Linda A. Ficker

A review of 72 consecutive cases of Acanthamoeba keratitis, 1984–1992

A review of consecutive cases of Acanthamoeba keratitis presenting since 1984 was undertaken in order to assess prognostic factors, the success of culture procedures and the outcome of medical and surgical management, with reference to current clinical practice. Seventy-two consecutive cases (77 eyes) of Acanthamoeba keratitis have been managed. Sixty-four patients were contact lens wearers, 28 of these wearing disposable lenses. Superficial corneal involvement and perineural infiltrates were common in those diagnosed less than a month after first symptoms, designated ‘early’ presentation. Ring infiltrates and ulceration with stromal lysis characterised those presenting at 1-2 months (‘intermediate’) or after 2 months (‘late’); these groups also progressed more 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 biopsy but formal trephine biopsy was not usually justified (1 of 35 cases) and only 19 of 35 (54%) were tissue-positive. Microbial co-isolates were obtained from 20 corneas. Thirty-four penetrating keratoplasties were performed in 23 eyes, 21 whilst inflamed and 13 when quiet. Of 13 failures in inflamed eyes, 9 were due to recurrence of Acanthamoeba infection. 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 introduced, cases have been diagnosed increasingly early and consequently the time taken for medical cure has decreased. The prognosis of this potentially blinding keratitis has improved due to heightened clinical suspicion resulting in early diagnosis, a rigorous scheme of investigation and proven management strategies.

The success of penetrating keratoplasty for keratoconus

We report the results, over a 20 year period up to 1989, of 201 penetrating keratoplasties in 198 eyes of 158 patients. The five year graft survival was 97%. A corrected visual acuity of 6/12 or better was attained by 91%. The mean spherical equivalent refraction on removal of sutures was -2.68 Ds and the mean cylindrical correction was —5.56 Ds. The cumulative time to dispensing final refractive correction was 38 months for 90% of patients. Rejection episodes occurred in 20% of grafts and were associated with loosening of sutures and bilateral grafts. Atopic patients (28%) were not at greater risk from rejection.Graft refractive surgery was undertaken in 18% and, of these, 55% achieved 6/12 vision or better with an refractive correction which could be dispensed and tolerated within 6 months.

Acanthamoeba keratitis. The value of early diagnosis.

BACKGROUND The treatment of Acanthamoeba keratitis has been increasingly successful as diagnoses are made earlier. The authors investigated features of the disease and prognosis in a consecutive series of 15 patients who were treated within 1 month of initial symptoms. METHODS A database of patients with Acanthamoeba infection presenting between March 1984 and March 1992 was analyzed. The recognition, presenting features, culture methods, results, and treatment of the early cases were reviewed to determine the reasons for a good outcome. RESULTS Recognition depended on perineural infiltrates (11/15), uveitis (10/15), limbitis (14/15), and infiltrated epithelium; 6 of 15 patients had epithelial defects, but only 3 of 15 had ring infiltrates or ulcers. Epithelial biopsy was culture-positive in 12 of 15 patients. Most (11/15) patients needed only two anti-amebal drugs. One patient only required penetrating keratoplasty for uncontrolled disease. The final visual acuity was at least 6/12 in all patients who had been treated within 1 month of first symptoms, whereas only 17 (53%) of 32 eyes of patients who presented after 1 month achieved a visual acuity of 6/12. CONCLUSIONS Subtle diagnostic signs, supported by comprehensive microbiologic investigation, justify the immediate instigation of specific antiamebal therapy. Treatment within 1 month of onset results in a lower morbidity and a good visual outcome.

Conjunctival autografting in the surgical management of pterygium.

In a retrospective survey of 117 operations for primary or recurrent pterygium, conjunctival autografting was compared with both excision without conjunctival closure (‘bare sciera excision’) and excision with complete conjunctival closure. The probability of corneal recurrence at 36 months after surgery was determined by survival curve analysis. In previously unoperated cases conjunctival autografting (n = 15) resulted in a 14% probability of recurrence, compared with 70% for bare sciera excision (n = 50) and 69% for excision with complete conjunctival closure (n = 20). In previously operated cases conjunctival autografting (n = 17) resulted in a 7% probability of recurrence, compared with 82% for bare sciera excision (n = 15). Hazard ratio analysis confirmed the statistical significance of these results at the 95% confidence level. Conjunctival autografting was more likely to produce an improvement in visual acuity than other forms of surgery.

