Ab interno management of blocked Ahmed valve in the posterior segment.
OBJECTIVE
To report a case of late failure of a posterior segment placed Ahmed valve in a uveitic eye with a corneal graft and a minimally invasive, ab interno approach in restoring valve function, pressure control, and preservation of vision.


METHODS
Case report.


METHODS
A 25 gauge trans-conjunctival 3-port pars plana vitrectomy was performed to inspect and clean the ostium of the Ahmed valve of any vitreous debris. The Ahmed valve was not disturbed externally and conjunctival dissection was not performed. A 27-gauge blunt cannula was introduced through the vitrector site and used to cannulate the tube and flush it with balanced salt solution. A bleb was immediately re-established and all instruments were removed requiring no sutures.


RESULTS
Intraocular pressure returned to target levels and a filtration bleb was re-established. Corneal graft clarity was restored with resolution of preoperative microcystic edema. Postoperative inflammation was minimal and vision was restored.


CONCLUSIONS
A nonfunctioning tube shunt residing in the vitreous cavity may be revised ab interno without disturbing the shunt placement or the conjunctiva under which it resides to re-establish filtration.
Manhattan Eye, Ear and Throat Hospital, New York, NY, USA. stevenodrich@gmail.com
Steven
S
Odrich
Kenneth
K
Wald
Laurence
L
Sperber
D002404:Catheterization / Q000379:methods; D004868:Equipment Failure; D020327:Glaucoma Drainage Implants; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000209:etiology* / Q000503:physiopathology; D013508:Ophthalmologic Surgical Procedures; D014065:Tonometry, Ocular; D014792:Visual Acuity / Q000502:physiology; D014821:Vitrectomy; D014822:Vitreous Body / Q000601:surgery