London-Adherence of patients with glaucoma to their follow-up appointments prior to trabeculectomy can be used to predict the outcome of the surgery, according to the results of a retrospective study presented by Ian A. Rodrigues, MBBS.
Dr. Rodrigues and colleagues investigated a possible relationship between follow-up appointment adherence (FAA) and long-term trabeculectomy success using data from 80 eyes of 74 patients. The cases were identified from a series of 100 consecutive mitomycin-C augmented trabeculectomies performed/supervised by a single surgeon and represented patients with at least 12 months of follow-up after surgery; mean postoperative follow-up was 4.7 months. Information on appointment adherence was retrieved from electronic records.
At last follow-up, about 70% of patients were categorized as achieving surgical success, defined by IOP of 15 mm Hg or less with or without topical medications. Compared with the surgical success group, patients who were classified as having surgical failure had significantly lower FAA rates both preoperatively (87/1% versus 92.0%, p = 0.019) and postoperatively (89.7% versus 93.4%, p = 0.033). In addition, patients with an FAA rate <92% had nearly a four-fold higher, significantly increased risk for trabeculectomy failure than their counterparts who met this threshold that represents the national average for FAA rate among glaucoma patients in the United Kingdom.
“Although it seems logical that there is a relationship between FAA and outcome of trabeculectomy surgery, to our knowledge there are no previously published studies providing evidence to support this assumption. In clinical practice, it is difficult to know whether patients sitting in your chair are using their medications, but we feel FAA rate may be a surrogate measure of treatment compliance and therefore can explain how just a small difference in number of appointments attended could have such a significant effect on trabeculectomy outcome,” said Dr. Rodrigues, ophthalmologist in training, King’s College Hospital, London.
“Our analyses also showed that patients who had low FAA rates preoperatively had low FAA rates after surgery,” he said. “Taking all of our findings together, we believe our study suggests that by looking at appointment adherence rate preoperatively, clinicians may identify patients warranting an intervention strategy to increase compliance and give them a greater chance of success with trabeculectomy surgery.”
The study group comprised a slight majority of women (53%) and had a mean age of 67 years at the time of surgery. Afro-Caribbeans and Caucasians accounted for nearly all patients and the two racial-ethnic groups were about equally represented. About 75% of patients had primary open-angle glaucoma and almost 11% had previous trabeculectomy surgery.
Data on preoperative FAA were available for a mean period of about 7 years, and mean IOP at the time of trabeculectomy was 26.4 mm Hg. Mean IOP at last postoperative follow-up was 13.4 mm Hg, and the majority of patients were using topical medications.
For the overall study group, the FAA rate was 90.4% during the preoperative period and 92.5% postoperatively. There was no significant difference between the preoperative and postoperative FAA rates for individual patients, said Dr. Rodrigues.
Additional analyses considered appointments that were not attended because they were cancelled/rescheduled by the hospital or patient and total missed appointments. However, no relationships were found between these variables and trabeculectomy outcome.
Discussing the background for the study, Dr. Rodrigues noted that because glaucoma is a chronic disease, its management involves a lifelong partnership between doctor and patient. Treatment nonadherence remains a major challenge faced by physicians in providing glaucoma care.
“All the physician can do is initiate treatment and encourage patients to use their medications. However, it is ultimately up to the patient to use the drops,” he said.
“Worsening disease often occurs because medical therapy is not being used properly, and trabeculectomy is often the next step for managing medically uncontrolled glaucoma,” he said. “However, despite recent technical advances in the surgery, including use of mitomycin-C and postoperative interventions, the long-term success of trabeculectomy is still challenging.”
Dr. Rodrigues observed that patient compliance with the postoperative care regimen is as critical as surgical technique in determining trabeculectomy outcome.
“Postoperative care involves intensive treatment regimens and frequent follow-up visits. Treatment adherence with medications is difficult to measure in clinical practice, but appointment adherence is accurately recorded,” he said.
Dr. Rodrigues has no relevant financial interests to disclose.
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