Risk factors for the development of postkeratoplasty glaucoma.

From a database of 1,122 penetrating keratoplasties performed under the care of the surgeons of the Corneal Clinic, Moorfields Eye Hospital (London, U.K.), 153 (14%) were identified as being complicated by postkeratoplasty glaucoma. The relative risk for its development varied with the indication for keratoplasty. Keratoconus had the lowest incidence along with some dystrophies, such as macular or granular dystrophy, and these were taken as the baseline for comparison. Anterior chamber dysgenesis syndromes had the highest risk among the indications for keratoplasty. Combined cataract or lens implant surgery was also found to be a risk factor, with anterior vitrectomy, anterior segment revision, and anterior chamber lens implant removal representing a greater risk than extracapsular extraction and posterior chamber lens implantation. Postkeratoplasty glaucoma was also strongly associated with peripheral anterior synechiae formation seen after keratoplasty.

Granular Corneal Dystrophy: Visual Results and Pattern of Recurrence after Lamellar or Penetrating Keratoplasty

BACKGROUND Granular corneal dystrophy is a rare indication for corneal transplantation. Both penetrating and lamellar keratoplasty have been recommended, but because granular corneal dystrophy is known to recur within the donor material and multiple grafts may be necessary, the best surgical option has not been clearly established. The cellular cause of the dystrophy is unknown and the authors hypothesized that the rate and pattern of recurrence within lamellar and penetrating grafts might give clues to its etiology. METHODS The authors compared the visual outcome, rate, and pattern of recurrence after 20 penetrating keratoplasties and 11 lamellar keratoplasties for granular corneal dystrophy. RESULTS Penetrating keratoplasty and lamellar keratoplasty have a good visual outcome in granular corneal dystrophy. Visual acuities after both procedures were not statistically different. Recurrence of the dystrophy within the graft material was almost universal within 4 years. It first appeared centrally and superficially, occasionally adopting a vortex pattern suggesting epithelial involvement. The recurrence-free interval was independent of size and type of graft performed. CONCLUSION The authors recommend lamellar keratoplasty as a primary procedure in managing visually disabling granular corneal dystrophy if the deposits are limited to the superficial cornea. This is particularly applicable in younger patients in whom multiple procedures may be necessary over a lifetime due to recurrence of the dystrophy, and the lower morbidity rate associated with lamellar keratoplasty becomes appreciable. Although granular corneal dystrophy generally is classified as a stromal dystrophy, the pattern of recurrence is more consistent with an epithelial or tear-borne abnormality than a disease of the stromal keratocyte.

Prognosis for Keratoplasty in Acanthamoeba Keratitis

STUDY Penetrating keratoplasty (PK) was undertaken between 1985-1991 at Moorfields Eye Hospital in 13 eyes (19 PKs) of 11 patients who developed Acanthamoeba keratitis. Infection was ultimately controlled in all cases. Retrospective analysis was undertaken to establish risk factors for PK. Six eyes were quiet and 7 had uncontrolled infection at the time of keratoplasty. The outcome for these was compared. COMPLICATIONS Complications included cataract in 50% of quiet eyes and 100% of inflamed eyes. Intumescent cataract resulted in glaucoma requiring drainage surgery in 4 eyes. Graft rejection episodes occurred in 50% of quiet eyes, but were treated aggressively and did not cause graft failure. RESULTS Graft survival was excellent for quiet eyes, but was compromised by recurrent infection in inflamed eyes and 6 patients were regrafted. Survival compared poorly with grafting for active herpetic or bacterial keratitis, indicating that early diagnosis and treatment are essential for adequate control of this disease.

