How early diagnosis can prevent millions from losing their sight – Firstpost

Blindness remains a significant global health challenge with millions vulnerable due to preventable or treatable conditions. Globally, the primary causes of vision impairment and blindness are refractive errors, cataracts, diabetic retinopathy, glaucoma and age-related macular degeneration.

According to WHO only 36% of individuals with distance vision impairment due to refractive error and 17% of those with vision impairment due to cataracts have accessed appropriate interventions.

As per the reports, at least 2.2 billion people worldwide suffer from near or distant vision impairment, with approximately 1 billion cases being preventable or yet to be addressed. The leading causes of distance vision impairment or blindness among these 1 billion individuals are cataracts (94 million), refractive error (88.4 million), age-related macular degeneration (8 million), glaucoma (7.7 million), and diabetic retinopathy (3.9 million).

In an insightful conversation with Firstpost, Dr Uday Tekchandani, Consultant Ophthalmologist, Vitreoretina, Uveitis and ROP Specialist, Dr Agarwals Eye Hospital (Wadala) talked about the leading causes of blindness, the importance of early diagnosis and the significant strides made in neonatal care particularly concerning Retinopathy of Prematurity (ROP).

What are the leading causes of blindness today, and how can they be reduced?

Dr Tekchandani: The leading causes of blindness include cataracts, diabetic retinopathy, macular degeneration and glaucoma. Cataracts can be treated with surgery, which involves replacing the cloudy lens with an artificial one. Refractive errors can be corrected with glasses, contact lenses or surgical options like LASIK and SMILE.

Diabetic retinopathy, a potentially blinding condition, can be treated with laser therapy, intravitreal injections, surgery and most importantly, by maintaining effective blood sugar control. Depending on the specific type of the disease, macular degeneration can be treated with oral medications and injections. Glaucoma, a preventable cause of irreversible blindness can be controlled with eye drops, laser therapy or surgery in advanced cases.

How important are early diagnosis and regular eye check-ups in preventing blindness, especially for at-risk populations?

Dr Tekchandani: Early diagnosis is critical for effectively treating blinding eye diseases. Every child should undergo a comprehensive eye checkup by school age, or earlier if there are any visible issues or signs, such as white discoloration in the eyes.

Adults over 40, especially those with a family history of glaucoma, should have regular screenings, as untreated glaucoma can lead to irreversible blindness. Additionally, anyone diagnosed with diabetes should see an eye doctor for a retinal exam immediately after diagnosis to detect and manage diabetic retinopathy before it reaches more severe stages. Timely screenings and proactive care are vital in preventing most blinding eye diseases, which are often avoidable with early intervention.

What are the most common causes of blindness and visual impairment worldwide? 

Dr Tekchandani: The leading causes of blindness include cataracts, diabetic retinopathy, macular degeneration, and glaucoma. However, the most common cause of visual impairment worldwide is uncorrected refractive error, which refers to the need for corrective lenses or spectacles.

Can you explain what Retinopathy of Prematurity is, why it primarily affects premature infants and how can early detection and intervention improve outcomes for premature infants?

Dr Tekchandani: Retinopathy of prematurity (ROP) is a condition that affects the retina of prematurely born babies and can lead to irreversible blindness by the time the child is six months old. Because these infants are born prematurely, their retinal blood vessels are not fully developed at birth. As the child grows outside the womb, differences in the environment can hinder normal blood vessel development and lead to the formation of abnormal blood vessels. This can cause bleeding and tension on the retina, resulting in retinal detachment.

ROP can occur in any baby born weighing less than 2 kg or born before 34 weeks of gestation.

Additionally, older and heavier babies who require oxygen after delivery, have had blood transfusions, or suffer from systemic infections may also develop ROP. Treatment options for retinopathy of prematurity include laser therapy or intravitreal injections of anti-VEGF medications, depending on the stage and severity of the disease. In advanced cases, surgical intervention under general anesthesia may be necessary.

