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2.  Ultrahigh resolution optical coherence tomography of birdshot retinochoroidopathy 
The British Journal of Ophthalmology  2005;89(12):1660-1661.
doi:10.1136/bjo.2005.076570
PMCID: PMC1772985  PMID: 16299151
birdshot retinochoroidopathy; optical coherence tomography
3.  Ultrahigh resolution optical coherence tomography in non-exudative age related macular degeneration 
Aim
To describe the appearance of the non-exudative forms of age related macular degeneration (AMD) as imaged by ultrahigh resolution optical coherence tomography (UHR-OCT).
Methods
A UHR-OCT ophthalmic imaging system, which utilises a femtosecond laser light source capable of ~3 μm axial resolution, was employed to obtain retinal cross sectional images of patients with non-exudative AMD. Observational studies of the resulting retinal images were performed.
Results
52 eyes of 42 patients with the clinical diagnosis of non-exudative AMD were imaged using the UHR-OCT system. 47 of the 52 (90%) eyes had the clinical diagnosis of drusen and/or retinal pigment epithelial (RPE) changes. In these patients, three patterns of drusen were apparent on UHR-OCT: (1) distinct RPE excrescences, (2) a saw toothed pattern of the RPE, and (3) nodular drusen. On UHR-OCT, three eyes (6%) with a clinical diagnosis of non-exudative AMD had evidence of fluid under the retina or RPE. Two of these three patients had findings suspicious for subclinical choroidal neovascularisation on UHR-OCT.
Conclusion
With the increased resolution of UHR-OCT compared to standard OCT, the involvement of the outer retinal layers are more clearly defined. UHR-OCT may allow for the detection of early exudative changes not visible clinically or by angiography.
doi:10.1136/bjo.2005.076612
PMCID: PMC1860181  PMID: 16424532
4.  Retinal nerve fibre layer thickness measurement reproducibility improved with spectral domain optical coherence tomography 
The British journal of ophthalmology  2009;93(8):1057-1063.
Background/aims
To investigate retinal nerve fibre layer (RNFL) thickness measurement reproducibility using conventional time-domain optical coherence tomography (TD-OCT) and spectral-domain OCT (SD-OCT), and to evaluate two methods defining the optic nerve head (ONH) centring: Centred Each Time (CET) vs Centred Once (CO), in terms of RNFL thickness measurement variability on SD-OCT.
Methods
Twenty-seven eyes (14 healthy subjects) had three circumpapillary scans with TD-OCT and three raster scans (three-dimensional or 3D image data) around ONH with SD-OCT. SD-OCT images were analysed in two ways: (1) CET: ONH centre was defined on each image separately and (2) CO: ONH centre was defined on one image and exported to other images after scan registration. After defining the ONH centre, a 3.4 mm diameter virtual circular OCT was resampled on SD-OCT images to mimic the conventional circumpapillary RNFL thickness measurements taken with TD-OCT.
Results
CET and CO showed statistically significantly better reproducibility than TD-OCT except for 11:00 with CET. CET and CO methods showed similar reproducibility.
Conclusions
SD-OCT 3D cube data generally showed better RNFL measurement reproducibility than TD-OCT. The choice of ONH centring methods did not affect RNFL measurement reproducibility.
doi:10.1136/bjo.2009.157875
PMCID: PMC2861342  PMID: 19429591
5.  Projection OCT fundus imaging for visualising outer retinal pathology in non-exudative age-related macular degeneration 
Aims
To demonstrate ultrahigh-resolution, three-dimensional optical coherence tomography (3D-OCT) and projection OCT fundus imaging for enhanced visualisation of outer retinal pathology in non-exudative age-related macular degeneration (AMD).
Methods
A high-speed, 3.5 μm resolution OCT prototype instrument was developed for the ophthalmic clinic. Eighty-three patients with non-exudative AMD were imaged. Projection OCT fundus images were generated from 3D-OCT data by selectively summing different retinal depth levels. Results were compared with standard ophthalmic examination, including fundus photography and fluorescein angiography, when indicated.
Results
Projection OCT fundus imaging enhanced the visualisation of outer retinal pathology in non-exudative AMD. Different types of drusen exhibited distinct features in projection OCT images. Photoreceptor disruption was indicated by loss of the photoreceptor inner/outer segment (IS/OS) boundary and external limiting membrane (ELM). RPE atrophy can be assessed using choroid-level projection OCT images.
Conclusions
Projection OCT fundus imaging facilities rapid interpretation of large 3D-OCT data sets. Projection OCT enhances contrast and visualises outer retinal pathology not visible with standard fundus imaging or OCT fundus imaging. Projection OCT fundus images enable registration with standard ophthalmic diagnostics and cross-sectional OCT images. Outer retinal alterations can be assessed and drusen morphology, photoreceptor impairment and pigmentary abnormalities identified.
doi:10.1136/bjo.2007.136101
PMCID: PMC2743133  PMID: 18662918
6.  Ultrahigh resolution optical coherence tomography in non‐exudative age related macular degeneration 
Aim
To describe the appearance of the non‐exudative forms of age related macular degeneration (AMD) as imaged by ultrahigh resolution optical coherence tomography (UHR‐OCT).
Methods
A UHR‐OCT ophthalmic imaging system, which utilises a femtosecond laser light source capable of ∼3 μm axial resolution, was employed to obtain retinal cross sectional images of patients with non‐exudative AMD. Observational studies of the resulting retinal images were performed.
Results
52 eyes of 42 patients with the clinical diagnosis of non‐exudative AMD were imaged using the UHR‐OCT system. 47 of the 52 (90%) eyes had the clinical diagnosis of drusen and/or retinal pigment epithelial (RPE) changes. In these patients, three patterns of drusen were apparent on UHR‐OCT: (1) distinct RPE excrescences, (2) a saw toothed pattern of the RPE, and (3) nodular drusen. On UHR‐OCT, three eyes (6%) with a clinical diagnosis of non‐exudative AMD had evidence of fluid under the retina or RPE. Two of these three patients had findings suspicious for subclinical choroidal neovascularisation on UHR‐OCT.
Conclusion
With the increased resolution of UHR‐OCT compared to standard OCT, the involvement of the outer retinal layers are more clearly defined. UHR‐OCT may allow for the detection of early exudative changes not visible clinically or by angiography.
doi:10.1136/bjo.2005.076612
PMCID: PMC1860181  PMID: 16424532
ultra high resolution optical coherence tomography; age related macular degeneration; drusen

Results 1-6 (6)