A Medical Device Daily

Telemedicine has a “significant” role to play in the diagnosis of eye diseases, increased patient compliance and patient access to quality care, according to two studies presented at the American Aacademy of Ophthalmology’s (AAO; San Francisco) 2007 annual meeting this week.

Telemedicine is a rapidly developing application of clinical medicine where medical information is transferred via telephone, the Internet or other networks for the purpose of consulting, and sometimes remote medical procedures or examinations.

The first study had researchers examining the impact that telemedicine had on patients with diabetes being treated in multi-physician primary care practice. The study looked at the number of patients with diabetes throughout the course of a year who had the recommended retinal examination before the installation of a telemedicine remote imaging system in the practice vs. the number of patients with diabetes who had a retinal examination in the two years following the installation of the device.

In the first year out of 1,257 diabetic patients in the study, only 15% had a retinal examination. Two years after implementation of the telemedicine system, 71% of the 1,395 diabetic patients in the practice had a retinal examination. Significantly, of the observed increase, 66% was due to an eye examination by a local ophthalmologist and only 33% was due to remote evaluation.

“It’s very nice to see that increased rate of evaluation was not solely because these patients were undergoing remote imaging,” said Ingrid Zimmer-Galler MD, an assistant professor of ophthalmology at the Wilmer Eye Institute at the Johns Hopkins School of Medicine (Bethesda, Maryland).

In a second study presented at the annual meeting, researchers concluded that there was a high level of agreement between diagnoses of retinopathy of prematurity (ROP) made in low birth-weight babies using opthalmoscopy and imaged-based telemedicine examinations.

Doctors at the Columbia University (New York) College of Physicians and Surgeons gathered data on 206 eyes from 67 prematurely born infants, performing up to two sets of examinations on each baby. In each instance, a pediatric ophthalmologist performed dilated indirect ophthalmoscopy on the infant to determine whether the baby had ROP.

Diagnoses were classified in four categories: no ROP, type 2 prethreshold ROP, and treatment-requiring ROP. Shortly after the physcian’s examination, a trained nurse captured retinal images of the same child using a wide-angle camera. A period of up to 12 months was allowed to elapse before images were shown to the same doctor who performed ophthalmoscopy, in order to minimize any chance that the examiner could remember details.

In 86% of the eyes, there was complete agreement between the diagnoses made by ophthalmoscopy and telemedicine. Among eyes where there was disagreement between the examination modalities, 12 cases involved clinically-significant discrepancies regarding presence of zone I disease or plus disease.

In other news from the AAOS meeting:

• Clinicians from Villa Serena Hospital (Forli, Italy) unveiled a modified version of descemet-stripping automated endothelial keratoplasy (DSAEK), a procedure for treating patients with endothelial disease of the cornea.

The disease occurs when cell density in the endothelial layer is reduced below a level compatible with its normal function, the cornea swells and becomes less transparent, and vision is impaired. Since endothelial cells do not regenerate, the disease is treated by transplanting healthy donor tissue. The standard approach has been complete cornea transplantation (PK, or penetrating keratoplasy).

The DSAEK procedure, where only endothelial tissue attached to a thin layer of deep stroma is transplanted and the normal structure of the recipient cornea is not disrupted, is increasingly preferred by corneal surgeons. Most patients receiving DSAEK recover good vision within weeks (vs. six months to a year with PK), and the risk of complications during and after surgery is minimized. A significant drawback of DSAEK, though, has been the limited survival of the transplanted endothelium, with a reduction of up to 50 % of preoperative density as early as six months after DSAEK.

• A new study presented at the meeting shows that laser surgery can help improve and possibly stabilize the vision of patients who have radial keratomy (RK) while preventing previously common side effects from the surgery such as haze.

In the study, 22 patients who had previously undergone RK and subsequently developed unanticipated changes in prescriptions for correcting vision underwent advanced surface ablation with miomycin C, an anti-scarring medication.

“This gives new hope to patients who have had RK and have developed problems,” said Navaneet Borisuth, MD, PhD, the presenting author of the poster. “Most refractive surgeons would shy away from these patients because we were not able to deliver the results that they expected. Now, with this refinement, we can deliver a very good quality of vision for our RK patients.”

Before the advent of laser surgery, RK was the predominant method of surgically correcting nearsightedness in patients. The procedure involved a surgeon making small incisions in the cornea, thus relaxing it and flattening it, which in turn corrected myopia. However, some patients developed farsightedness, or hyperopia, as scarring around the incisions caused the cornea to tighten and further change its shape. Efforts to correct this problem with laser technologies, such as photorefractive keratectomy (PRK) or LASIK, were fraught with complications and were often unsuccessful.