Abstract
Abstract: :
Purpose: Several studies have sought to identify if high dose inhaled steroids cause suppression of the hypothalamic-pituitary-adrenal (HPA) axis, though as yet no research has studied patients receiving topical steroids for ocular pathologies since the 1970s. These studies only looked at short-term steroid use and in very few patients. To prevent penetrating keratoplasty rejection long-term topical steroid is often necessary. The purpose of this pilot study is to identify if there is a link between the topical use of ophthalmic corticosteroid preparations and adrenal suppression. Method: Twenty patients were recruited from the corneal transplantation service on a specialised investigation unit. They had been on daily topical steroids following penetrating keratoplasty, either prednisolone 1% or 0.5% for greater than 6 months. There was no other history of steroid use. All patients had measurements of serum cortisol followed by a standard short synacthen test (SST). A 24hr urine collection also determined urine-free cortisol (UFC) excretion. The widely accepted standard of HPA axis suppression defined as a base-line cortisol value of <190nmol/L, a 60-minute cortisol level of < 550 nmol/L (under the SST) and a UFC<80 nmol/24hr was used. Results: The twenty patients consisted of 7 male and 13 female with a mean age of 62 (range16-86). Mean base-line cortisol value was 412.35 (± 116.87), mean 60-minute cortisol 801.80 (± 136.97) and mean urine-free cortisol 236.42 (± 208.22). All patients were found to have adequate adrenal function based on the above three tests; one of the patients had a low urine free cortisol excretion but had no HPA suppression on standard SST. No clear relationship was identified between HPA suppression and dose. Conclusion: No patients have adrenal suppression according to the above definition. This small study has yielded positive up-to-date results for the use of long-term low dose topical steroids in corneal transplantation. Future work will study the low dose adrenocorticotropin test that may reveal mild adrenal insufficiency, which is not detected by the standard SST. Commercial Relationships: none.
Keywords: 377 corticosteroids • 607 transplantation • 369 cornea: clinical science