Ab-externo drainage with continuous anterior chamber infusion for non-resolving exudative retinal detachment: a case report

BACKGROUND: Drainage of exudative retinal detachment may be necessary for either therapeutic or diagnostic purposes (or both). Here, we describe an external drainage technique for non-resolving vision-threatening exudative retinal detachment which combines the advantages of internal drainage (widefield viewing and intraocular pressure control using continuous anterior chamber infusion) with those of external drainage (drainage of sub-retinal fluid without vitrectomy). CASE PRESENTATION: To illustrate this technique, we present a 13-year-old girl with macula-off exudative retinal detachment secondary to Vogt-Koyanagi-Harada syndrome, which was unresponsive to aggressive medical management. External drainage was undertaken using widefield viewing and chandelier illumination. Intraocular pressure was maintained with an anterior chamber infusion. Near-complete drainage of sub-retinal fluid was achieved, and retinal reattachment was maintained at 6 months postoperatively, with a corresponding improvement in visual acuity from 20/63 to 20/40. CONCLUSIONS: External drainage under chandelier-assisted viewing at the surgical microscope with anterior chamber infusion offers the ergonomic and optical advantages of the surgical microscope and widefield visualisation, continuous IOP control and drainage of sub-retinal fluid without the need for pars plana vitrectomy.