Faculty Bibliography

PURPOSE/OBJECTIVE:To evaluate changes in the anterior chamber angle after Boston keratoprosthesis (KPro) placement. PATIENTS/METHODS/METHODS:Ten patients were serially imaged with anterior segment optical coherence tomography after Boston KPro surgery. Angles were judged to be open or closed in the horizontal axis. RESULTS:Seven of 10 patients had open angles before KPro placement. Within 4 months, 4 of 7 patients developed angle closure. Contact between the iris and the backplate was seen in 3 of these patients. Two of the 4 eyes demonstrated progressive angle closure. Intraocular pressure was elevated in 3 patients postoperatively due to the obstruction of a glaucoma drainage device tube (1 eye) and angle closure (2 eyes). CONCLUSIONS:After Boston KPro surgery, patients must be carefully monitored for the onset or progression of glaucoma. Progressive angle closure can occur after placement of a Boston KPro and may be seen in conjunction with irido-backplate touch.

PURPOSE OF REVIEW/OBJECTIVE:This review provides an evidence-based comparison of aqueous shunts in common use. RECENT FINDINGS/RESULTS:Aqueous shunts are being used with increasing frequency in the surgical management of glaucoma. Recent retrospective studies and prospective clinical trials have compared the outcomes of different shunt designs. Larger end-plate size is associated with greater intraocular pressure (IOP) reduction, but there may be an upper limit beyond which a further increase in plate surface area does not contribute beneficially to pressure control. The biocompatibility of plate material may also influence shunt efficacy. The flow restrictor of the Ahmed glaucoma valve provides an added level of safety by reducing the risk of postoperative hypotony, but this implant also appears to have a higher incidence of bleb encapsulation. SUMMARY/CONCLUSIONS:Several aqueous shunts are commercially available, and all have been shown to be safe and effective in lowering IOP. Studies comparing aqueous shunts have provided valuable information to assist in surgical decision-making in similar patient groups.

Repositioning a glaucoma drainage device tube from the anterior chamber to the ciliary sulcus or pars plana can be a challenging procedure owing to the difficulty in obtaining tight closure of the original limbal fistula. Failure to achieve watertight and airtight closure of the fistula can result in substantial difficulty in completing other key portions of the surgery and may lead to postoperative hypotony and associated complications. A novel technique using a Tutoplast scleral plug, polyglactin sutures, and, in certain cases, fibrin tissue sealant to close a limbal fistula at the time of glaucoma drainage device tube repositioning is described. This technique can be replicated with ease and provides a tight seal so that other concurrent surgical procedures can safely be completed and postoperative hypotony is avoided.

A rare variant of adenoid cystic carcinoma is the dedifferentiated sarcomatoid form, which has previously been reported in the hard and soft palate, maxillary sinus, submandibular glands, and nasal cavity. The authors report the first case of a dedifferentiated sarcomatoid adenoid cystic carcinoma occurring in the lacrimal gland, that of a 52-year-old man. The patient presented with a 4-month history of diplopia, decreased vision, and right upper eyelid swelling. Radiographic imaging showed a soft tissue mass in the extraconal compartment superolateral to the right eye. The patient subsequently underwent surgical debulking. Histologic examination of the tissue revealed classic cribiform adenoid cystic carcinoma and a sarcomatous component consisting of malignant spindle cells and fusiform cells arranged in whorls. Dedifferentiation is a well-established phenomenon in salivary gland tumors that is associated with aggressive behavior and poor prognosis; however, the exact nature of such dedifferentiated neoplasms remains unclear

The implantation of non-valved aqueous shunting devices in children is often complicated by intraocular pressure elevation in the early postoperative period, during which time the tube is closed with a temporary suture ligature to avoid hypotony. Release of a polyglactin suture ligature using conventional laser lysis is not possible in young children in the clinic setting. The authors describe a minimally invasive technique using a portable green diode (532-nm) laser delivered through a standard endoprobe and a Hoskins laser suture lysis lens to disrupt a polyglactin suture ligature following pars plana aqueous shunt implantation in a young child.