Elisabeth J. Cohen

Results of the Prospective Evaluation of Radial Keratotomy (PERK) Study One Year After Surgery

The Prospective Evaluation of Radial Keratotomy (PERK) study is a nine-center, self-controlled clinical trial of a standardized technique of radial keratotomy in 435 patients who had physiologic myopia with a preoperative refraction between -2.00 and -8.00 diopters. The surgical technique consisted of eight incisions using a diamond micrometer knife with blade length determined by intraoperative ultrasonic pachymetry and the diameter of central clear zone determined by preoperative refraction. At one year after surgery, myopia was reduced in all eyes; 60% were within +/- 1.00 diopter of emmetropia; 30% were undercorrected and 10% were overcorrected by more than 1.00 diopter (range of refraction, -4.25 to +3.38 D). Uncorrected visual acuity was 20/40 or better in 78% of eyes. The operation was most effective in eyes with a refraction between -2.00 and -4.25 diopters. Thirteen percent of patients lost one or two Snellen lines of best corrected visual acuity. However, all but three eyes could be corrected to 20/20. Ten percent of patients increased astigmatism more than 1.00 diopter. Disabling glare was not detected with a clinical glare tester, but three patients reduced their driving at night because of glare. Between six months and one year, the refraction changed by greater than 0.50 diopters in 19% of eyes.

Boston keratoprosthesis outcomes and complications.

Purpose: To evaluate the outcomes of the Boston Keratoprosthesis (KPro) at our institution. Methods: A computerized database retrospectively identified all patients who received a Boston KPro from August 2005 to October 2007. Results: There were 37 patients, 24 (65%) were male. Mean age was 66.3 years (median 69 years, range: 24-93 years; SD = 18.1 years). Mean follow-up was 16 months (range: 6-28 months; SD = 6.0 months). There were 36 type 1 (97%) and 1 type 2 (3%) KPros. The primary indication was failed penetrating keratoplasty in 29 patients (78%)-22 (59%) from multiple failures. Preoperative comorbidities included glaucoma [27 patients (73%)] and limbal stem cell deficiency [13 patients (35%)]. No intraoperative complications occurred. Postoperative complications included retroprosthetic membrane [24 patients (65%)], increased intraocular pressure [14 patients (38%)], glaucoma progression [5 patients (13.5%)], and endophthalmitis [4 patients (11%)-3 who discontinued prophylactic antibiotics secondary to compliance]. Thirty-six KPros (97%) were retained-1 type 2 KPro (3%) in a patient with ocular cicatricial pemphigoid extruded and was replaced. Mean best-corrected visual acuities were counting fingers preoperatively (range: light perception to 20/100) and 20/90 at last follow-up (range: light perception to 20/25). At last follow-up, 31 patients (84%) improved 2 lines or greater-3 patients (8%) had worse vision. Conclusions: Retention rates were excellent, and best-corrected visual acuities improved in the vast majority of patients. Complications can occur and require frequent follow-up to monitor and treat glaucoma progression, endophthalmitis, and inflammation. Patient compliance is of paramount importance. Despite the potential complications, the Boston KPro provides visual improvement in patients with an otherwise poor prognosis.

Comparison of Ciprofloxacin Ophthalmic Solution 0.3% to Fortified Tobramycin-Cefazolin in Treating Bacterial Corneal Ulcers

