Ophthalmology

In this test, a low energy pinpoint near-infrared laser beam is projected and scanned across designated structures of the eyeball, including the cornea, anterior segment and the back of the eye (retina) in a pre-defined pattern. Sensors will then detect the reflected light, after which the advanced computerised algorithm will analyse the reflected light (low-coherence interferometry), which has been changed in accordance with structural layers of the retina and its nerve fibre layer.

Clinical Applications 
Since its inception, OCT has helped ophthalmologists tremendously in understanding the pathology of many complicated retinal and optic nerve diseases. It can facilitate diagnosis, assessment and progress monitoring of many eye problems before and after treatment, including 

1. Macula diseases: e.g. full thickness/lamellar macular hole, macular detachment, macular schisis, high myopic macular pathology, age-related macular degeneration, central serous chorioretinopathy, macular oedema, macular pucker etc.
2. Retinal problems: e.g. diabetic retinopathy and maculopathy, epiretinal membrane etc. Retinal/macular oedema secondary to retinovascular disease.
3. Retinal nerve fibre layer pathology, e.g. glaucomatous retinal nerve fibre damage and thinning.
4. Optic nerve pathology, e.g. disc cupping in glaucomatous optic neuropathy, optic disc pit, disc drusens, etc.
5. Assessment of ganglion cell complex thickness at the macula, which can help diagnose glaucoma early.
6. Assessment of scanning the anterior segment and measurement of parameters.
7. Assessment of cornea diameter, cornea thickness, the cornea flap after corneal-refractive surgery (e.g. LASIK) and many other corneal pathologies (e.g. keratoconus). 
    

Overall, the development of OCT has greatly enhanced the quality of care and management of many eye patients in a fast, non-invasive and reproducible way.