What is a Macular hole?
A macular hole is a small gap that opens in an area of the eye called the macula. The macula is responsible for central vision we need for tasks such as reading, driving, and seeing fine detail. An operation known as a vitrectomy is the treatment for a macular hole. The eye is filled with a temporary gas bubble, which presses the hole flat onto the back of the eye to help it seal.
Why carry out the PIMS trial?
Since the surgery was first described around 25 years ago, patients have been advised to maintain a face-down position, known as posturing, for up to 10 days following surgery to help the gas bubble stay in place. However, there is little hard evidence to support the benefit of posturing. This has led to wide variation in the advice given to patients, with some surgeons abandoning the practice altogether.
Review of the existing evidence
Professor James Bainbridge, Consultant at Moorfields Eye Hospital, along with the Cochrane Eyes and Vision Group conducted a Cochrane review. During the review they looked at the existing evidence relating to posturing after macular hole surgery.
Only three studies out of 266 met the high standards required for inclusion. The review concluded that face-down posturing did not improve repair of small macular holes. However, some improvement was seen in the repair of large holes. The data were insufficient to draw firm conclusion, this highlighted a need for more robust evidence to guide doctors.
Listening to the public voice from the start
In 2012, a national initiative called The James Lind Alliance Sight Loss and Vision Priority Setting Partnership, identified that research into ways to improve the treatment of macular hole was a priority for patients. Posturing can be very difficult for patients, particularly as macular holes are more common in people aged over 75 years. These patients are more likely to suffer with joint disorders such as arthritis making face-down posturing awkward or even painful. Posturing also carries a small but serious risk; some people could experience nerve compression or a blood clot.
The PIMS trial begins
To address these public and clinical priorities, Professor Bainbridge conducted a successful pilot study and is now running the PIMS (Posturing in Macular Hole Surgery) trial. Patients have played an important part in helping researchers in the design of this research. Find out how here.