It is always nice to see a new drug become available for a condition for which there has been no previous treatment. I am, therefore, happy to write about a new drug that has just become available for the treatment of Vitreomacular Adhesion (VMA). Never heard of VMA? Most people haven’t, but it does happen to a lot of people. Let me explain.
As we age, the vitreous, the gel-like substance at the back of the eye, becomes detached from the retina and pulls away from it. This is a normal process and occurs in about 75% of people over the age of 65. In most cases, nothing serious happens except for a few symptoms associated with this vitreous detachment – sometimes flashes of light may occur and often there are more floaters in the eye than usual. If these are excessive, one should consult an eye doctor.
However, in a small number of cases, a small amount of the vitreous may remain attached to the retina, in the area of the eye where light focuses, called the macula. The attached vitreous may cause extra traction on the macula resulting in some fairly serious side effects. In particular, it may cause a small hole in the macula (macula hole) that can lead to sight loss if untreated. While there is no data on the incidence of macular holes in Canada, a U.S. based study estimated the incidence of macular holes at 7.8 people per 100,000 per year.
The current treatment for VMA is surgery in which the vitreous is removed from the eye, thereby removing the potential damage that may be caused by traction due to the adhering vitreous. This surgery is quite successful but does have the potential for some serious side effects. Some of these complications can include detachment or tearing of the retina; an infection within the eye; or the development of cataracts post-surgery.
There is now a new drug, just approved by Health Canada for marketing in Canada, called ocriplasmin (trade name Jetrea) that eliminates the need for surgery in many cases of VMA. Jetrea is injected into the vitreous of the eye and causes the part of the vitreous that is adhering to the retina to come away from the retina. In those cases where it works, there is no further need for any surgery. The potential for some of the side effects I have mentioned, as well as the personal burden associated with undergoing surgery, are thereby eliminated as well.
It’s wonderful to see a new medication come to the market with the potential to prevent sight loss, but, just a word of caution, as with all new drugs, Jetrea will not work in all patients, but it will make a substantial difference to those for whom it does work.