In the movie ‘Kuttrame Thandanai’, actor Vidharth plays Ravi, who is suffering from a rare non-preventable eye disease called Retinitis pigmentosa and needs money for his eye transplant, so he resorts to blackmailing two men into funding his surgery. He suffers from tunnel vision.

Glaucoma: The Silent Thief
The movie has a lot of factual errors. But that’s for a different day. Like yin and yang, there is a preventable blindness called Glaucoma that nobody talks about, and it also causes loss of peripheral vision. Loss of peripheral vision can be dangerous as we use it subconsciously and don’t know when and how we lost it. Bruce Lee’s fight scenes have always shown him looking out of the corner of his eye to attack multiple enemies. Imagine him losing it. But unlike Bruce, we don’t need it to fight but to walk/ride/drive. Our peripheral vision warns us of traffic/obstacles/dangers.

Understanding Glaucoma Symptoms and Diagnosis
To understand Glaucoma symptoms, a deep understanding of intra-ocular pressure is mandatory. Two fluids help retain the spherical shape of the eye, namely Aqueous Humor and Vitreous Humor. Aqueous Humor is a watery fluid produced in the eye’s back and exits via Schlemm’s canal in the front. Vitreous Humor is a gel in the back of the eye. Glaucoma causes and risk factors include shortsightedness, far-sightedness, high blood pressure, long-term usage of steroids (COVID saw a significant spike in Glaucoma), and diabetes mellitus. It sometimes runs in the family, especially from the mother’s side. If you have or are developing Glaucoma, you can or will have early signs and symptoms of a throbbing headache with or without nausea and vomiting, red, muddy eyes (read the previous month’s article on the same), constant change of glasses for near vision, halos around lights (like the ones you see around gods’ heads in movies). Don’t wait to rush to your ophthalmologist. He will, in turn, do some non-invasive, pain-free tests, which are very cardinal in diagnosing Glaucoma.

Treatment Options and Management
He will ask for a Visual acuity test and do a gonioscopy or anterior segment optical CT to see where the blockage is. Nowadays optical CT machines are so advanced that they can measure the thickness of your cornea. A thick cornea can also show fals high intra-ocular pressures. He will also check the eye pressure using an Applanation or non-contact Tonometer (typical pressure values are between 10-20 mmHg). Another important test is the visual field test which will gauge how much field of vision loss you have. Doctors will insist on a dilated slit lamp microscopy to see how the optic nerve is.In fact that’s how Glaucoma is diagnosed 1st Hand before all the complex investigations. The doctor will then determine the type of Glaucoma depending on the outcomes of all the tests.

Common types are primary open-angle Glaucoma or narrow or closed-angle Glaucoma. In children, it’s called Juvenile Glaucoma. Extensive steroid usage can lead to secondary glaucoma.

Once diagnosed and assessed for the amount of optic nerve damage, he will plan to stop further progression or salvage whatever vision is left. He can treat you medically with anti-glaucoma medications that increase the aqueous outflow. You might have to apply it lifelong meticulously. The other non-invasive method is called YAG PI or Trabeculoplasty. . Using a YAG laser creates another drainage channel on your Iris muscle. Newer innovations include an implant placed inside each eye that will dissolve the drug into your eye for a few months. Then, a replacement is required. Surgery is usually the last resort, and the surgeon will create a bypass for the Aqueous to flow out just like in cardiac bypass surgery. Ophthalmologists, too, use stents or valves. These surgeries are called MIGS or minimally invasive glaucoma surgeries. Once diagnosed and on medication, you must meet your ophthalmologist yearly and do a glaucoma workup. Maintain a dedicated file so the doctor can measure progress or regression parameters. In case you have seen floaters with sudden loss of vision along with a throbbing headache, then do rush to your ophthalmologist cause you might have malignant Glaucoma, which is a medical emergency. Requires hospitalisation as your intra-ocular pressures could touch up to 50 mmHg.

The last word
In the movie ‘Kuttramey Thandanai’, they could have chosen Glaucoma over Retinitis pigmentosa. Because over the age of 35, the risk of Glaucoma is high. Not many are aware of glaucoma. Early diagnosis and prevention are the way forward to prevent this preventable blindness. This movie could have helped raise awareness of this silent thief of vision. As World Glaucoma Day falls on 12th March, please don’t be silent but raise your voice against this silent thief of vision and spread the word.

• Dr Murugananth R
  Mbbs., Diploma in ophthalmology
  Senior Consultant eye surgeon