New Delhi: An eye drop that promises to replace reading glasses for a majority of people with presbyopia—an age-related blurry eye condition which makes it difficult to focus on nearby objects—was launched in India Tuesday, two years after the launch of a similar eye solution in the US. This is the first such eye drop to enter the Indian market.
The eye drop, launched under the brand name PresVu by Entod Pharmaceuticals, a Mumbai-based pharmaceutical firm that specialises in ophthalmological drugs, contains 1.25 percent pilocarpine hydrochloride as the active pharmaceutical ingredient (API) .
Pilocarpine is a plant-derived compound that has been used for decades to treat various eye conditions and dry mouth, and reduce eye pressure, among other applications.
It is meant to treat presbyopia, which typically impacts people over 40 years of age.
The formulation is similar to the one used in Vuity eye drop by Allergan, an AbbeVie company headquartered in Dublin, Ireland. Vuity hit the US market in 2022 following regulatory clearance by the US Food and Drug Administration (FDA).
Entod hopes to make PresVu, which can be bought by patients only when prescribed by an ophthalmologist, available in pharmacies across India by October, Nikhil K. Masurkar, CEO of Entod Pharmaceuticals, told ThePrint. He added that it will mostly be beneficial to those aged 44-55 years or people with primary to intermediate presbyopia.
It is estimated that nearly 45 percent of Indians aged 40 and above have presbyopia, with some studies estimating its prevalence to be high as over 75 percent.
A vial of the eye drop, containing 5 millilitres of the drug, is slated to cost Rs 345 and expected to last about a month.
The drug had received marketing authorisation approval from the Drugs Controller General of India (DCGI) last month following phase 3 clinical trials conducted with nearly 250 patients. Masurkar said the number of patients on whom the eye drop was tested was less compared to the most other late stage trials. This was because it was a repurposed drug.
ThePrint explains how the drug can help you put away the eye glasses and whether this can be a long term solution for vision problems.
How it works
Presbyopia affects short-range eyesight and mainly occurs when the eyes’ lenses lose their flexibility as the person ages. They may also harden when the person is in their early 40s.
Presbyopia is managed with glasses, contact lenses and surgeries such as refractive lens exchange, a technique which replaces eyes’ hard lenses with new artificial intraocular lenses.
One must apply only one drop of PresVu to each eye every day. The medicine will work by reducing the size of the pupil, which contracts certain muscles in the eye to help people see up close. The API in the eye solution is a cholinergic agonist—a group of medicines that mimic the actions of acetylcholine, one of the most common neurotransmitters in the human body that is also linked with the functioning of key muscles in the eyes.
Pupils dilate or widen to allow more light to enter the eyes in dimly lit places. When exposed to bright light, the pupils constrict.
With the help of the API in the eye drop, the pupils can be constricted even further, allowing fewer rays of light to make it to the back of the eyes. Constricted pupils have greater light converging ability, and this will help reduce blurriness in the eyes when viewing nearby objects.
One muscle responsible for changing the size of the pupils is the iris sphincter muscle, which is sensitive to certain chemicals, including pilocarpine 1.25 percent. It basically guides the iris sphincter muscle to contract, making the pupils smaller. This helps the eyes focus on objects that are close to the eyes.
However, the drug has no impact on near-sightedness or myopia, a condition in which one cannot clearly see objects beyond a distance of 25 centimetres.
PresVu’s effects are only temporary, and the effect of the drug lasts for about 6 hours and an additional drop, to be put about 3-6 hours after the first drop, can extend this duration by three more hours. The eye drop promises to show results within 15 minutes of application but best results can be seen only after nearly 15 days of sustained use.
Masurkar said that a key distinction between Vuity and PresVu is the type of adjuvants, which refer to components in a solution apart from the API.
Also, results from the trial have shown that it will be beneficial mostly to people aged 40-55 years and not in people with severe presbyopia. Adjuvants in PresVu have been added keeping in mind the Indian population, which has more pigmented irises, Masurkar said.
Long term-solution for presbyopia?
Results from clinical trials of PresVu in the Indian population have not been made public.
The FDA said that no concerning adverse events were observed in any clinical study participant on whom Vuity was tried. But the most common adverse events (in less than five percent of the participants) were headache and eye redness.
Other reported side-effects in 1-5 percent of patients who used the eye drop were altered or blurry vision, eye irritation, eye pain and watery eyes.
Importantly, the FDA also said rare cases of retinal tear and retinal detachment—a serious eye condition in which a part of the eye (retina) pulls away from supportive tissue—have been associated with use of miotics (drugs that cause pupils to contract), including Vuity.
A senior ophthalmologist with the All India Institute of Medical Sciences (AIIMS) in Delhi, who requested anonymity, told ThePrint that while the eye drop sounds promising, and pilocarpine is a trusted eye solution for many conditions, it remains to be seen whether the compound can be a choice of treatment for people with presbyopia. “That is because we don’t have long term safety data on the use of the formulation for blurry vision.”
(Edited by Radifah Kabir)