When Diabetic Eyes Are Lost to Follow-Up
Ophthalmology, March 2019
Although panretinal photocoagulation (PRP) greatly reduces the risk of severe vision loss from proliferative diabetic retinopathy (PDR), it has side effects that might be avoided by using anti-VEGF treatment. Studies of intravitreal injection of anti-VEGF agents have shown that this treatment produces similar (and possibly superior) outcomes, but strict adherence to the follow-up schedule is crucial. Little information exists on eyes that are lost to follow-up after either treatment. Obeid et al. compared anatomic and functional outcomes for eyes with PDR that were lost to follow-up for more than six months after treatment. They observed better outcomes for eyes treated with PRP than for those that received anti-VEGF injections.
For their study, the authors identified 59 patients (76 eyes) who were lost to follow-up immediately after treatment and returned more than six months later. Documented data included visual acuity (VA) and anatomic outcomes at the last visit before the patients were lost to follow-up, at their return visit, six months later, 12 months later, and at the final visit. The authors compared outcomes for the treatments, including functional changes that occurred between visits.
Of the 76 treated eyes, 46 underwent PRP, and 30 received anti-VEGF treatment. Results were as follows:
- In the PRP group, mean VA worsened significantly between the last visit before patients were lost to follow-up and when they returned (0.42 ± 0.34 vs. 0.62 ± 0.64 logMAR; p = .03). However, the difference in mean VA from the visit before being lost to follow-up to the final visit was not significant (0.46 ± 0.47 logMAR; p = .38).
- For the anti-VEGF group, the decline in mean VA was significant from the visit before being lost to follow-up to the return visit (0.43 ± 0.38 vs. 0.97 ± 0.80 logMAR; p = .001) and to the final visit (0.92 ± 0.94 logMAR; p = .01).
- At the final visit, the incidence of tractional retinal detachment and of iris neovascularization was higher in the anti-VEGF group. Four anti-VEGF eyes experienced iris neovascularization, and 10 experienced retinal detachment—versus none and one, respectively, of the PRP eyes.
These findings suggest that when patients are lost to follow-up, anatomic outcomes are better for PRP than for anti-VEGF treatment. Although the difference in functional outcomes also appears to favor PRP, the study lacked randomization. The authors recommend considering the sequelae related to follow-up noncompliance when selecting a treatment for PDR. They encourage studies of noncompliance predictors, which may help guide personalized treatment strategies. (Also see related commentary by Andrew P. Schachat, MD, in the same issue. For another study on this topic, see “After Anti-VEGF: When Patients Don’t Return.”)
The original article can be found here.