Ask the Experts
Eye Scans and Diagnosis
Paragon clinic has invested in a range of high-tech diagnostic equipment to provide state-of-the-art treatment to our patients. Unlike other clinics, we include your diagnostic tests in your consultation fee. A private consultation anywhere else does not include these tests, and they are billed separately when your consultant requests them. This will make your final bill 2-3 times that you were quoted initially.
When you ring for an eye consultation, make sure you ask if any diagnostic eye tests are included in the price quoted for consultation.
The tests we include in our consultation costs are:
- OCT for macula
- OCT for glaucoma
- Corneal topography
- Visual field analysis
- Wavefront analysis
OCT Scans: A Detailed Evaluation of Your Eye Health
An Optical Coherence Tomography scan (commonly referred to as an OCT scan) is the latest advancement in imaging technology. With the OCT your eye doctor is able to evaluate the health of the optic nerve & retina conditions in order to discover the earliest signs of eye disease & keep your eyes healthy. Similar to ultrasound, this diagnostic technique employs light rather than sound waves to achieve higher resolution pictures of the structural layers of the back of the eye.
A scanning laser used to analyse the layers of the retina and optic nerve for any signs of eye disease, similar to an CT scan of the eye. It works using light without radiation, and is essential for early diagnosis of glaucoma, macular degeneration and diabetic retinal disease.
With an OCT scan, doctors are provided with color-coded, cross-sectional images of the retina. These detailed images are revolutionizing early detection and treatment of eye conditions such as wet and dry age-related macular degeneration, glaucoma, retinal detachment and diabetic retinopathy.
An OCT scan is a noninvasive, painless test. It is performed in about 10 minutes. Paragon Clinic has experienced consultant ophthalmologists and Nurse consultants trained to interpret the findings of the scan.
Wet AMD leads to intraretinal fluid accumulation– fluid between the layers of the retina, and subretinal fluid accumulation – fluid behind the retina. The choroidal neovascular membrane which is the cause of the fluid collection can be visualized on an OCT scan.
This is an OCT of a pigment epithelial detachment (PED) in wet AMD with some adjacent subretinal fluid and an overlying area of focal intraretinal fluid.
Drusen: Lumps of deposits under the Retinal Pigment Epithelium.
Geographic atrophy: Thinning of the outer retinal layers with OCT signal penetrating deeper into the choroid.
This is classic DMO with cystoid intraretinal fluid pockets in the part of the retina called the outer plexiform layer. Subretinal fluid, which is present in severe DMO, is also seen in this OCT image.
Central retinal vein occlusion (CRVO) causes severe cystoid macular oedema. There isn’t a clear differentiation between oedema from vein occlusion and diabetic macular oedema on OCT, but your consultant will corelate the OCT findings with a retinal examination to come to a
CSR has a central sub retinal fluid collection, and a thickened choroid on OCT scan.
A dense epiretinal membrane (ERM) can be seen here leading to inner retinal wrinkling and distortion of the foveal contour. A severe ERM can also be associated with cystoid macular oedema.
Full-thickness macular holes are very easy to diagnose with OCT. They are always a foveal, full-thickness defect that can have associated cystoid macular oedema. Here, there is traction from the posterior hyaloid membrane that opens the hole in a “can opener” effect.
Here, the gel of the eye, the vitreous has separated, leaving a central opening and a full thickness defect.
A retinal detachment is usually diagnosed clinically and with exam, but shallow macular detachments are sometimes hard to appreciate early on. If any doubt, a retinal OCT can demonstrate a detachment easily.
Optic nerve OCT
Optic nerve and nerve fiber layer OCT helps in the management of glaucoma. The OCT machines provide automated, serial analysis of the nerve fiber layer thickness, cup-to-disc ratio, and other measurements.
They can compare the patient’s optic nerve and nerve fiber measurements against age-matched normal patients to show areas of loss. These analyses have become an important adjunct to visual field testing in the treatment of glaucoma. It can also be used to track optic nerve oedema.
Comprehensive longitudinal assessment of optic nerve photographs, Retinal Nerve fibre Layer and ganglion cell thickness data in a change-over-time bilateral report.
Wavefront aberrometry is an objective method of measuring refractive power, using a tool to measure the manner in which a light beam moves through the tested eye. It offers detailed measurements of the movement of the light wavefront.
In this way it can be used in the diagnosis of both higher-order and lower-order refractive errors. Higher-order errors refer to conditions that include complex visual defects, unlike lower-order errors such as nearsightedness, farsightedness and astigmatism.
In addition, the technique is useful as a guide in making of spectacles and contact lenses to offer sharper and clearer vision. Formerly, higher-order aberrations such as spherical aberration were ignored, both in surgical and lens correction. However, being able to detect and evaluate them has allowed better vision correction and even fewer post-surgical artefacts.
The method used to identify vision errors is based on wavefront measurements, calculated using Zernike polynomials. This produces a topographic image of the distorted wavefront. This is used to design very accurate correction lenses or to guide refractive surgery.
As part of Paragon Clinic’s high tech approach to cataract and refractive surgery, we use data from wavefront analysis (in addition to many other tests) to select the best lens options and refractive surgery solutions for our patients.