How the retina can change diabetes management

How the retina can change diabetes management

Diabetes remains one of the world’s fastest-growing chronic diseases and a major public health challenge. In Brazil 12.9% of the population lives with the condition, while in the U.S., the CDC reports over 38 million affected individuals. Left unmanaged, diabetes impairs multiple organ systems.

Among its most concerning complications is diabetic retinopathy (DR), a leading cause of preventable vision loss in adults caused by microvascular alterations in the retina. The primary clinical challenge is that DR often progresses silently, remaining completely asymptomatic during its initial stages. 

In this context, fundus photography has solidified its role as a vital tool for screening, early diagnosis, and ongoing ocular monitoring. By providing detailed visualization of the retina, this imaging helps identify structural changes long before vision is compromised. 

For endocrinologist and ophthalmologist Dr. Flávia Godinho, monitoring eye health must be integrated into routine diabetic care. “The incorporation of retinal imaging into clinical practice has the potential to change management protocols, increase treatment adherence, and directly impact the prognosis and quality of life for these patients,” she emphasizes. 

Phelcom commercial analyst Daniele Oliveira, ophthalmologist and endocrinologist Dr. Flávia Godinho, and Phelcom after-sales analyst Maiara Guiliano at the Diabetes 360º event, held May 29–31 in São Paulo, SP.

Beyond blood glucose

One of the lesser-known nuances of diabetes management is that lowering blood glucose as quickly as possible is not always the safest strategy. In patients with pre-existing diabetic retinopathy, a rapid drop in blood sugar levels can trigger “early worsening,” a phenomenon that temporarily exacerbates retinal lesions and increases the risk of severe vision loss.

Dr. Godinho explains that retinal imaging is a fundamental tool for guiding medical management in these scenarios. “We must first understand the status of the retina to determine the appropriate speed and safety of glycemic control,” she states.

She recalls a case that perfectly illustrates this clinical reality: “I once had a patient come into the office saying, ‘Doctor, when my glucose was 400, I could see everything. Now that it is 110 I am practically blind. What happened?’ What had changed was simply the initiation of her diabetes treatment.”

According to Dr. Godinho, safely lowering glucose can sometimes take up to a year. “We do this gradually, monitoring retinal exams and co-managing with the ophthalmologist. If we notice any signs of progression or worsening, we slow the process down and reevaluate the strategy.”

In this dynamic, fundus photography helps endocrinologists balance two equally critical goals: controlling systemic disease and preserving patient vision. 

Diabetes and weight-loss injectables

The relationship between diabetes and weight-loss injectables (GLP-1 receptor agonists) has gained widespread attention with the popularization of medications like semaglutide, tirzepatide, and liraglutide.  While these drugs deliver significant benefits for glycemic control and weight loss, Dr. Godinho warns that close medical supervision is essential. 

“There is no scientific evidence that these drugs directly cause visual alterations or lead to blindness. The problem arises when a diabetic patient experiences a very rapid reduction in glucose levels and already has established retinopathy,” she explains. 

This precaution extends beyond injectables to any intervention capable of triggering a steep glucose drop– including insulin initiation or intensification, certain oral antidiabetic medications, highly restrictive diets, or prolonged fasting. “In some cases, the ophthalmologist faces a tremendous struggle to control the progression of diabetic retinopathy once this rapid-reduction process is triggered,” Dr. Godinho notes. 

Evaluating the retina before and during treatment can change everything. “Retinal imaging is a simple, non-invasive exam that can completely change how we manage a patient’s treatment,” she points out.  

The consequences of vision loss extend far beyond ocular health. “We are talking about independence, quality of life, the ability to work, and performing simple daily activities. When we identify the risk early, we have the opportunity to protect their vision and alter their prognosis for the rest of their life.” 

A window to systemic health

Endocrinologista Flávia Godinho em palestra no evento Diabetes 360, que ocorreu de 29 a 31 de maio, em São Paulo

During her lecture at the Diabetes 360º event, Dr. Godinho also discussed the broader role of retinal imaging in the endocrinologist’s clinical practice.

