Intraocular surgery following penetrating keratoplasty: the risks and advantages.

Graft survival has been evaluated for patients who underwent subsequent intraocular surgery (extra-capsular cataract surgery or trabeculectomy) between 1983 and 1989. The patients were different from the majority of keratoplasty patients as evidenced by the indications for keratoplasty; corneal perforation was the indication in 24% of cases. Perforated and inflamed eyes were treated aggressively at the time of the acute event, including emergency keratoplasty and intensive topical steroids. Visco-elastic fluids were routinely used during secondary surgery and topical steroids were administered intensively post-operatively. The incidence of post-operative graft rejection was low (less than 14%). Rejection episodes were diagnosed early, prior to the appearance of a Khodadoust line, and were treated aggressively with intensive topical steroids. Glaucoma which was not controlled by topical therapy was surgically managed by trabeculectomy in the first instance. If this failed, tube drainage was performed and long-term topical steroids were administered. The only risk factor identified was uncontrolled glaucoma, P = 0.1. The probability of graft survival (at five years) was 0.83 after cataract surgery and 0.62 after trabeculectomy, but wide confidence limits indicate the difference is not significant.

The management of post-keratoplasty glaucoma by trabeculectomy.

The results of 35 consecutive trabeculectomies in eyes developing medically uncontrollable glaucoma following penetrating keratoplasty are presented, with a mean follow-up of 3 years from the time of drainage surgery. Five eyes remained phakic until trabeculectomy was performed. Additional medical therapy was necessary to control the intraocular pressure in 32 eyes, which therefore were considered to have failed to be controlled by trabeculectomy and 90% of these failed within 6 months of filtration surgery. Despite additional medical therapy, in 17 eyes, further drainage surgery was required and 90% of this surgery took place within the first 14 months. Adverse prognostic factors were multiple grafts and synechiae closure of the drainage angle.

Effect of osmolarity of artificial tear drops on relief of dry eye symptoms: BJ6 and beyond.

Patients with clinically well defined keratoconjunctivitis sicca (KCS) participated in two trials of hypo-osmolar tear substitutes. The trials were double masked, single crossover studies with computer generated random order allocation and were conducted by postal questionnaire. In the first trial a hypo-osmolar formulation using polyvinylpyrrolidone and hydroxyethyl cellulose was compared with the patients' usual treatment (BJ6 or hypromellose) and found to be inferior, especially in respect of blurring and stickiness caused by higher viscosity. In the second trial hypo-osmolar preparations of BJ6 and hypromellose were compared with their iso-osmolar equivalents and found not to be significantly different in their effects. Hypo-osmolarity alone does not seem to guarantee relief of symptoms in KCS. Other factors including viscosity and colloid osmotic pressure may be more significant.