A REVIEW OF 72 CONSECUTIVE CASES OF ACANTHAMOEBA-KERATITIS, 1984-1992

A review of consecutive cases of Acanthamoeba keratitis presenting sin ce 1984 was undertaken in order to assess prognostic factors, the succ ess of culture procedures and the outcome of medical and surgical mana gement, with reference to current clinical practice. Seventy-two conse cutive cases (77 eyes) of Acanthamoeba keratitis have been managed. Si xty-four patients were contact lens wearers, 28 of these wearing dispo sable lenses. Superficial corneal involvement and perineural infiltrat es mere common in those diagnosed less than a month after first sympto ms, designated `early' presentation. Ring infiltrates and ulceration w ith stromal lysis characterised those presenting at 1-2 months (`inter mediate') or after 2 months (`late'); these groups also progressed mor e frequently to hypopyon, scleritis, glaucoma and cataract formation. Positive corneal cultures were obtained in 10 of 14 (71%) intermediate and 17 of 23 (74%) late cases; early cases underwent epithelial biops y but formal trephine biopsy was not usually justified (1 of 35 cases) and only 19 of 35 (54%) were tissue-positive. Microbial coisolates we re obtained from 20 corneas. Thirty-four penetrating keratoplasties we re performed in 23 eyes, 21 whilst inflamed and 13 when quiet. Of 13 f ailures in inflamed eyes, 9 were due to recurrence of Acanthamoeba inf ection. Medical cure is known to have been achieved in 64 of 73 (88%) eyes, 4 of the original 77 having been lost to follow-up abroad. Fifty -eight of 73 eyes (79%) achieved a final visual acuity of 6/12, and of the culture-positive cases, 32 of 46 (70%) achieved 6/12. Since 1984 an effective biguanide-propamidine treatment combination has been intr oduced, cases have been diagnosed increasingly early and consequently the time taken for medical cure has decreased. The prognosis of this p otentially blinding keratitis has improved due to heightened clinical suspicion resulting in early diagnosis, a rigorous scheme of investiga tion and proven management strategies.