Faculty Bibliography

The purpose of the Committee on Ophthalmic Procedures Assessment is to evaluate on a scientific basis new and existing ophthalmic tests, devices, and procedures for their safety, efficacy, clinical effectiveness, and appropriate uses. Evaluations include examination of available literature, epidemiological analyses when appropriate, and compilation of opinions from recognized experts and other interested parties. After appropriate review by all contributors, including legal counsel, assessments are submitted to the Academy's Board of Trustees for consideration as official Academy policy. $$:

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-Bucklers 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-Bucklers 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-Bucklers 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

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

OBJECTIVE: To determine the efficacy of systemic acyclovir in decreasing complications and improving the outcome of penetrating keratoplasty for herpes simplex virus (HSV) keratitis. METHODS: Retrospective study of 53 primary penetrating keratoplasties for HSV keratitis at an eye hospital from January 1, 1989, through December 31, 1996. Medical records were analyzed for history of HSV keratitis, preoperative neovascularization, and disease activity. Postoperative use of acyclovir, recurrence of HSV keratitis, rejection, uveitis or edema, and graft failure were evaluated. RESULTS: Twenty-four patients (mean +/- SD follow-up, 44.7 +/- 32.6 months) received no acyclovir and were compared with 20 patients, (mean +/- SD follow-up, 28.8 +/- 16.7 months), who received 400 mg acyclovir twice a day for at least 1 year. No patient in the acyclovir group had a recurrence of dendritic keratitis in the first year compared with 5 (21%) of the patients who did not receive acyclovir (P = .03). No patient had graft failure in the acyclovir group compared with 4 (17%) in the group without acyclovir after 1 year of follow-up (P = .06). CONCLUSION: Postoperative systemic acyclovir therapy after penetrating keratoplasty for HSV keratitis is associated with a reduced rate of recurrent HSV dendritic keratitis and possible graft failure at 1 year of follow-up

BACKGROUND AND OBJECTIVE: To evaluate potential triggering factors contributing to corneal graft rejection. PATIENTS AND METHODS: A prospective, case control study was conducted over a five month period. All patients presenting with new onset corneal graft rejection were enrolled into the study group. Two patients with clear grafts who presented shortly after each enrolled study group patient served as controls. Groups were matched for age, preoperative diagnosis, and number of previous keratoplasties. Participating patients and examining ophthalmologists filled out questionnaires regarding infectious, environmental and immunologic exposures. RESULTS: 66 patients were enrolled into the study, of which 22 had new rejection episodes. The most prevalent diagnoses were keratoconus (36.6%) and herpes simplex keratitis (22.7%). Anterior chamber reaction (77.3%) and keratic precipitates (68.2%) were the most common signs of graft rejection. A history of prior rejection episodes was significantly more frequent in the study group population (p < 0.001). Factors such as sun exposure, stress, smoking and travel were more prevalent in the rejection group but not statistically significant. The history of recent vaccinations and allergic reactions were equally prevalent in both groups. CONCLUSIONS: The new onset of corneal graft rejection was highly associated with a prior history of graft rejection episodes (p < 0.001). Other analyzed factors were not significant triggering factors for rejection in this small series

OBJECTIVE: To show the utility of ultrasound biomicroscopy (UBM) in imaging small ocular foreign bodies of the anterior segment. DESIGN: Retrospective case series. PARTICIPANTS: Twelve eyes of 12 consecutive patients evaluated in the emergency department or referred to specialty services at 1 institution between August 1994 and November 1997 were examined. INTERVENTION: Ocular ultrasound biomicroscopy was performed. MAIN OUTCOME MEASURES: Detection and localization of an ocular foreign body were measured. RESULTS: An intraocular or superficial foreign body was detected by UBM in 9 (75%) of 12 eyes. The foreign body was classified as corneal in two eyes, subconjunctival in two, intrascleral in three, and intraocular in two eyes. The foreign body was not visible by ophthalmic physical examination in seven of the nine eyes with a confirmed ocular foreign body. In the remaining two eyes, UBM was used to determine the depth of a visible foreign body. In three of the eyes with a confirmed foreign body, computed tomography and/or contact B-scan ultrasonography was obtained and failed to show a foreign body. Six of the foreign bodies were nonmetallic. CONCLUSIONS: Clinical detection of ocular foreign bodies after trauma can be hindered by small size, haziness of the optical media, poor patient cooperation, or hidden location. Ultrasound biomicroscopy is a valuable adjunct in the evaluation of suspected ocular foreign bodies, especially in cases involving small, nonmetallic objects

PURPOSE: To identify factors associated with the development of hydrops and affecting its clinical outcome. METHODS: Chart review of all patients with acute hydrops seen by a referral cornea service during a 2.5-year period between June 1996 and December 1998. RESULTS: Twenty-one patients (22 eyes) with acute hydrops were seen. Nineteen patients had keratoconus, 2 had pellucid marginal degeneration, and 1 had keratoglobus. Twenty-one of 22 (95%) eyes had seasonal allergies and 20 of 22 (91%) eyes had allergy-associated eye-rubbing behavior. Six of 22 (27%) had a diagnosis of Down's syndrome. Six patients were able to identify a traumatic inciting event: vigorous eye rubbing in 4 and traumatic contact lens insertion in 2. The affected area ranged from 7% to 100% of the corneal surface area and was related to disease duration and final visual acuity. Proximity of the area of edema to the corneal limbus ranged from 0 to 2.3 mm and was also related to prognosis. Three serious complications were observed: a leak, an infectious keratitis, and an infectious keratitis and coincidental neovascular glaucoma. Various medical therapies did not differ significantly in their effect on outcome, and ultimately 4 (18%) of 22 patients underwent penetrating keratoplasty. Best-corrected visual acuity was equal to or better than prehydrops visual acuity in 5 of the 6 patients in whom prehydrops visual acuity was known, without corneal transplantation. CONCLUSIONS: Allergy and eye-rubbing appear to be important risk factors in the development of hydrops. Visual results are acceptable in some patients without surgery. Close observation allows for the early detection and treatment of complications such as perforation and infection