Beyond identifying diabetic retinopathy, Dr. Godinho emphasizes that fundus photography offers invaluable insights into overall vascular health, helping detect early signs of systemic diseases before symptoms surface. “Many of these systemic changes appear first in the small vessels. The retina is the only place in the body where we can directly visualize blood vessels and capillaries non-invasively. This allows us to observe microvascular changes related to hypertension, atherosclerosis, inflammation, and other conditions.”

This aspect still receives too little attention in primary and endocrine care. “We frequently evaluate sleep, diet, physical activity, and many other health metrics, but the eyes are often left in the background. However, they can provide critical information about the patient’s overall state of health.”

Because endocrinologists manage populations highly susceptible to age-related conditions, baseline retinal exams can also aid in the early identification of glaucoma and age-related macular degeneration (AMD).

Flávia também lembra que o endocrinologista acompanha uma população frequentemente exposta a doenças associadas ao envelhecimento. Nesses casos, a observação da retina pode auxiliar na identificação precoce de condições como glaucoma, degeneração macular relacionada à idade (DMRI) e outras doenças oculares potencialmente graves.

“By incorporating retinal evaluations into routine monitoring, we can identify problems sooner and refer the patient for appropriate treatment before irreversible vision loss occurs. The eye has a lot to offer to endocrinology,” she believes.

A new tool for the endocrinologist

Dr. Godinho observes that fundus photography remains underexplored outside of ophthalmology, largely because non-eyecare specialists often receive limited training in direct ophthalmoscopy during medical school.

Technologies like the Eyer2 portable fundus camera make integrating this level of care into general or endocrine practices seamless. “The Eyer makes this exam highly accessible for the endocrinologist. Image capture is simple, fast, and can be performed by trained allied health staff. In moments, the doctor has access to the images and can discuss the findings with the patient during the actual consultation,” she highlights.

The Eyer2 captures high-definition images of the ocular surface and posterior segment in just minutes without requiring pupil dilation (mydriasis). Integrated with EyerCloud—an online exam management platform—it enables practitioners to securely store, access, and track images over time. Additionally, EyerMaps artificial intelligence assists in identifying potential retinal abnormalities as a decision-support tool. (Note: EyerMaps is currently available only in the Brazilian market.)

Visualizing these images also strengthens the doctor-patient relationship. “When we show them the image and compare it to a healthy retina, they understand what is happening. This sparks greater engagement with their systemic treatment and compliance with their ophthalmological follow-ups.”

Retinal image displaying diabetic retinopathy captured by the Eyer portable fundus camera.

Retinal image displaying diabetic retinopathy captured by the Eyer portable fundus camera.

Retinal image captured with the Eyer portable fundus camera. The EyerMaps AI highlights regions with potential abnormalities associated with diabetic retinopathy. (EyerMaps is currently available only in the Brazilian market)

Public health implications

Integrating imaging technologies into primary care and chronic disease management represents a major step forward, particularly given the access barriers to specialized ophthalmological care within public health systems.

According to Dr. Godinho, one of Eyer’s primary advantages is enabling rapid, accessible triage directly at the point of care for patients managing diabetes, hypertension, and other chronic conditions. “Often, a patient waits months, or even over a year, to get a consultation with an ophthalmologist. Meanwhile, the disease continues to progress. Having access to retinal imaging at the point of primary care helps identify exactly who needs a priority referral,” she asserts.

This need is especially critical when managing advanced diabetes, where determining the ideal speed of glycemic control relies heavily on prior retinal evaluation. “The Eyer is a tool that can contribute immensely to the prevention of blindness and to more efficient public health management,” she concludes.

