Developing a DR screening model at a Physician’s clinic has become easy and economical. DR diagnosis can be achieved through image analysis or AI-based algorithms which requires basic resources such as a fundus camera, a trained technician to capture high-quality retinal images, and an internet connection.

In India, options are available to enhance your skill in fundus examination and fundus photography through certified courses on DR, e.g., courses offered by Indian Health Outcomes,Public Health and Economics Research Centre (IHOPE) [6].

Screening models for diabetic clinics where there is no facility for screening to be done by an ophthalmologistDirect ophthalmoscopy by the Physicians

Physicians and primary health care providers may use a direct ophthalmoscope (DO) for DR screening. Most of the doctors are trained in this technique during their undergraduate training [7].

Tele-screening using portable or non-portable fundus cameras

A retinal fundus camera is used to take photos of the retina through an undilated (non-mydriatic) pupil that can be used to capture retinal images at Physician clinics. Details of the different types of fundus cameras available in the market utilized for DR screening are provided in Table 2. With simple training, any clinic assistant or optometrist (if available) can capture retinal images using these fundus cameras. These images can be stored and forwarded online to remote ophthalmologists or trained graders (today very few are available) [8]. The retina specialist will review the images, grade them for DR severity and generate a report to be sent back to the Physician’s office. This whole process may take a few hours to a few days depending on the resources available (Fig. 2).

Table 2 Different types of Fundus cameras utilized for the DR screeningFig. 2

DR screening using Teleophthalmology

Tele-screening using portable or non-portable fundus cameras using AI

Artificial Intelligence (AI) is playing a major role in DR screening. AI is able to grade the retinal images equivalent to a retina specialist and can identify referable DR and not referable DR. More importantly, it can grade and generate a report almost instantaneously. The patient will be able to get his eye report within a few minutes and the Physician can advise the patient accordingly [9].

The sensitivity and specificity of a few commercial automated DR grading software are given in Table 3 [10,11,12,13].

Table 3 Sensitivity and Specificity of the commercial automated DR grading algorithms

The report is provided to the patient along with a disclaimer that it is a screening test with a specific sensitivity and specificity and cannot be used for any medicolegal purpose. The main purpose of the screening test and the automated report is to alert the patients in case any evidence of DR is found so that he or she can be timely referred for a detailed evaluation and further management by an ophthalmologist. This may ensure better compliance for DR screening and reduce the risk of vision loss due to DR.

Physician clinics with an ophthalmology referral facility can ensure timely diagnosis and management of DR.

DR screening as a part of diabetes care

Incorporation of DR screening as a standard of care for diabetes with regular referral to an ophthalmologist for DR screening.

The second option is that instead of sending every patient to the Ophthalmologist for DR screening, an in-clinic screening can be done using a fundus camera with AI or without AI using teleophthalmology.

If the patient has a referral DR, then is sent for further evaluation and management to the in-house ophthalmologist.

Community-based DR screeningDR screening during diabetes screening

Non-Governmental Organizations (NGOs), diabetic clinics and corporate offices conduct annual health check-up programs or diabetes screening programs annually [14]. DR screening can be included as a part of the package. These days, corporate screening programs are also implemented in offices where a sedentary lifestyle and work stress increase the risk of diabetes and DR at a younger age, and these camps can help in opportunistic screening for DR.

Risk-based DR screening

Risk-based screening (age, duration of diabetes, blood sugar levels, cholesterol levels, blood pressure levels) would be feasible, cost-effective, and safe, and the screening can be individualized based on the risk score.

The All India Ophthalmological Society (AIOS) task force committee and Vitreo Retinal Society India (VRSI) recommends diabetic retinopathy (DR) screening for individuals with known diabetes who are receiving treatment and have a random blood sugar (RBS) level of ≥ 200 mg/dl (≥ 11.1 mmol/l), or have glycosylated hemoglobin (HbA1C) levels of > 6.5% (48 mmol/l). Screening is also necessary for females with type-1 diabetes and gestational diabetes when they first report to a healthcare provider [15].