The Management of Corneal Perforations Associated with Rheumatoid Arthritis: An Analysis of 32 Eyes

BACKGROUND Sterile corneal ulceration is a rare complication of rheumatoid arthritis and may lead to corneal perforation. Surgical management for visual restoration frequently is unsuccessful. The authors analyze the factors that may determine the failure of corneal surgery in perforations associated with rheumatoid arthritis. METHOD The management of 29 patients with rheumatoid arthritis with corneal perforations requiring surgical intervention was reviewed. The corneal lesions were classified either as necrotizing keratitis (n = 20) or as ulcers secondary to surface disease (n = 12), depending on the most evident primary pathology. The outcome of different methods for primary repair (i.e., application of tissue adhesive, lamellar graft, or penetrating keratoplasty) and graft survival in penetrating keratoplasties were analyzed. RESULTS Fifty-seven corneal procedures were performed in 32 eyes. Primary repair was successful (i.e., no further corneal surgery within 6 months was required) in five eyes (25%) with necrotizing keratitis and in eight eyes (67%) with perforations secondary to surface disease. The application of tissue adhesive, when planned as long-term treatment, was unsuccessful in all five eyes. Immunosuppression significantly improved the survival of first penetrating grafts (42% graft survival after 1 year versus 11% without immunosuppression, P = 0.02). Of 25 graft failures, 20 (80%) were caused by recurrent melts up to 6 months after penetrating keratoplasty. Ocular surface infection was responsible for failure in six of ten grafts after that time. CONCLUSION Complications of corneal surgery in rheumatoid corneal perforations are frequent. The type of surgical procedure, the predominant pathogenic mechanism, and the perioperative immune status influence the outcome. The control of corneal melting and the prevention of surface infection are critical for graft survival.

Refractive Surgery for Graft-induced Astigmatism after Penetrating Keratoplasty for Keratoconus

Of a series of 201 corneal transplants for keratoconus over a 20-year period, 42 grafts (39 eyes of 38 patients) required further surgery because of intolerable astigmatism (range, -3 diopters [D] to -18 D; mean, 8.9 D). Relaxing incisions, compressive resuturing, and augmented relaxing incisions were the techniques used. All procedures resulted in a similar mean reduction in cylinder -3.6 to 5 D, but the outcome with augmented relaxing incisions was less predictable. Six grafts required two or more procedures for a satisfactory outcome. All patients had corrected visual acuity of 20/30 or better after surgery, and 75% had visual acuity of 20/20 or better. The cumulative time until 90% of the grafts had useful vision was 32 months after refractive surgery. Relaxing incisions offer the prospect of more rapid visual rehabilitation than compressive resuturing.

Astigmatic keratotomy for post-keratoplasty astigmatism

PURPOSE: To assess astigmatic keratotomy as a means of managing post‐keratoplasty astigmatism in the era of excimer laser refractive surgery. SETTING: Moorfields Eye Hospital, London, England. METHODS: Fifty paired arcuate keratotomies were performed with refractive and topographic guidance. Refraction, uncorrected visual acuity, best corrected visual acuity, and visual acuity with the patients preferred correction were measured before and after surgery. RESULTS: The median follow‐up was 34 months. The mean cylinder was 9.13 diopters (D) preoperatively and 4.85 D postoperatively. The mean spherical equivalent refraction was −4.21 D preoperatively and −4.26 D postoperatively. The amount of cylinder reduction was correlated with the amount of pre‐existing cylinder (P<.001). Thirty eyes (60%) gained and 1 eye (2%) lost Snellen acuity with preferred correction. In the remaining 19 eyes (38%), there was no change in acuity with preferred correction. The mean change in visual acuity with preferred correction was a gain of 1.5 Snellen lines. Three patients intolerant of spectacles or contact lenses before surgery became tolerant. Ten patients (20%) previously unsuitable for laser in situ keratomileusis (LASIK) because of high cylindrical error went on to have LASIK. CONCLUSIONS: Astigmatic keratotomy remains a useful, safe, relatively simple surgical procedure for treating post‐keratoplasty astigmatism. Reduction in cylinder was correlated with pre‐existing cylinder. Vision with preferred correction was improved in 60% of cases. High astigmatism reduced to a level at which more definitive refractive surgery such as LASIK became feasible.