Premature Retinopathy: Early Diagnosis is Crucial to Prevent Childhood Blindness

Premature Retinopathy: Early Diagnosis is Crucial to Prevent Childhood Blindness

Premature Retinopathy (ROP) is an ocular condition that affects premature infants. According to retina disease and premature retinopathy specialist Samuel Montenegro, ROP is one of the primary causes of preventable childhood blindness. In Brazil, an estimated 13,500 cases occur annually, and among these cases, 1,000 infants may need treatment.

Therefore, identifying newborns in need of treatment early is crucial to reduce ROP-related blindness. Premature babies weighing up to 1.5 kilograms and/or born before 32 weeks’ gestation are a high risk group for ROP.

This period might extend to 35 weeks if the child experiences sepsis, intraventricular hemorrhage, respiratory distress syndrome, requires blood transfusions, or if the mother had a multiple pregnancy, even if the baby’s weight is above 1.5 kilograms.

This is because premature birth can disrupt the development of the baby’s retinal blood vessels. In these cases, vascularization might expand, twist, or even rupture. In advanced stages, this can lead to the formation of retinal scars or even retinal detachment, resulting in permanent vision loss.

The International Classification of ROP (ICROP) defines the disease by severity (stages 1-5), location (zones I-III), and extension in analog hours (1-12 h), with or without additional disease (arteriolar dilation and venous tortuosity), and the presence of which would indicate disease activity (4-5).

Check the table below:

Premature Retinopathy Classification
Stage 1 White line separating vascular from avascular retina
Stage 2 Elevated ridge 
Stage 3 Fibrovascular proliferation from ridge 
Stage 4 Proliferation leading to subtotal retinal detachment (4a, extrafoveal; 4b, total detachment, including fovea) 
Stage 5 Total retinal detachment (open or closed funnel)
Threshold disease (defined by CRYO-ROP) (untreated cases show poor anatomical outcomes in 50% of cases) Stage 3 retinopathy, zone I or II, with at least five contiguous hours or eight cumulative hours of extension, with an additional disease disease (arteriolar dilation and venodilation). 
Type 1 pre-threshold disease (defined by ET-ROP)Any ROP in zone I with an additional disease (aggressive posterior disease) Stage 3, zone I, without plus disease Stage 2 or 3 in zone II, with additional disease(s).
Type 2 pre-threshold disease (defined by ET-ROP)Stage 1 or 2, zone I, without additional  disease(s) Stage 3, zone 2, without additional disease(s). 

Source: Proposed Brazilian guidelines for examination and treatment of retinopathy of prematurity (ROP).

Premature Retinopathy Assessment

Image caption: Samuel Montenegro examining a newborn with the Eyer. Photo: personal archive.

ROP bears two dangerous characteristics: it’s silent, showing no visible symptoms, and it progresses rapidly. Therefore, adhering to international and national protocols for early diagnosis and treatment is crucial.

Montenegro explains that routine eye examinations for premature babies should be conducted four weeks after birth. “The child isn’t born with the disease, so it’s essential to assess during this period.”

The examination should be performed by an ophthalmologist experienced in evaluating preemies and knowledgeable about the disease to identify location and sequential retinal changes.

Image caption: Image taken with the Eyer. Photo: Samuel Montenegro.

Subsequent examination scheduling will be determined by findings from the initial examination.

After identifying ROP, Montenegro tracks and documents patients using a portable retinal camera, Eyer. This equipment, highly recommended for infant and child examinations due to its portability and high image quality, attaches to a smartphone and conducts retinal exams within minutes. It also makes images available on the online platform, EyerCloud, facilitating study and case progression monitoring for physicians.

Image caption: Image taken with the Eyer. Photo: Samuel Montenegro.

“The device has been a game-changer as it greatly assists me in capturing the patient’s retina at that exact moment, in a practical, quick, and high-quality manner,” he states. Previously, the specialist used a retina mapping lens with smartphone assistance for videos. “Then I’d freeze the image, take a screenshot, and store it on the computer. It was quite labor-intensive,” he recalls.

