Socket surgery issues

While most prosthetic eyes are cosmetically satisfactory and generally well tolerated, complicated sockets, when they occur, present a real challenge to the ocular prosthetist and the oculo-plastic surgeon, according to Geoffrey E Rose FRCS FRCOphth. In a keynote address on the problems of socket surgery given at the European Society of Ophthalmology (SOE) Congress in Barcelona, Prof Rose stressed the role of patient education in ensuring the long-term viability of the implant. “We need to carefully manage patient expectations and emphasise to them that this is not just a once-off procedure but will require ongoing care and monitoring over the course of their lifetime. They need to know the complications and limitations of the prosthesis and accept that all sockets have some discharge of mucus and that the movements of an artificial eye can never be completely normal. The good news, however, is that a socket with good volume and a stable artificial eye can serve them a long time indeed before further surgical intervention may be required,” he said. Prof Rose, Moorfields Eye Hospital, London, United Kingdom, said that socket problems can be broadly divided into three groups: poor appearance sockets, unstable artificial eyes and troublesome sockets. “There is often an overlap between these categories, with patients often experiencing problems in several of the groups. Furthermore, a structural problem will frequently result in all three of the categories being involved,” he said. Characteristic features associated with poor appearance sockets include misaligned pupils, deep upper sulcus, lower lid contour, crease and displacement, poor movement, and upper eyelid ptosis. Unstable prostheses may occur for a variety of reasons, including poor fit due to orbital fat atrophy and implant migration resulting in recession of the prosthesis with the corresponding narrowing of the palpebral fissure. Issues with troublesome sockets include chronic discharge, itching and burning, painful blinking, lashes adherent to prosthesis and socket ache, noted Prof Rose. One of the most common causes of poor appearance sockets is post-enucleation socket syndrome (PESS). Several pathophysiological mechanisms have been proposed to account for the symptoms of PESS, including enophthalmos, sulcus deformity, upper and lower lid malposition and backward tilt of the prosthesis, said Prof Rose. “Unfortunately, most ocularists will try to compensate for inadequate intraorbital tissues by making a very large, oversized artificial eye, which generates its own range of problems, such as elephant-eye syndrome,” he said. Over time, the heavy, oversized prosthesis will result in poor contouring and a displaced lower lid. Problems with elephant eye syndrome arise from a disparity between the prosthetic surface area and the area of socket lining, said Prof Rose. “The bigger the prosthesis the worse will be any foreign body reaction and biofilm-induced inflammation,” he said. Prevention is the best cure for PESS or elephant eye syndrome advised Prof Rose. “We can achieve this by implanting an adequate size prosthesis, which nearly always means a 22mm orbital implant, unless there is inadequate tissue cover,” he said. In cases of poor movement of the prosthesis, he advised that the ocularist should not try to support the upper lid with the artificial eye unless there is a neurological or structural reason for doing so. “He or she should make a prosthesis centred relative to the lower lid and then levator surgery can be performed later,” he said. For scarred sockets with lining deficiency, Prof Rose suggested relining the socket after volume enhancement. “We should reline dry sockets with skin and moist sockets with mucosa and never mix the two lining types,” he said. For chronic discharge problems, the goal should be to reduce the bacterial load within the socket. Having a properly moulded implant helps and cleaning and polishing regimes are important to reduce biofilm on the prosthesis, said Prof Rose. Blepharitis and atopy should be treated and other sources of organisms such as blocked lacrimal drainage and canaliculitis should be tackled. The inflammatory response may also be reduced with topical steroids, he added. Geoffrey E Rose: geoff.rose@moorfields.nhs.uk

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