Managing Complications

Glaucoma

The diagnosis and follow-up of glaucoma in Boston KPro-implanted patients are complicated because of the difficulty of measuring intraocular pressure accurately with standard tonometers due to the rigidity of the KPro back plate. An alternative is finger palpation of the sclera, though this method can be subjective and only gives an estimate of the pressure. Additional tests for glaucoma, such as visual fields, fundus photography, and optic nerve imaging, are important for the follow-up.

Autoimmunity

Although a small, but important, group of presumed autoimmune diseases (Stevens–Johnson syndrome, mucous membrane pemphigoid, graft-vs-host disease, atopy, uveitis, etc.) have the least favorable outcomes with KPro surgery, these patients also are the most likely to experience failure with standard corneal allograft surgery. Hence, these patients have the most to gain from KPro implantation. The degree of preoperative chronic inflammation may be predictive of postoperative complications. Implantation of the Boston KPro in patients with autoimmune diseases should be performed only in experienced KPro centers.

Infection

Microbial keratitis is characterized by infection of the donor corneal graft, typically around the KPro stem where uncontrolled infectious organisms can access the inside of the eye. Follow-up is essential to recognize infection before endophthalmitis can set in. Endophthalmitis, usually from Gram-positive bacteria, is almost always consecutive to microbial keratitis. Inflammation should be considered infectious until proven otherwise. Microbial endophthalmitis can occur without signs of infection, and should be referred to a vitreoretinal specialist if suspected. Treatment includes vitreous biopsy, intraocular antibiotics, and an antifungal agent, depending on clinical suspicion.