Background: During macular hole surgery, indocyanine green (ICG) has access to the subretinal space and can lead to toxic and phototoxic damage of the retinal pigment epithelium (RPE). To reduce its toxicity and to avoid contact between ICG and the RPE, we have developed a modified technique by using autologous whole blood.
Methods: Thirty-one eyes underwent vitrectomy for idiopathic macular hole repair. Autologous whole blood (0.1 ml) was injected into the buffered saline solution (BSS)-filled vitreous cavity over the posterior pole and aspirated with a flute cannula. A small clot remained covering the macular hole. The internal limiting membrane (ILM) was stained by using 0.05% ICG solution. The ICG was dissolved in 5% glucose to obtain an iso-osmotic solution. This ICG was injected into the BSS-filled vitreous cavity over the posterior pole and removed after 10 s. The ILM was peeled and a long-acting gas tamponade applied. Pre- and postoperative best-corrected visual acuity and optical coherence tomography (OCT) findings are reported.
Results: Macular hole closure was achieved in 30 of 31 eyes (97%). The mean preoperative logMAR acuity was 0.99 (range: 0.4 to 2.0). Mean postoperative logMAR acuity was 0.496 (range: 0.0 to 1.0). The average improvement in vision was 0.66 logMAR units (range: 1.5 to 0.0). No postoperative RPE alterations were observed biomicroscopically or on OCT.
Conclusion: This surgical technique leads to favorable anatomic and functional results. ICG toxicity is reduced by modifying osmolarity, concentration and contact time and by injecting ICG under BSS. Autologous whole blood acts as a mechanical barrier and prevents ICG from entering in the subretinal space.