• penetrating ocular injuries
• blind eyes
• enucleation

We read with great interest the paper by Kilmartin et al¹ in which the authors noted that most of the newly diagnosed cases of sympathetic ophthalmia (SO) in their prospective study occurred in eyes that had sustained multiple injuries, either via trauma or intraocular surgery, and that enucleation following the onset of SO in these eyes was not related to a better visual outcome in the fellow eye. We have recently encountered two cases of ocular trauma in which, with the aforementioned two points in mind, we found it reasonable to consider and offer primary enucleation in an attempt to decrease the risk of SO.

The first case was a 46 year old man who had suffered a previous penetrating injury to his left eye as a child and now presented with a ruptured pre-phthisical globe after striking his left eye with his hand. The patient had previously undergone cataract extraction and trabeculectomy but had no light perception in that eye before the second injury, because of advanced glaucoma. The second patient was a 49 year old man who presented with a large scleral rupture in the left eye after being struck with a metal wrench. Seven years earlier, the patient had sustained a similar injury that had left him with no light perception in that eye. Given that both patients had no light perception in these previously injured eyes, we considered primary enucleation as a way to minimise the risk of SO. Both patients declined primary enucleation and have not developed any signs of ocular inflammation more than 6 months following repair of their second penetrating ocular injuries.

Sympathetic ophthalmia, a rare bilateral granulomatous panuveitis, presumably arises following penetrating ocular injury and surgery as a result of lymphatic exposure to a previously sequestered antigen.² The risk of SO following a penetrating ocular injury ranges from 0.1% to 0.3%.^3–5 Although the risk of SO with multiple penetrating injuries has not been defined, increased antigen release with repeat uveal exposure probably carries an additive risk. This is supported by the finding that most of the newly diagnosed cases of SO in the study by Kilmartin et al¹ had experienced multiple penetrating ocular events.

In addition, as Kilmartin et al¹ have shown, once SO develops, secondary enucleation of the exciting eye to reduce inflammation in the sympathising eye does not necessarily lead to a better visual outcome or to a reduced need for anti-inflammatory treatment. Secondary enucleation is often performed within 14 days of injury as protection against SO for repaired ruptured globes that demonstrate no potential for functional vision.⁶ Unfortunately, the time frame necessary to perform prophylactic secondary enucleation remains uncertain, as SO has been reported with secondary enucleation performed as early as 5 days following a penetrating ocular injury.⁷ The pre-existing lack of vision in previously injured eyes, however, changes the context in which a subsequent penetrating ocular injury is managed. In this setting, repairing the injury in order to assess for visual potential is futile, and primary enucleation may offer the best prophylaxis against SO.

In many instances, individuals who sustain multiple episodes of trauma either have poor access to health care or are non-compliant with prescribed drugs. Should SO develop in such patients, delayed presentation to an ophthalmologist may lead to an unfavourable outcome, as improved results have been shown with prompt and aggressive anti-inflammatory therapy.^1,8 Even patients who present early in the course of the disease may be committed to a lifetime of immunosuppressive therapy in order to salvage vision in their only seeing eye.

While primary enucleation is not typically recommended in open globe injuries, it may have a role in select cases of penetrating ocular injuries, such as those involving previously injured blind eyes. In these situations, the ophthalmologist and the patient must carefully assess and discuss the potentially increased risk of SO associated with preserving a disorganised, possibly painful, sightless eye.