Parents must ensure that their baby if born before 34 weeks of gestation or weighing less than 2 kg, is evaluated by a trained ROP specialist before reaching four weeks of age. If the child is older or heavier and the pediatrician suspects any health issues, screening and follow-up for ROP should also be conducted according to national guidelines. It is important to understand that by the time parents notice problems with their child’s eyes—such as white discoloration or difficulty seeing—there may be very little that can be done to restore vision.

What advancements have been made in treating ROP and how can neonatal care facilities better address the challenges of diagnosing and treating ROP in developing countries?

Dr Tekchandani: Retinopathy of prematurity (ROP) was initially treated solely with laser therapy, and surgical outcomes for affected children were often poor. Today, newer injections are available that can be administered directly into the child’s eye to treat ROP. Advances in surgical techniques, such as small incision vitrectomy, along with improved surgical equipment, have significantly enhanced surgical outcomes for children with this condition.

Moreover, advancements in neonatal care, particularly in administering general anaesthesia safely to these vulnerable infants, have played a crucial role in preventing blindness. It is essential for neonatal care facilities to adhere to guidelines for providing oxygen and quality care for at-risk neonates. Additionally, timely screening by a trained ophthalmologist for ROP is critical to ensure early detection and intervention.

Are there any breakthrough therapies or innovations in gene therapy or stem cell research that could help restore vision for people with degenerative eye conditions?

Dr Tekchandani: For patients suffering from retinitis pigmentosa or genetic night blindness, there is a treatment available for those with a specific genetic mutation known as RPE65. This treatment involves an eye surgery in which injections are administered inside the eye to help improve vision.

How critical is early screening for preventing blindness in children, and what steps can parents and caregivers take to ensure timely detection?

Dr Tekchandani: Things parents should know about child eye health

• Screen Time: Limit screen time as much as possible. For children under 1-2 years of age, any screen time should be restricted to essential video calls. For children over 2 years old, limit screen time to educational activities. Excessive screen time can lead to digital eye strain, progressive refractive errors, and various health issues such as social anxiety, attention deficit hyperactivity disorder (ADHD), and obesity.

• Safety Precautions: Keep chemicals and sharp objects out of reach of children to prevent accidents.

• Eye Exams: Every child should have their eyes examined by an ophthalmologist once they start school. This helps diagnose any refractive errors and prevent amblyopia (lazy eye). Early signs that warrant screening for refractive errors include difficulty distinguishing between similar-looking objects or numbers, getting too close to the blackboard or objects to read, and squinting to see better.

• Abnormal Eye Symptoms: Any abnormal discoloration of the eyes, such as a white or yellow reflex at any age (even in newborns), or any deviation of the eyes (squinting) should prompt immediate consultation with an ophthalmologist, as these can indicate serious conditions like childhood cataracts or even eye cancer.

• Movement and Vision Issues: Difficulty navigating in unfamiliar environments, bumping into obstacles, or struggling to see in daylight or at night may be signs of genetic eye diseases.

• Allergies: Redness and itching of the eyes can be signs of eye allergies. It is essential to consult an ophthalmologist for appropriate eye drops to prevent allergies from progressing into serious conditions like keratoconus, drooping eyelids, or corneal infections.

• Outdoor Activities: Outdoor activities in natural sunlight for at least 90 minutes per day are important for eye development and can help prevent rapid progression of refractive errors.

• Premature Infants: Every child born prematurely (before 34 weeks of gestation) and weighing less than 2 kilograms must be examined by a trained ophthalmologist by 30 days of life to screen for retinopathy of prematurity, a preventable cause of irreversible blindness.

Can you share some statistics on ROP concerning India?

Dr Tekchandani: India contributes approximately 10% of all Retinopathy of Prematurity (ROP) cases globally. Up to 32% of at-risk infants screened have some form of ROP. Among these, 18% of at-risk infants screened have severe ROP, which may require laser treatment, injections, surgery, or a combination of these interventions. The most common reason for children presenting late with advanced stages of ROP is a lack of awareness about the disease and the importance of timely screening and treatment.