PURPOSE The purpose of the study is to compare the clinical efficacy and safety of ciprofloxacin ophthalmic solution 0.3% (Ciloxan) with a standard therapy regimen (fortified tobramycin, 1.3%-cefazolin, 5.0%) for treating bacterial corneal ulcers. METHODS This randomized, parallel group, double-masked, multicenter study was conducted in 324 patients at 28 centers in the United States, Europe, and India. Patients were randomized into 2 treatment groups: 160 to ciprofloxacin and 164 to fortified tobramycin-cefazolin. Positive microbiologic cultures were obtained in 188 (58%) of 324 patients. Of these, 176 patients met protocol criteria and were evaluated for treatment efficacy: 82 in the ciprofloxacin group and 94 in the standard therapy group. The dosing schedule for both treatment groups was 1 to 2 drops of the first study medication (ciprofloxacin or fortified tobramycin) every 30 minutes for 6 hours, then hourly for the remainder of day 1; 1 to 2 drops every hour on days 2 and 3; 1 to 2 drops every 2 hours on days 4 and 5, followed by 1 to 2 drops every 4 hours on days 6 to 14. The second medication (ciprofloxacin or cefazolin) was instilled 5 to 15 minutes after the first drug, following the same dosing frequency. Physicians judgment of clinical success, cure rate, changes in ocular sings, and symptoms and the rate of treatment failures were the primary efficacy criteria. RESULTS Topical ciprofloxacin monotherapy is equivalent clinically and statistically to the standard therapy regimen of fortified antibiotics. No statistically significant treatment differences were found between ciprofloxacin (91.5%) and standard therapy (86.2%) in terms of overall clinical efficacy (P = 0.34). Similarly, no differences were noted in resolution of the clinical signs and symptoms (P > 0.08) or the time to cure (P = 0.55). The incidence of treatment failures was less in the ciprofloxacin group (8.5%) compared with the standard therapy group (13.8%). Significantly fewer patients treated with ciprofloxacin reported discomfort than did patients treated with the standard therapy regimen (P = 0.01). CONCLUSION Ciprofloxacin ophthalmic solution 0.3% monotherapy is equivalent clinically and statistically to standard therapy (fortified tobramycin-cefazolin) for the treatment of bacterial corneal ulcers and produces significantly less discomfort.

Recurrence of corneal dystrophy after excimer laser phototherapeutic keratectomy1

BACKGROUND Excimer laser phototherapeutic keratectomy (PTK) can be useful to treat anterior corneal dystrophies both before and after penetrating keratoplasty. OBJECTIVE To evaluate the recurrence of corneal dystrophies after excimer laser PTK. DESIGN Retrospective case series. PARTICIPANTS Fifty excimer laser PTK procedures were performed in 43 eyes of 33 patients with corneal dystrophies. Preoperative diagnoses included Reis-Bücklers dystrophy (13 eyes), granular dystrophy (11 eyes), anterior basement membrane (ABM) dystrophy (11 eyes), lattice dystrophy (7 eyes), and Schnyder crystalline dystrophy (1 eye). INTERVENTION Two excimer lasers (VISX 20/20 model B and VISX Star) were used to perform all PTKs. MAIN OUTCOME MEASURES After PTK, patients were followed on a regular basis with measurement of best-corrected visual acuity and biomicroscopic examination. Evidence of recurrent dystrophy was noted according to specific criteria. RESULTS Follow-up range was from 1.1 to 71.2 months (mean, 19.5 months). Clinically significant recurrent dystrophy occurred in 17 eyes. The ABM dystrophy recurred in the form of recurrent corneal erosions in 5 (42%) of the 12 eyes within 6 to 9 months of PTK. Four of these five eyes had mild erosions, which were treated successfully with topical medications while one eye required an additional PTK for an erosion outside the initial treatment area. Eight (47%) of 17 eyes with Reis-Bücklers dystrophy developed clinically significant recurrence an average of 21.6 months after PTK. Three (23%) of 13 eyes with granular dystrophy were found to have a significant recurrence a mean of 40.3 months after PTK. Only one (14%) of seven eyes with lattice dystrophy developed a significant recurrence at 6 months after PTK. Six eyes with significant recurrence after PTK were retreated successfully with additional PTK. Three eyes later developed recurrence of granular and Reis-Bücklers dystrophy after the second PTK. The probability of recurrence of these dystrophies after PTK was calculated using the Kaplan-Meier survival analysis. CONCLUSION Phototherapeutic keratectomy can restore and preserve useful visual function for a significant period of time in patients with anterior corneal dystrophies. Even though corneal dystrophies are likely to recur eventually after PTK, successful retreatment with PTK is possible.

