Tale of a double anterior chamber post optical penetrating keratoplasty

A 28-year-old male presented with poor vision in both eyes since childhood. His siblings also had poor vision since childhood. There was no history of trauma or prior eye surgery. On examination, the visual acuity was hand movements close to face in the right eye and finger counting close to the face in the left eye, with accurate projection of rays. Slit-lamp examination revealed diffuse corneal edema extending from limbus to limbus in both eyes, with central golden-yellow deposits overlying the edematous cornea. The posterior segment ultrasound scan was normal in both eyes, with an axial length of approximately 21 mm. A diagnosis of congenital hereditary endothelial dystrophy (CHED) with secondary spheroidal degeneration in both eyes was established, and the patient was planned for optical penetrating keratoplasty (OPK) in the left eye. After obtaining informed consent, OPK was performed in the left eye following the standard surgical technique. On postoperative day one, the patient had poor visual improvement, with an unaided visual acuity of 1/60 in the left eye. Slit-lamp examination revealed a corneal graft in place with good graft-host apposition and no epithelial defect. However, the graft was edematous, and a double anterior chamber with a membrane in the anterior chamber was observed. What would you do next? Increase the frequency of topical steroids and observe. Attach Descemet’s membrane with intracameral gas. Perform trypan blue-assisted Descemet’s membrane removal and step-up topical steroids. Replace the corneal graft as early as possible. Findings Fig. 1a shows a slit lamp image of the left eye with diffuse corneal edema and a double anterior chamber with a membrane in the anterior chamber, the extent of which is not visible due to the edema at the graft-host junction and the opaque host peripheral corneal rim. Fig. 1b shows the anterior segment optical coherence tomography (AS-OCT) of the left eye with a thick, hyper-reflective wavy membrane in the anterior chamber extending beyond the graft-host junction. Fig. 1c and d show the slit-lamp and AS-OCT images, respectively, after trypan blue and intraoperative OCT-assisted removal of the retained host Descemet’s membrane.Figure 1: (a) Slit-lamp image of the left eye showing diffuse corneal graft edema and a double anterior chamber with a membrane in the anterior chamber. The extent of the membrane is not visible due to edema at the graft-host junction and the host corneal rim. (b) AS-OCT of the left eye displaying a thick, hype-reflective wavy membrane in the anterior chamber extending beyond the graft-host junction. (c and d) show the slit-lamp and AS-OCT images, respectively, after trypan blue and intraoperative OCT-assisted removal of the retained host Descemet’s membrane.Diagnosis Bilateral CHED with spheroidal degeneration with left eye operated for optical penetrating keratoplasty with retained Descemet’s membrane. Correct answer Trypan blue-assisted Descemet’s membrane removal and step-up topical steroids. Discussion Detachment of Descemet’s membrane from the donor cornea is a rare complication in the early postoperative period after OPK.[1] Intraoperative manipulations such as viscoelastic injection, vigorous anterior chamber wash, and air injection can lead to detachment of the donor Descemet’s membrane. Postoperatively, this can result in the formation of a double anterior chamber and failure of the corneal graft.[1] Conditions such as CHED and bullous keratopathy are prone to retention of the host Descemet’s membrane during trephination and corneal button removal.[2] This can also present as a double anterior chamber. Such cases can create a diagnostic dilemma, potentially leading to inadvertent interventions such as intracameral air or gas injection, which may increase inflammation, cause endothelial cell loss or infections, and ultimately result in graft rejection or failure. AS-OCT is a valuable tool in such cases to ascertain the source of the Descemet’s membrane.[3] Scanning the central cornea may be inconclusive, especially when the membrane is thin or partially detached. However, scans taken at the graft-host junction can clearly delineate the extend of the membrane. In cases of retained host Descemet’s membrane, the membrane will cross the graft-host junction, whereas this will not occur with a detached donor graft Descemet’s membrane.[3] This can be managed by various methods, of which trypan blue-assisted surgical removal with or without intraoperative OCT is the widely accepted technique.[4] During descemetorhexis, the rhexis should be initiated peripheral to the graft-host junction to prevent inadvertent damage to the donor graft Descemet’s membrane, targeting only the retained host Descemet’s membrane. Nd YAG laser-assisted membranectomy is a minimally invasive procedure that can improve vision in cases where an opaque membrane is detected in the late postoperative period.[5] In our case, AS-OCT was the key diagnostic tool that guided our approach. The patient promptly underwent removal of the host Descemet’s membrane with the assistance of trypan blue dye and intraoperative OCT without delay. The subsequent increase in the topical steroid regimen resulted in the resolution of graft edema and an improvement in vision to 6/24. At the 2-year follow-up, all sutures had been removed; the graft clarity was graded as 4+, with good endothelial cell density and a corrected distance visual acuity of 6/18. Financial support and sponsorship: Nil. Conflicts of interest: There are no conflicts of interest.