Diabetic Retinopathy Part 2
Diagnosis
Diabetic retinopathy is detected during an eye examination that includes:
Visual acuity test: This test uses an eye chart to measure how well a person sees at various distances (i.e., visual acuity).
Pupil dilation: The eye care professional places drops into the eye to dilate the pupil. This allows him or her to see more of the retina and look for signs of diabetic retinopathy. After the examination, close-up vision may remain blurred for several hours.
Ophthalmoscopy or fundus photography:
Ophthalmoscopy is an examination of the retina in which the eye care professional:
(1) looks through a slit lamp biomicroscope with a special magnifying lens that provides a narrow view of the retina, or
(2) wearing a headset (indirect ophthalmoscope) with a bright light, looks through a special magnifying glass and gains a wide view of the retina. Hand-held ophthalmoscopy is insufficient to rule out significant and treatable diabetic retinopathy. Fundus photography generally recreate considerably larger areas of the fundus, and has the advantage of photo documentation for future reference, as well as availing the image to be examined by a specialist at another location and/or time.
Fundus Fluorescein angiography (FFA):
This is an imaging technique which relies on the circulation of Fluorescein dye to show staining, leakage, or non-perfusion of the retinal and choroidal vasculature.
Optical coherence tomography (OCT):
This is an optical imaging modality based upon interference, and analogous to ultrasound. It produces cross-sectional images of the retina (B-scans) which can be used to measure the thickness of the retina and to resolve its major layers, allowing the observation of swelling.
Digital Retinal Screening Programs:
Systematic programs for the early detection of eye disease including diabetic retinopathy are becoming more common, such as in the UK, where all people with diabetes are offered retinal screening at least annually. This involves digital image capture and transmission of the images to a digital reading center for evaluation and treatment referral.
Computer Vision Approach:
It is a System developed by Researchers at IIT Kharagpur in collaboration with IBM India. It uses data analytics capabilities to automatically compare and analyse retina images of the patient. It can tell if the patient has DR and also provides risk categorisation ranging from low to medium and high.
Slit Lamp Biomicroscopy Retinal Screening Programs: Systematic programs for the early detection of diabetic retinopathy using slit-lamp biomicroscopy. These exist either as a stand alone scheme or as part of the Digital program, where the digital photograph was considered to lack enough clarity for detection and/or diagnosis of any retinal abnormality.
The eye care professional will look at the retina for early signs of the disease, such as:
leaking blood vessels,
retinal swelling, such as macular edema, pale, fatty deposits on the retina (exudates) – signs of leaking blood vessels, damaged nerve tissue (neuropathy), and any changes in the blood vessels.
If macular edema is suspected, FFA and sometimes OCT may be performed.
According to a DRSS user manual, poor quality images (which may apply to other methods) may be caused by cataract, poor dilation, ptosis, external ocular condition, or learning difficulties. There may be artefacts caused by dust, dirt, condensation, or smudge.
To be Continued.....
Diagnosis
Diabetic retinopathy is detected during an eye examination that includes:
Visual acuity test: This test uses an eye chart to measure how well a person sees at various distances (i.e., visual acuity).
Pupil dilation: The eye care professional places drops into the eye to dilate the pupil. This allows him or her to see more of the retina and look for signs of diabetic retinopathy. After the examination, close-up vision may remain blurred for several hours.
Ophthalmoscopy or fundus photography:
Ophthalmoscopy is an examination of the retina in which the eye care professional:
(1) looks through a slit lamp biomicroscope with a special magnifying lens that provides a narrow view of the retina, or
(2) wearing a headset (indirect ophthalmoscope) with a bright light, looks through a special magnifying glass and gains a wide view of the retina. Hand-held ophthalmoscopy is insufficient to rule out significant and treatable diabetic retinopathy. Fundus photography generally recreate considerably larger areas of the fundus, and has the advantage of photo documentation for future reference, as well as availing the image to be examined by a specialist at another location and/or time.
Fundus Fluorescein angiography (FFA):
This is an imaging technique which relies on the circulation of Fluorescein dye to show staining, leakage, or non-perfusion of the retinal and choroidal vasculature.
Optical coherence tomography (OCT):
This is an optical imaging modality based upon interference, and analogous to ultrasound. It produces cross-sectional images of the retina (B-scans) which can be used to measure the thickness of the retina and to resolve its major layers, allowing the observation of swelling.
Digital Retinal Screening Programs:
Systematic programs for the early detection of eye disease including diabetic retinopathy are becoming more common, such as in the UK, where all people with diabetes are offered retinal screening at least annually. This involves digital image capture and transmission of the images to a digital reading center for evaluation and treatment referral.
Computer Vision Approach:
It is a System developed by Researchers at IIT Kharagpur in collaboration with IBM India. It uses data analytics capabilities to automatically compare and analyse retina images of the patient. It can tell if the patient has DR and also provides risk categorisation ranging from low to medium and high.
Slit Lamp Biomicroscopy Retinal Screening Programs: Systematic programs for the early detection of diabetic retinopathy using slit-lamp biomicroscopy. These exist either as a stand alone scheme or as part of the Digital program, where the digital photograph was considered to lack enough clarity for detection and/or diagnosis of any retinal abnormality.
The eye care professional will look at the retina for early signs of the disease, such as:
leaking blood vessels,
retinal swelling, such as macular edema, pale, fatty deposits on the retina (exudates) – signs of leaking blood vessels, damaged nerve tissue (neuropathy), and any changes in the blood vessels.
If macular edema is suspected, FFA and sometimes OCT may be performed.
According to a DRSS user manual, poor quality images (which may apply to other methods) may be caused by cataract, poor dilation, ptosis, external ocular condition, or learning difficulties. There may be artefacts caused by dust, dirt, condensation, or smudge.
To be Continued.....