Indications for Penetrating Keratoplasty and Associated Procedures, 2001–2005

Purpose. To identify current indications and trends in indications for penetrating keratoplasty (PKP) and associated procedures. Methods. Retrospective chart review of all patients who underwent PKP at Wills Eye Institute from January 1, 2001, to December 31, 2005. Results. A total of 1,162 cases were performed in this 5-year period. Leading indications for PKP were pseudophakic corneal edema (PCE) in 330 (28.4%) cases, followed by regraft in 250 (22.0%), keratoconus in 186 (16%), and Fuchs’ endothelial dystrophy in 126 (10.8%) cases. Of the 330 cases of PCE, 232 (70.3%) were associated with posterior chamber intraocular lenses (PCIOLs) and 96 (29.1%) with anterior chamber lenses. In 330 eyes with PCE, the lens was not exchanged in 246 (74.5%) cases and was exchanged in 76 (23%) cases. Seventy of the exchanged lenses were anterior chamber intraocular lenses (ACIOLs) and six lenses were PCIOLs. In cases of ACIOL exchanges, 10 were for scleral sutured IOLs, 18 for PCIOLS, and 42 for another ACIOL. Conclusions. Pseudophakic corneal edema remains the leading indication for PKP at our institution followed by regraft, continuing a trend noted in our previous studies. Although the percentage of cases of PCE associated with PCIOLS increased, fewer lenses were exchanged, perhaps reflecting increased confidence in biocompatibility of newer IOLs. The decrease in overall number of corneal transplants in these 5 years continues a trend noted in our previous study and mirrors the national decline in PKP.

Risk factors in microbial keratitis leading to penetrating keratoplasty

OBJECTIVE To determine the characteristics of infectious corneal ulcers at the time of presentation to the cornea specialist associated with a favorable response to medical therapy versus a poor outcome manifested by the need for penetrating keratoplasty for therapy or visual rehabilitation. DESIGN Retrospective, case-control study. PARTICIPANTS A total of 162 patient records were reviewed, including the study group of 30 patients and the control group of 132 patients. INTERVENTION A retrospective review of all cases of microbial keratitis presenting to the Cornea Service between January 1, 1989 and December 31, 1995 was conducted. The cases were divided into two groups. The study group consisted of patients with microbial keratitis who failed medical therapy and required penetrating keratoplasty. The control group included patients with infectious ulcers who responded to medical therapy alone. MAIN OUTCOME MEASURES The influence of demographics, medical and ocular history, delay in presentation to the primary ophthalmologist or the corneal specialist, topical medications, and contact lens usage were compared. Visual acuity and ulcer characteristics were recorded. The statistical significance was evaluated by the chi-square test for independence and multiple logistic regression. RESULTS Older age (P=0.001), delay in referral to the corneal specialist (P<0.03), and treatment with topical steroids prior to presentation (P<0.0001) were statistically significant factors associated with the need for penetrating keratoplasty. Steroid use and the delay in referral were correlated. A past history of ocular surgery (P=0.01), poor visual acuity at presentation (P<0.001), and ulcer characteristics, including central location (P<0.0001), large size (P<0.0001), presence of perforation or descemetocele (P<0.0001), limbal involvement (P<0.0001), and hypopyon (P=0.05), were all associated with the need for penetrating keratoplasty. CONCLUSIONS Older age, delay in referral to the corneal specialist, topical steroid treatment, past ocular surgery, poor vision at presentation, large size, and central location of the ulcer are risk factors for poor outcome of microbial keratitis, as indicated by the need for penetrating keratoplasty.

