DURHAM, N.C. -- Researchers at the Duke Eye Center have determined that patients with age-related macular degeneration (AMD) experience significant improvement in their quality of life following a surgical procedure called "macular translocation with 360 degree peripheral retinectomy" (MT360). AMD is an eye disease that may lead to vision loss in the central region of a person's visual field, a defect that can seriously impact a patient's quality of life.
The macula -- located at the center of the retina, the light-sensitive tissue lining the back of the eye -- is particularly critical for activities that require detail vision, such as reading or sewing.
Very little data exists regarding quality of life (QOL) of patients with advanced vision loss from AMD, the researchers said. For this reason, they chose to compare QOL in their patients with severe AMD against QOL data from other studies of people with milder effects of AMD or other eye diseases. From this data, they determined a baseline reading of their AMD patients' overall quality of life. Armed with a better understanding of the QOL issues faced by their patients, they performed a second study in which they compared quality of life in patients before and after MT360 surgery for severe AMD. The findings from both studies appear in the January 2005 issue of Ophthalmology.
"We can now show, scientifically, that our patients have been able to improve not only their central vision, but their quality of life as a result of the visual improvements following MT360," said Cynthia Toth, MD, senior author of both studies, an associate professor of ophthalmology and an eye surgeon at Duke. "The data show patients improve not only in tests of visual acuity done in our office but also in their everyday lives. Does improving visual acuity improve quality of life for the patient? Yes, it does, and we didn't know for sure until now."
MT360 is a two-stage surgery that involves first internally rotating the retina to shift the degenerating macula to a healthy area, away from abnormally growing blood vessels and scar tissue. The surgical shift begins to restore function to the macula. In the second stage, the eye is rotated to account for the ensuing tilt in a person's visual field. The research team had long believed their patients' quality of life would naturally improve along with improvements to their central vision. But until now, the researchers said, they have lacked scientific support outside the realm of in-clinic visual testing.
"As clinicians, we must recognize the importance of patients' overall quality of life when we speak to them about what is going on with their vision, because to the patients this is what is most important," said Toth. "A number that represents their visual acuity improvement is great for me as a surgeon, but may be meaningless to my patients. What matters is how this better number will translate into a better life for them at home."
In the first set of data collected, the team surveyed 70 patients with severe age-related macular degeneration in both eyes who were schedule for MT360 surgery. The responses of the severe, bilateral AMD group were compared against three other groups: patients with AMD of varying severity, patients with low-vision (due to various ocular causes) and a control group of patients without ocular disease. The research group found QOL measurements in patients with severe, bilateral AMD to be similar to patients in the low-vision group but worse than those with AMD of varying severity and worse than those without ocular disease.
The most important finding, the researchers said, is the clear demonstration of the impact of central vision loss on patients' ability to perform vision-related activities such as reading the newspaper, seeing well up close and navigating around their home and neighborhood. Furthermore, patients with bilateral, severe AMD experience a great deal of isolation, which is manifested as a loss of independence, increased problems in social interactions and increased levels of anxiety, the researchers added. Although patients with bilateral, severe AMD had general health QOL scores comparable to their peers, their vision-related quality of life scores were much lower and were not related to general health problems.
In the second study, the team analyzed data from 50 patients who had completed questionnaires about QOL both before, and one year after, MT360 surgery. The research team compared pre- and post-operative QOL survey results and determined that MT360 is associated with improvement in vision-related QOL, and that improvement is not associated with changes in the general health of the patient. Further, the research team learned that the greatest improvement in QOL appeared in those with the greatest improvements in visual function following the surgery.
"These findings are very reassuring to me as a surgeon and caregiver," said Sharon Freedman, MD, associate professor of ophthalmology at Duke and an author on one of the studies. "Asking the right questions is important. How do visual improvements translate into improvements in everyday life for our patients? MT360 and the subsequent eye muscle surgery represent an aggressive surgical approach – far more aggressive than simply providing low-vision aids to our patients with AMD. A successful surgery is not enough – we continue to manage each of our patients with a distinct team approach to make sure he or she can maximize their improvement."
Not all patients with AMD are considered candidates for MT360, the researchers emphasized. The best candidates are those who have central vision loss in both eyes and who have experienced recent vision loss – specifically within the previous six-months – in their second eye. While vision may be improved following the surgery, there is no cure for AMD, one of the leading causes of blindness in Americans over the age of 65.
"We are not done yet," Freedman added. "We continue to refine our surgical techniques and our understanding of our patients. Our goal is to maximize not only the quantity of vision preserved or restored, but also the improvement in our patients' quality of life."
Research funding for both quality of life studies was provided by Euan and Angelica Baird and The Andrew Family Foundation -- all benefactors of Duke Eye Center. Additional support was provided by the National Institutes of Health.
Sandra Stinnett, DEC, and Avie Banks, formerly of DEC, are authors on the papers. Mark Cahill, a vitreoretinal surgeon and former associate at DEC, is first author of both studies. Cahill now practices in Ireland.
