We appreciate Tan et al.
1 for their interests in our recent publication,
2 and we are glad to reply to the comments and questions raised in the letter. Although multiple injections of anti-VEGF drugs are necessary to treat diabetic macular edema (DME), frequent injections lead to the increased risk of ocular complications, including endophthalmitis and retinal detachment. Therefore, it is ideal to reduce the number of injections while keeping the high therapeutic effects. As they commented, the number of injections probably decreases after the first year; however, we consider that the 8 to 9 anti-VEGF injections still are frequent. Targeted retinal photocoagulation (TRP) for nonperfused areas (NPAs) would contribute to the further reduction of the number of anti-VEGF injections. In the aim to inhibit the production of VEGF, it is probable that the effect of anti-VEGF drug is transient, but that of photocoagulation for NPAs is permanent.
In our data, the recurrences of DME after injection were observed in the cases with the presence of residual or newly developed NPAs, despite the patients having the history of panretinal photocoagulation (PRP). This finding suggests the importance of the estimation of retinal ischemia by fluorescein angiography (FA) at adequate timing, and that the limited NPAs have a potential to induce the reswelling. We performed FA 6 months after initial treatment and found that enlargement of NPAs in the cases macular edema recurred. The TRP for NPAs is a primary therapy tool to suppress the VEGF production, and this tool should be considered before additional injection of anti-VEGF drug for the recurrence of DME.
As we and Tan et al.
1 commented, the additional laser treatment for peripheral NPAs that could be captured by ultrawild field (UWF) enhance the inhibitory effects of TRP for the recurrence. Although UWF is useful to estimate peripheral retinal ischemia, the addition of lasers in these peripheral lesions is not easy. Poor pupil dilation and severe shrinkage of anterior capsule opening (ACO) after cataract surgery are clinical problems in patients with diabetes, since they occasionally interfere with photocoagulation of the peripheral retina. To inhibit the contraction of ACO, we recommend the creation of a larger capsulorrhexis with the implantation of a 7-mm diameter intraocular lens.
3 Also, the treatment for postoperative inflammation is important, since the flare intensity at 1 week after cataract surgery is related to the degree of ACO contraction.
4
Finally, we hope that TRP contributes to reduce the frequency of the injections of anti-VEGF drugs, the costs, and ocular and general adverse events.