Medical and Surgical Treatment of Acanthamoeba Keratitis

We examined seven patients with Acanthamoeba keratitis. All patients had a history of soft contact lens use. Predisposing factors included use of homemade saline, hydrogen peroxide disinfection, a history of improper lens care, and swimming with contact lenses. Currently recommended medical therapy, including topical propamidine isethionate and dibromopropamidine isethionate, miconazole, Neosporin, corticosteroids, and systemic ketoconazole, was used in all patients. Five patients have undergone penetrating keratoplasty for progressive primary Acanthamoeba keratitis (four patients) or recurrent infection (one patient) after maximal medical therapy. Two patients who began medical therapy less than three weeks after the onset of symptoms have done well. Early diagnosis of Acanthamoeba keratitis appears critical for successful medical therapy. Penetrating keratoplasty continues to have a central role in the management of more advanced cases that are unresponsive, or only transiently responsive, to medical therapy.

Corneal Ulcers Associated with Cosmetic Extended Wear Soft Contact Lenses

In 52 patients with a history of using cosmetic extended wear soft contact lenses, corneal ulcers developed requiring admission to Wills Eye Hospital between January 1, 1982, and June 30, 1986. A retrospective study was conducted to determine the contact lens history, clinical presentation, culture and sensitivity results, and final visual acuity of these patients. Pseudomonas organisms were isolated in 75% of culture-positive cases. The final visual acuity was 6/60 or less in 12% of all cases and 25% of the Pseudomonas ulcers. Patients and practitioners must be aware of this vision-threatening problem in patients wearing cosmetic extended wear lenses. The pathogenesis of corneal ulcers in contact lens patients has not been established. There may be an inherent increased risk in the use of extended wear, compared to daily wear, soft contact lenses for cosmetic purposes.

Diagnosis and Management of Acanthamoeba Keratitis

Diagnosis and management of Acanthamoeba chronic ulcerative keratitis is difficult. Two cases of Acanthamoeba keratitis at Wills Eye Hospital were diagnosed within several months of each other during 1983. Corneal transplantation was necessary for diagnosis and therapy in these cases. Another two cases were diagnosed when histopathologic specimens from penetrating keratoplasties done between 1974 and 1983 were reviewed retrospectively. There has been no evidence of recurrent disease in any of our cases during follow-up periods averaging two years (range, 12 to 40 months). The diagnosis of Acanthamoeba keratitis must be considered in cases of chronic progressive corneal ulceration unresponsive to medical therapy.

Descemet's membrane detachment after cataract surgery: management and outcome.

OBJECTIVE To analyze the possible causes of Descemets membrane detachment (DMD) and the treatment and outcome of patients after cataract surgery. DESIGN Retrospective noncomparative interventional case series. PARTICIPANTS Fifteen eyes of 12 patients. METHODS We reviewed clinical data on 15 eyes of 12 patients with nonscrolled DMD after cataract surgery who presented to the Cornea Service at Wills Eye Hospital from 1986 to 2001. Institutional review board/ethics committee approval was obtained. MAIN OUTCOME MEASURES Visual acuity and reattachment of Descemets membrane. RESULTS Cataract procedures involved nine clear-corneal eyes, four limbal incisions, one trabeculectomy/combined phacoemulsification, and one extracapsular cataract extraction. From 1986 to 1990, we had 1 patient; from 1991 to 1995, no patients; and from 1996 to 2001, 11 patients (including all clear-corneal eyes). Of the 15 eyes, 8 resolved with medical treatment alone, with a mean time to resolution of 9.8 weeks. One patient was lost to follow-up while improving on medical treatment, and another required a penetrating keratoplasty (PK) after medical treatment failed. Five eyes received anterior-chamber SF(6) gas injection. Of these eyes, three DMDs resolved, one underwent repeated injection (not improving after 10 weeks), and another required a PK. CONCLUSIONS Referrals for DMD seem to be increasing. This may be explained by the increase in clear-corneal cataract procedures. Medical treatment seems to be adequate in many cases and may be appropriate initial therapy. When needed, SF(6) gas injection may also be successful, but not in all cases.