What Is Optical Coherence Tomography (OCT)?

Optical Coherence Tomography

What is Optical Coherence Tomography (OCT)?

OOP uses extremely low-energy near-infrared laser light, projected onto a designated area of the retina (including the cornea, anterior chamber, and retina) according to a computer program, and scans it. Sensors collect the light reflected from the retina, and advanced computer programs analyze the optical properties of this reflected light (low-correlation interferometry). These properties vary depending on the thickness of the retinal layers and the optic nerve, allowing for the analysis of the layered structure of the retina and optic nerve.

What are the advantages of OCT?

Posterior chamber OOP uses a non-invasive method to analyze the layered structure of the retina (the part of the eye responsible for light perception, like film in a camera), achieving a resolution of less than 10 micrometers (vertical) and 20 micrometers (horizontal), providing detail comparable to a super microscope. Anterior chamber OOP can analyze the cornea, iris, anterior chamber angle, and anterior lens.

The latest high-resolution optical coherence tomography (OCT) scanners can achieve resolutions as high as 5-7 micrometers, allowing for more detailed analysis of layered structures (retina and macula), optic nerve, and anterior chamber.

Clinical Applications: The application of OCT scanners enables ophthalmologists to understand and master the pathology of many complex diseases related to the retina and optic nerve. It aids in the diagnosis, evaluation, and monitoring of changes and progress before and after surgery for various eye diseases, including:

1. Macular Degeneration: such as full-thickness/lamellar macular perforation, detachment, tearing, high myopia macular degeneration, age-related macular degeneration, central serous chorioretinopathy, macular edema, macular wrinkling, etc.

2. Retinal Degeneration: diabetic retinopathy, diabetic macular degeneration, epiretinal membrane disease, etc.; retinal diseases caused by retinal vascular diseases. / Macular edema

3. Optical nerve layer lesions: such as damage and thinning of the optic nerve layer in glaucoma, etc.

4. Optical nerve lesions: such as optic disc cupping, optic disc fovea, optic disc drusen caused by optic nerve atrophy in glaucoma, etc.

5. Assessing the thickness of the ganglion complex in the macular region helps in the early diagnosis of glaucoma.

6. Assessing the depth and angle of the anterior chamber and monitoring changes in the anterior chamber angle (e.g., in suspected narrow-angle glaucoma patients).

7. Assessing the diameter and thickness of the cornea, corneal flaps after corneal refractive surgery (e.g., corneal refractive surgery), and other corneal lesions (e.g., keratoconus).

8. Assessing the surface of the intraocular lens after intraocular lens or cataract surgery.