OCT of the eye or optical coherence tomography is a noninvasive investigation used by Eye doctor in Islamabad to take images of the retina. It allows healthcare experts to look at the distinctive layers of the retina and treat the underlying disease accordingly. Read on to know more about OCT and its numerous uses:

What is optical coherence tomography?

Optical coherence tomography (OCT) is a tool that gives us an in vivo cross-section of the retina. OCT has been in use since its introduction in the early 1990s to make a map of the retina using a concept known as inferometry. OCT gives us retinal images that have an accuracy within 10 to 15 microns. With OCT, the distinctive layers of the retina can be measured and mapped and it is these measurements that help us make diagnosis.

OCT works just like ultrasonography; however, instead of sound waves, OCT uses light waves. OCT measures the thickness of the retina by throwing red light onto the retinal layers. Thereafter, this reflection of the dim red light from the retinal layers is used to create the images. A detailed view of the retina is, therefore, produced at near-cellular resolution in real-time.

OCT is used not only in ophthalmology, but is also used by healthcare providers in heart and vascular medicine to make images of the blood vessels during the procedure of cardiac catheterization. Other fields that also use OCT include: dermatology, pulmonology, oncology, dentistry and gastroenterology.

Apart from traditional OCT, optical coherence tomography angiography can also be used to view the blood vessels of the retina. Unlike conventional angiography, angiography with OCT does not need injection of dye into the blood vessels for viewing.

What are the uses of OCTs?

Uses of OCT include:

• Diagnosis of certain conditions like glaucoma and retinopathies.
• Monitoring of disease of the anterior chamber like uveitis.
• To verify the results of the visual acuity.
• Verifying retinal swelling.
• To check if the given medication is working for the patient.
• Evaluating the condition of the optic nerve head (ONH) to observe any changes.
• Assessing the corneal graft after corneal transplant surgery.

What are the indications of OCT?

OCT is performed for suspected eye conditions such as:

• Glaucoma: in this disease, the intraocular pressure rises due to increased production or poor drainage of the aqueous humor. If there is excessive buildup of this fluid in the eye, it can damage the optic nerve. The condition of this optic nerve head (ONH) can be assessed through OCT imaging.
• Diabetic retinopathy: in diabetic retinopathy, the persistently raised blood sugar levels cause damage to the retinal blood vessels that can swell and leak. This leakage can make the retinal layers edematous, assessed through the OCT.
• Age-related macular degeneration (ARMD): in ARMD, there is progressive thinning of the retina, along with visual changes. OCT helps to assess the retinal thickness.
• Cone and cone-rod dystrophies: rods and cones are cells of the retina that perceive light and color. Diseases of the rods and cones can result in visual loss.
• Macular pucker: or epiretinal membrane is when there are creases, bulges or wrinkles on the retina. Patient often complains of wavy vision or blank areas in the central vision. The retina can be assessed in this situation through OCT
• Tumors of the chorio-retinal layer: these are the cancers occurring in the retinal and choroidal layer.
• Macular hole: if the retina pulls apart, a hole can be formed on the macula. This hole can be seen on the OCT.
• Cystoid macular edema: CME causes swelling of the macula due to fluid leakage from the vessels. These swellings can be seen on the OCT.

What are the benefits of getting OCT done?

The benefits of getting an OCT from Best Eye Specialist in Rawalpindi include:

• Non-invasive
• Painless
• Helps in early diagnosis of eye conditions
• Helps to assess progression of disease
• Helps to diagnose diseases in children which is otherwise difficult