The Protecting Effect of Viscoelastic Material on Retinal Pigment Epithelial(RPE) Cells in Indocyanine Green(ICG)–Assisted Macular Hole(MH) Surgery

Abstract

Abstract: : Purpose: ; To evaluate the effects of viscoelastic material to prevent the RPE from the direct contacts with ICG during the MH surgery. Methods: Thirty one eyes with idiopathic MH underwent the vitrectomy combined with ICG–assisted internal limiting membrane(ILM) peeling and were divided into two groups depending on the use of viscoelastic material. After core vitrectomy and fluid–air exchange, a small amount of viscoelastic material was dropped to seal the the MH followed by an injection of about 0.2 mL of 0.05% ICG in thirteen eyes(group I) and same prcedures without the application of viscoelastic material was done in eighteen eyes(group II). After approximately 30 seconds, the ICG was aspirated first and then the viscoelastic material was carefully removed along with air–fluid exchange. The ILM around the MH was then peeled off using microforceps. Finally, all eyes were inflated with 20% SF₆ or 14% C₃F₈ gas and the patient were instructed to maintain a face down position for at least 7days. All patients were followed–up postoperatively at the time points of week 2, 3, 4, 6, 8, 10, 12 and then every one months and fundus images are obtained with an infrared camera(Zeiss, Germany) to compare the duration of fluorescence duration in the macula and disc area between two groups. Final visual outcomes and complications were evaluated as well. Mean follow–up period was 34.3 weeks in group I and 39.3 weeks in group II. Results: In group I and II, mean duration of macular fluorescence was 0.28 and 3.64 months, and mean duration of disc fluorescence was 4.46 and 5.09 months, respectively. Thus macular fluorescence duration in the Group 1 was significantly shorter than in Group 2(p=0.0001). But the difference in disc fluorescence duration was not significant between the two groups(p>0.05). Visual improvement more than two lines in group I and II was achieved in 61.5 %and 55.5%, respectively, without significant difference. As the postoperative complications, atrophic change of submacular RPE was observed in two eyes of each group. Conclusions: This study demonstrated that the use of viscoelastic materials would be an effective way to minimize the direct contact of ICG with the exposed RPE cells during the MH surgery and may protect RPE cells from the possible ICG–related toxicity.

Keywords: macular holes • retinal pigment epithelium • drug toxicity/drug effects