optical coherence tomography were studied. The results of the study show that there is a very significant difference between ultrasound and optical coherence tomography to produce an image with a different wave. To understand this, we studied the basic principle of optical coherence tomography in the Michelson interferometer using monochromatic and broadband sources. Time-domain and spectral-domain measurements, which exist at the detector level, are briefly described using a glass sample. The time-domain signal strength of the Michelson interferometer using a broadband source is a Gaussian envelope.

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Swept Source Optical Coherence Tomography Angiography for Contact Lens-Related Corneal Vascularization

Journal of Ophthalmology ◽

10.1155/2016/9685297 ◽

2016 ◽

Vol 2016 ◽

pp. 1-3 ◽

Cited By ~ 18

Author(s):

Marcus Ang ◽

Yijun Cai ◽

Anna C. S. Tan

Keyword(s):

Optical Coherence Tomography ◽

Image Quality ◽

Contact Lens ◽

Optical Coherence Tomography Angiography ◽

Quality Score ◽

Image Quality Score ◽

Optical Coherence ◽

Swept Source ◽

Corneal Vascularization ◽

Significant Difference

Purpose. To describe a novel technique of adapting a swept-source optical coherence tomography angiography (OCTA) to image corneal vascularization.Methods. In this pilot cross-sectional study, we obtained 3 × 3 mm scans, where 100,000 A-scans are acquired per second with optical axial resolution of 8 μm and lateral resolution of 20 μm. This was performed with manual “XYZ” focus without the anterior segment lens, until the focus of the corneoscleral surface was clearly seen and the vessels of interest were in focus on the corresponding red-free image. En face scans were evaluated based on image quality score and repeatability.Results. We analyzed scans from 10 eyes (10 patients) with corneal vascularization secondary to contact lens use in 4 quadrants, with substantial repeatability of scans in all quadrants (mean image quality score 2.7 ± 0.7;κ=0.75). There was no significant difference in image quality scores comparing quadrants (superior temporal: 2.9 ± 0.6, superior nasal: 2.8 ± 0.4, inferior temporal: 2.5 ± 0.9, and inferior nasal: 2.4 ± 1.0;P=0.276) and able to differentiate deep and superficial corneal vascularization.Conclusion. This early clinical study suggests that the swept-source OCTA used may be useful for examining corneal vascularization, which may have potential for clinical applications such as detecting early limbal stem cell damage.

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Reproducibility of Angle Metrics Using the Time-Domain Anterior Segment Optical Coherence Tomography: Intra-Observer and Inter-Observer Variability

Current Eye Research ◽

10.3109/02713683.2014.930155 ◽

2014 ◽

Vol 40 (5) ◽

pp. 496-500 ◽

Cited By ~ 10

Author(s):

Jyotsna Maram ◽

Xiaojing Pan ◽

Srinivas Sadda ◽

Brian Francis ◽

Kenneth Marion ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Time Domain ◽

Anterior Segment ◽

Observer Variability ◽

Optical Coherence ◽

Inter Observer Variability ◽

The Time Domain

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Enhanced-Resolution Optical Coherence Tomography Imaging

Ophthalmologica ◽

10.1159/000443971 ◽

2016 ◽

Vol 235 (3) ◽

pp. 163-172 ◽

Cited By ~ 2

Author(s):

Akihito Uji ◽

Tomoaki Murakami ◽

Shigeta Arichika ◽

Yuki Muraoka ◽

Shin Yoshitake ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Image Quality ◽

Super Resolution ◽

Processing Technique ◽

Image Processing Technique ◽

Optical Coherence ◽

Enhanced Resolution ◽

Opinion Score ◽

Significant Difference ◽

Bicubic Interpolation

Purpose: The effect of the enhanced-resolution imaging (ERI) technique on optical coherence tomography (OCT) images was evaluated. Methods: A total of 5 healthy subjects and 20 patients diagnosed with various eye diseases were recruited into the study. ERI, a novel image processing technique, was accomplished by using super-resolution technology, and was assessed by objectively and subjectively comparing the image quality among three different image groups: images enlarged without bicubic interpolation (NONE), with bicubic interpolation (IP), and with ERI. Results: ERI showed a higher ratio of the detailed variance to the background variance than NONE, whereas no significant difference was detected between NONE and IP. The mean opinion score of 5 experienced retinal specialists for ERI was significantly higher than that for IP. Conclusions: ERI generated a sharper image and clearly visualized small objects. Additionally, it is effective in enhancing OCT image quality.

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Influence of cataract on image quality and macular thickness measured using spectral domain optical coherence tomography: a prospective cohort study

International Journal of Advances in Medicine ◽

10.18203/2349-3933.ijam20171058 ◽

2017 ◽

Vol 4 (2) ◽

pp. 546 ◽

Cited By ~ 1

Author(s):

Vasu Kamaladevi Lathika ◽

Susan Prakash Minu ◽

K. Skariah Charles

Keyword(s):

Optical Coherence Tomography ◽

Image Quality ◽

Imaging Techniques ◽

Signal Strength ◽

Macular Thickness ◽

Spectral Domain ◽

Central Macular Thickness ◽

Optical Coherence ◽

Clinically Significant ◽

Oct Image

Background: Optical coherence tomography (OCT) is one of the most useful imaging techniques in the management of retinal diseases affecting the macula. Factors affecting the image quality of OCT may affect the macular thickness and hence treatment of retinal pathologies. This study was aimed to evaluate the influence of cataract on macular scans using spectral domain OCT.Methods: The prospective study was done in 36 patients with cataract. Cataract was graded as cortical, nuclear or posterior cataracts. All patients underwent small incision cataract surgery. Pre and post-operative imaging of the macula (4 weeks after surgery) using spectral domain OCT. The signal strength and central macular thickness (CMT) measurements were made before and after the surgery and analysed statistically.Results: The majority (66.7%) of patients had posterior cataracts. A statistically significant improvement in OCT image quality (as assessed by signal strength) was noted post operatively. This was maximum for posterior cataracts (2.9), followed by cortical cataract (1.6), while nuclear cataracts had the least increase in signal strength (1.3). The difference in signal strength gain between posterior and nuclear cataracts was found to be statistically significant (p = 0.05). The increase in CMT was clinically significant only in 8.2% of the study population. No patient with nuclear cataract had a clinically significant increase in CMT following surgery.Conclusions: Cataract can influence OCT image quality as well as central macular thickness measurements. Both were found to be affected maximally by posterior cataracts, followed by cortical, while nuclear cataracts had the least influence.

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