Managing high risk glaucoma with the Ahmed valve implant:20 years of experience

AIM： To estimate the efficacy and safety of the Ahmed implant in patients with high risk for failure after glaucoma surgery.METHODS： In 342 eyes of 342 patients with refractory glaucoma, even with application of medical treatment, the Ahmed valve was introduced for intraocular pressure（IOP） control, in the period of the last 20y. The nature of glaucoma was neovascular in 162 eyes, pseudophakic or aphakic in 49 eyes, inflammatory in 29 eyes and non working previous antiglaucomatic surgical interventions in 102 eyes. RESULTS： Follow-up ranged from 18 to 120m o with a mean follow-up of 63.2m o. IOP before the operation decreased from 31.6±10.4 mmHg to 18.3±5.4 mm Hg（no systemic treatment） at the end of follow up period. When we compared the IOP values before the operation using ANOVA showed statistically significant difference（P〈0.001）. The success rate was 85.2% during the first semester, 76.8% at 12 mo and 50.3% at the end of follow up period（18 to 120 mo after implantation）. Success rate was 25.7% in neovascular glaucoma, 63.2% in aphakic glaucoma and 73.8% in non working previous antiglaucomatic surgical interventions. Complications due to the implant were： serous choroidal detachment in 14.8%, blockage of the tube in 2.8%, malposition of the tube in 4.9%, suprachoroidal hemorrhage in 2.1%, cataract progression in 39.6%（phakic eyes）, shallow anterior chamber in 9.2%, hyphaema in 28.9%, exposure of valve in 2.6%, exposure of tube in 9.3%, hypotony in 4.9% and conjunctival fibrosis in 41.5%.CONCLUSION： Despite the fact that Ahmed valve implant had suchlike results as other implants concerning the IOP control, complications rate due to hypotony or over filtration in the first days after the intervention are not that frequent as with other valve implants.

Treatment of anterior corneal scarring,following DSAEK graft failure,with combined graft exchange and phototherapeutic keratectomy

Background:To present a method,alternative to penetrating keratoplasty,for the restoration of impaired corneal clarity with anterior stromal scarring following long-standing corneal graft failure.Case presentation:A 48-year old female who had previously underwent Descemet stripping automated endothelial keratoplasty(DSAEK)for the treatment of pseudophakic bullous keratopathy,presented with longstanding corneal oedema and anterior corneal scarring.A significant improvement in corrected distance visual acuity was demonstrated,as corneal clarity was restored following graft exchange and phototherapeutic keratectomy(PTK).Conclusions:The combination of corneal graft exchange and phototherapeutic keratectomy may represent an effective therapeutic option for long-standing corneal oedema with concomitant anterior corneal scarring after failure of a DSAEK graft.

Surgical management of spontaneous,lateonset Descemet membrane detachment after penetrating keratoplasty for keratoconus:a case report

Background:To report a surgical method for treating corneal oedema in a case of late-onset Descemet membrane detachment after penetrating keratoplasty.Case presentation:A 55-year old patient presented with sudden visual loss in his left eye 28 years after penetrating keratoplasty for keratoconus.Slit-lamp biomicroscopy revealed a distortion of the corneal graft anatomy with protrusion of the graft and peripheral thinning and steepening in the residual host tissue,accompanied by corneal graft oedema.Anterior segment optical coherence tomography revealed detachment of Descemet membrane localized to the area of the graft oedema.We proceeded with a full-thickness,partially circumferential incision in the graft-host junction,followed by repositioning and re-suturing of the graft in place,and intracameral air injection in order to achieve reattachment of Descemet membrane.Conclusions:Corneal graft repositioning in combination with re-bubbling may represent an effective therapeutic option in keratoconic patients with peripheral thinning in the residual host corneal tissue and subsequent Descemet membrane detachment.