Premature Retinopathy Treatment

Montenegro explains that treatment is most effective when ROP is identified early. “The secret to managing this disease lies in early diagnosis and immediate treatment when necessary.”

Currently, retinal ablation with a laser is the gold-standard treatment. Depending on the stage, there are alternatives, such as anti-VEGF injections and cryotherapy. “In this disease, we’re fighting blindness. Therefore, we apply laser therapy to prevent blindness in cases where it’s the best indication. However, this may permanently restrict the field of vision,” he points out.

Children with ROP receive follow-up care from a multidisciplinary team: pediatric ophthalmologist, retina specialist, occupational therapist, and physiotherapist. This follow-up extends beyond retinal ablation, aiming to achieve early visual stimulation.

“Newborns diagnosed with ROP are at a higher risk of developing ophthalmological issues in the future, such as strabismus, amblyopia, and refractive errors. Therefore, ophthalmological follow-up after discharge is recommended,” he emphasizes.

Image caption: Samuel Montenegro examining a newborn with the Eyer. Photo: personal archive.

ROP Brazil

Montenegro is part of a project called ROP Brazil, which aims to share knowledge and further study premature retinopathy.

Various surveys indicate that the proportion of blindness caused by ROP is greatly influenced by the level of neonatal care (availability of human resources, equipment, access, and quality of care), as well as the presence of effective screening and treatment programs. Consequently, there’s significant variability in disease occurrence between developed and developing countries.

“That’s why, understanding more about the disease is essential to decrease cases of preventable childhood blindness in the country,” he states.

Glasses and coronavirus: study indicates a reduction of the risk of contamination by up to three times

Glasses and coronavirus: study indicates a reduction of the risk of contamination by up to three times

Since last year, scientists raised the hypothesis that glasses help to bar the contamination by the new coronavirus (SARS-CoV-2) through the eyes. This is because this region is also an open door for the virus, as well as a source of contagion.

Now, a recent study found out that the risk of infection by covid-19 in people who wear glasses may be twice to three times lower.  The research, conducted in India, was published in the website medRxiv.

Learn more about the preliminary work, how it was done, th results and next steps. It is worth noting the new investigations are necessary, but, as the disease is new, it is important to follow studies in the area.

 

Glasses and coronavirus: the research

 

The research evaluated 304 people, 223 men and 81 women, aging from 10 to 80, residents in Northern India, during two weeks.  Everyone presented symptoms of covid-19.

58 patients (19%) reported they frequently wore eyeglasses or sunglasses when exposed to sunlight.  Through a questionnaire, volunteers stated they touched the face 23 times and the eyes 3 times per hour, in average.

 

Glasses and coronavirus: results

óculos e coronavírus

 

According to the scientists, the results related to extended use of sunglasses were significant.  The current contamination rate of 1,35 of the population, in general, dropped to 0,48 among those who regularly wore glasses.  The calculated risk ratio, according to the study, was 0,36%.

That is, the chance of covid-19 infection dropped three times.

Researches believe that the low transmission ratio is due to two factors: glasses protect against contaminated droplets in the air and less frequent touches in the eye while wearing them.

 

Glasses and the coronavirus: Chinese resarch

 

A study carried out I n China and publish in the journal JAMA Ophthalmology in September 2020, pointed that wearing glasses for a long time reduces the chances of the new coronavirus infection by five times.

Scientists evaluated 276 positive covid-19 patients.  Factors are the same: less touches in the eyes and protection against airborne droplets.

 

Conclusion

In fact, scientists remark that the relation between wearing eyeglasses and the new coronavirus is still inconclusive.  This is because the study has not been revised by peers yet. Sampling was small and there was also difficulty to measure how long people wore glasses during the pandemic.

New investigations are necessary to evaluate the effects of glasses, such as protection against covid-19. However, as the disease is new, it is important to follow studies in the area.

 

Follow Phelcom’s blog and stay on top of main news in the area of eye care.

 

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