Explained | Why is glaucoma such a pain to catch?

Dr Malleswari Medikonda testing a affected person for glaucoma at Sankara Eye Hospital in Guntur.
| Photo Credit: T. Vijay Kumar/The Hindu

People with glaucoma go blind steadily, after which out of the blue. March 12-18 is World Glaucoma Week, noticed to improve consciousness of this severe risk to our imaginative and prescient. Glaucoma has no clear signs till its late phases, requires complicated diagnostic abilities to be recognized, and is usually masked by different eye situations. All this makes glaucoma a complicated situation to determine early.

What will we learn about glaucoma in India?

The Indian eye well being system has had exceptional successes in the previous few a long time. According to the newest knowledge from the Ministry of Health and Family Welfare (from 2019), the prevalence of imaginative and prescient impairment within the grownup inhabitants has decreased throughout the nation over 20 years. Tackling cataract and refractive errors – among the many most cost-effective well being interventions – is key to this success.

However, the highest 5 causes of blindness in India additionally embrace glaucoma, a persistent and age-related eye situation that has no remedy. It is a explanation for irreversible sight loss in adults that wants to be taken severely, and is troublesome to determine in the neighborhood. Estimates for the variety of folks with blindness due to glaucoma in India vary from 230,000 in adults over 50 in 2019 to 1.1 million folks (the latter estimate is from 2010). Worldwide, glaucoma is the second main explanation for irreversible blindness in adults older than 50 years, or round 3.6 million folks. Some 76 million folks have glaucoma world wide. 

A key drawback with our sense of glaucoma’s prevalence is that the variety of instances in India is seemingly being undercounted. About half of all folks with glaucoma go undiagnosed in high-income nations. In growing nations, greater than 90% who want medical consideration for his or her glaucoma don’t have entry to it. There are a number of causes for this example, every of which factors to the complexity of growing efficient pathways to display screen, diagnose, and handle this lifelong situation.

Why is glaucoma onerous to catch?

Glaucoma is a set of situations that harm the optic nerve and trigger peripheral imaginative and prescient loss, main to blindness. Vision can’t be restored as soon as it is misplaced on this manner as a result of the dying of the retinal ganglion cells, and the lack of their axons to the optic nerve, are everlasting. (These retinal cells are situated in the back of one’s eye.)

People with glaucoma haven’t any inkling of the harm to their optic nerve till there is imaginative and prescient loss, by when it is too late to catch the situation.

Glaucoma has complicated causes. Many genes are concerned, as are a number of environmental elements in its onset and development. (The extended use of steroid eye drops with out a prescription or past the prescribed time is additionally a widespread observe: such misuse may lead to glaucoma.) Glaucoma has additionally been linked to age, particularly amongst folks older than 40 years. It is additionally heritable.

How is glaucoma identified?

Glaucoma has no clear, outward indicators and requires particular checks to determine it. An knowledgeable will look at the entrance of the attention and test eye stress with a gadget referred to as a tonometer. To perceive the precise explanation for glaucoma, they are going to carry out a gonioscopy to view the angle at which the fluid drains out of the attention and maintains the stress inside. Then, the knowledgeable will look at the optic disc in the back of the attention. This check is essential to determine glaucoma and the extent of injury if it is current as a result of such harm is one of many first identifiable indicators of glaucoma.

Patients with glaucoma lose their peripheral imaginative and prescient, so a perimetry check is carried out to consider their visual field and set up the extent of loss. Imaging applied sciences like optical coherence tonometry give micrometer-scale photos of the attention’s inside, which will help consultants determine alterations and harm, generally sooner than a perimetry check would possibly spot a area defect.

Once a particular person is identified with glaucoma, therapy methods embrace eye-drops, lasers, and surgical procedure relying on the kind and stage of glaucoma. A affected person may have to transfer from one to the opposite to obtain long-term management over their lifetime. Vision misplaced to glaucoma is irrecoverable, so therapy solely stops additional loss. This means the imaginative and prescient for people who find themselves handled doesn’t enhance with therapy.

The situation has no clear indicators when it begins and any harm to the attention is irreparable.

Is there a complete answer?

The greatest technique is to diagnose glaucoma early. There is proof that neighborhood screening will help guarantee equitable entry to glaucoma care, particularly for ladies and the aged, who, within the eye care context, have a tendency to miss out on care. Networks of ‘vision’ centres, i.e. major eye-care centres, with teleophthalmology help can take fundamental screening and monitoring shut to these in want.

Adults older than 40 years, particularly these with a household historical past of glaucoma, should get a complete eye examination yearly, together with an examination of the retina and the optic nerve. If and when it is recognized, folks will want long-term monitoring and administration.

Those prescribed eye drops may have to take them daily for the remainder of their lives. The price of therapy – each day medicines, laser therapies, surgical procedures – will preserve consuming into their funds. The long-term pressures of glaucoma administration could also be overwhelming for most people, so tackling the situation would require each particular person and neighborhood motion.

Dr Sirisha Senthil is the pinnacle of the Glaucoma service on the L.V. Prasad Eye Institute. Tejah Balantrapu is affiliate director, Science, Health Data, and Story-telling, on the L.V. Prasad Eye Institute.