Ophthalmologists are well versed in the complications of corneal transplants, but how well do they know the ocular complications of lung transplants? Ocular complications related to lung transplants can indicate serious health problems. Eye complications in lung transplant patients have even been linked to increased mortality. "Herein, we report six cases of infectious ocular complications among 46 patients examined at Cole Eye Institute after unilateral or bilateral lung transplant at the Cleveland Clinic," wrote lead study author Ahmad B. Tarabishy, M.D., Cole Eye Institute, Cleveland Clinic, Cleveland. "Five of six patients died within a few months of presentation."
That's likely no coincidence, according to the study, published online in the British Journal of Ophthalmology in December 2010. "We suspect that infectious ocular complications may be an indication of an excessive level of immunosuppression that may lead to additional infection, sepsis and even death," Dr. Tarabishy reported.
A minority of patients that undergo lung transplantation end up with eye infections. In this series, 545 patients received lung transplants, 46 (8.4%) had eye exams afterward, and of those, six (13%) had ocular infections. Yet five of six patients with ocular infectious complications died within 6 months of eye evaluation. "One patient with P boydii infection died from disseminated infection, while three other patients died of causes other than the infection related to their infectious ocular complication," Dr. Tarabishy reported. "Laboratory evaluation of patients with infectious complications indicated that their immune status was worse than those without infectious complications."
Already patients with lung transplants "have among the highest mortalities of solid organ transplant patients," Dr. Tarabishy acknowledged. Interestingly, although the lung transplant was first performed in 1963, the 5-year mortality rate still stands at 50%, according to Dr. Tarabishy. Additionally, eye infection seems to exacerbate things. "The mean white blood cell count in patients with non-infectious and infectious findings was 7.36 and 5.98 K/ml, respectively," Dr. Tarabishy noted. "The average absolute neutrophil count was 5.19 and 4.64 K/ml, respectively. The average absolute lymphocyte count was 1.49 and 0.74 K/ml, respectively."
P. boydii is a particularly vicious organism, Dr. Tarabishy noted. Apart from causing endophthalmitis, P. boydii infection in eight patients with disseminated disease after solid organ transplant led to 100% mortality. Increased immunosuppression causes other problems."Squamous cell carcinoma occurred in two patients, involving the eyelid in one patient and the conjunctiva in another," Dr. Tarabishy reported. "The increased incidence of squamous cell carcinoma in solid organ transplant and other immunosuppressed populations is well recognised."
A surprising new finding involves the appearance of a full-thickness macular hole and retinal detachment in two patients with pulmonary arterial hypertension.
"We think a combination of factors may have caused a serous macular detachment or severe cystoids oedema that led to the formation of a macular hole, turning the serous retinal detachment into a rhegmatogenous retinal detachment," Dr. Tarabishy reported. "Haemodynamic changes at the time of surgery, which involves placement on cardiopulmonary bypass, may have led to an acute rise in systemic venous pressure, possibly causing an exacerbation of the serous effusion. Moreover, the surgical repair of these cases did not follow the usual course, and all patients had recurrent proliferative vitreoretinopathy and multiple surgeries."
Unfortunately, outcomes for lung transplant patients with ocular complications appear grim. "Routine preoperative and postoperative eye examinations for organ transplant patients have been proposed by some authors based on the occurrence of infectious complications after transplantation," Dr. Tarabishy noted, but added, "Based on these data, it is unclear whether routine ophthalmological examination in this population is beneficial."
Nevertheless, for all patients who undergo lung transplantation, vigilant monitoring is warranted. "At the Cleveland Clinic, patients are immediately started on an immunosuppressive regimen after transplantation consisting of tacrolimus, an antimetabolite such as mycophenolate mofetil or azathioprine, and high-dose corticosteroids," Dr. Tarabishy noted. "The post-transplant protocol requires that patients are never off corticosteroids at any time, and most patients are maintained on 5 mg once a day at the lowest dose, and that serum tacrolimus levels are maintained between 5 and 20 ng/ml. Patients are followed closely by the transplantation centre at the Cleveland Clinic and undergo an extensive battery of surveillance testing for rejection and immunosuppressive complications."
Bjorn Johansson, M.D., Linkoping University Hospital, Linkoping, Sweden, said that it's not "unreasonable" to find a connection between eye infection in lung transplant patients and increased mortality.
"We do quite a lot of bilateral cataract surgery," Dr. Johansson said. "If a patient is on an immunosuppressant medication, like steroids or cytotoxic agents, we do one eye at a time because we don't want to risk bilateral infection." In other words, Dr. Johansson draws a connection between immunosuppressant medications—which are mainstays of lung transplantation therapy—and eye infection and increased mortality. "I would say it's probably not the lung disease itself [contributing to increased mortality] but more likely the immunosuppressant," Dr. Johansson said. Notably, resumed causes of death in the patients in this study included septic shock and various infections. Only one patient died as a result of chronic lung rejection.
Editors' note: Dr. Johansson has no financial interests related to his comments. Dr. Tarabishy has no financial interests related to this study.