OCT TEST HOW TO

The fundus image is a classic example of nonproliferative diabetic retinopathy with CSME. Here is the clinical fundus image of the above patient. Like I said earlier if we get acquainted with the clinical fundus image beforehand reading the OCT scans, it becomes simple to correlate the abnormalities on OCT scans and the diagnosis of the disease also becomes a simpler task. Also, note the hyper-reflective aggregations and dots in the outer retina (sub-segment 3) representing hard exudates clinically. Here you can see gross hyporeflective cystic spaces throughout the retina (ie both inner retina and outer retinal layers sub-segments 2 & 3 are involved). Here is an OCT image of a 55-year-old patient with systemic diabetes and has been treated for diabetic retinopathy. Let's look at one more very common clinical case. (Reminder always correlates clinical history also before making a diagnosis.) This OCT image is a classic representation of Pseudophakic CME. Also, note the bump above the RPE line of the neurosensory detachment of retinal layers above RPE. Here we see multiple cystic spaces in the intraretinal architecture (Sub-Segment 3). Here is an OCT image of a 61-year-old gentleman who underwent cataract surgery 3 weeks back. This fundus picture is grossly showing pigmentary changes with yellow coloured deposits over temporal part of macula along with straitening of retinal vessels around it suggesting a possible clinical condition of macular telangiectasia type 2 (MACTEL). The rest of the OCT image including the deeper layers of the retina is appearing normal.īefore commenting on the diagnosis it is wise to retrospectively analyze the fundus photo of this eye. This OCT image shows hyporeflective cavitatory spaces in the inner retina (sub-segment number 2). In this image, you can see a hyperreflective membrane in VR interface Sub-Segment which is exerting traction to the underneath retinal layers suggesting an Epiretinal membrane (ERM).

Let’s learn to read one more similar OCT image. there are some other subtle abnormalities in this OCT image of VMT like cystic changes in the inner retina and the neurosensory detachment in deeper layers which we will discuss once we go through each of the 5 sub-segments). VR interface gives us a clue to the possible clinical diagnosis of vitreo-macular traction (VMT). Here we can easily appreciate a hyper-reflective layer in the sub-segment number 1 which is attached at fovea viz. Now let's see some examples of abnormal macular OCTs of common retinal diseases and interpret them by sub-segmenting them. Always correlate your OCT interpretation or for that matter any diagnostic imaging to your clinical examination findings. examine the patients in detail, try interpreting the clinical fundus photos before you jump in to read and interpret the OCT scans. My personal advice would be to be a good clinician first i. Henceforth in order to read and interpret a macular OCT scan rapidly, we must keep in mind the normal appearance of these 5 sub-segments.Ī thumb rule before interpreting any OCT image is to be aware of the background clinical history and fundus photo of the same eye of which you are going to interpret the OCT image. THIS IS HOW THE NORMAL MACULAR SCAN LOOKS LIKE. Let us first review the normal macular OCT. These5 OCT sub-segments can be used for quick interpretation of macular OCT scans.

And also just by looking at the diseased/damaged retinal layer, we can identify probable clinical disease. So if we segment the OCT image into 5 layer-wise sub-segments, it becomes very easy to read and interpret the retinal pathology.

OCT TEST HOW TO

How to quickly read a macular OCT?Īn OCT image gives you layer by layer information of retinal tissue. And so correct interpretation of OCT scans helps us in understanding the disease pathologically which in turn aids in prognosticating and making treatment decisions. In today’s practice, OCT is indisputably an essential diagnostic tool for every retinal surgeon. Optical Coherence Tomography (OCT) is a quick, non-invasive, reproducible, and optical analog of ultrasound imaging which is as good as in vivo viewing of individual retinal layers histologically.

Oct test