Excimer laser photorefractive keratectomy.

The excimer laser has proved to be a precise and versatile tool for treating refractive errors. Excimer laser photorefractive keratectomy for myopia is now an established safe and effective alternative to contact lenses and glasses, and should be part of the ophthalmologist's standard armamentarium for treating this condition. This article provides a brief overview of the basic principles underlying excimer laser technology, as well as the surgical technique and postoperative management of myopic correction.

A population-based survey of hospitalized work-related ocular injury: diagnoses, cause of injury, resource utilization, and hospitalization outcome.

Occupational injury is a major source of ocular trauma and is often preventable. A statewide population-based survey of severe work-related ocular injury was generated by using the California Hospital discharge database to identify hospitalized ocular injury and workers compensation as principal payor to identify work-relatedness. Information concerning diagnoses, procedures, causes of injury, length of hospital stay, total hospital charges and disposition at hospital discharge were obtained for injuries occurring during the calendar year 1988. A total of 455 admissions for work-related ocular trauma were identified. The most common work-related ocular trauma diagnoses associated with hospitalizations were open globe injury (46%), adnexal wounds (20%), orbital fractures (11%), and traumatic hyphema (11%). The most common causes of work-related ocular trauma were foreign-body or projectile objects (19%), transport vehicles (18%), cutting or piercing objects (17%), and assaults (9%). Approximately 8% reported other than routine disposition at time of hospital discharge, including long-term nursing or rehabilitation services and death. Mean hospital stay when ocular trauma was the principal admitting diagnosis was 3.7 days. Results differed significantly for admissions reporting ocular trauma as the principal admitting diagnosis compared to admissions that did not. Hospitalized work-related ocular trauma is represented by a wide spectrum of injuries with substantial morbidity and economic costs. Projected to the United States population, these data indicate annual hospital charges excluding professional fees of $14.6 million when work-related ocular trauma is the principal admitting diagnosis and $40 million for admissions where ocular trauma is either a principal or secondary diagnosis.

Demographic and clinical characteristics of patients with diabetes presenting to an urban public hospital ophthalmology clinic.

OBJECTIVE: This study aims to describe the clinical and sociodemographic characteristics of patients with diabetes who are newly presenting to an inner city public hospital eye clinic. This study also aims to determine the prevalence and severity of ocular morbidity in this population at time presentation and to assess the adequacy of the ophthalmic surveillance to which this population was exposed before presentation. DESIGN: A clinic-based, cross-sectional study. PARTICIPANTS: A total of 118 consecutive patients with diabetes participated. METHOD: During a 2-month interval, all patients with diabetes newly presenting to the Los Angeles County King-Drew Medical Center eye clinic were recruited who were at risk for diabetic eye complications according to American Diabetes Association criteria. Each patient underwent a standardized interviewer-administered questionnaire and a comprehensive ophthalmic examination. RESULTS: Of the 118 patients, 65 (55%) were Hispanic and 51 (43%) were African American. Forty-six percent had a grade school education or less, 91% were unemployed, and 64% had no health insurance. Type two diabetes was predominant (91%), including 24 (22%) of new onset. Thirty-six patients with diabetes (31%) reported duration of diabetes greater than 10 years at time of presentation. At time of presentation, 62% had clinically apparent ophthalmic disease, whereas 40% had advanced ocular disease, including 6.8% of the sample that were legally blind. Sixty-nine patients (58.5%) reported never having had a dilated fundus examination, whereas 31 (63%) of the 49 patients reporting a previous dilated examination were last examined more than 2 years before presentation. Timing of ophthalmic examination was classified as appropriate for 38 patients (32%), marginal for 20 patients (17%), and inappropriate for 60 patients (51%). CONCLUSION: In the setting of an inner city county hospital eye clinic, where the patient population is predominately minority and of low socioeconomic status, ophthalmic surveillance of high-risk patients with diabetes is inadequate and advanced disease often is present at initial presentation. Strategies must be developed to increase the routine use of eye services within this population.

Topographic detection of photorefractive keratectomy.

PURPOSE: This study aimed to evaluate the sensitivity and specificity of subjective review of corneal topography to detect patients who have undergone photorefractive keratectomy (PRK). METHODS: Topographic maps from 3 different devices were obtained from 19 patients with postoperative PRK and 9 control subjects with emmetropia and 10 control subjects with myopia. Each image was printed in an absolute and relative scale (total of 228 maps) and graded for overall shape and pattern. Fifteen masked reviewers independently rated each map as either postoperative PRK or not. RESULTS: The overall sensitivity (ability to detect PRK) and specificity rates (ability to exclude control subjects) by reviewers were 65% and 93%, respectively. Sensitivity was influenced independently by the scale (relative, 68%; absolute, 62%; P < 0.01), experience of reviewer (experienced, 77%; inexperienced, 53%; P < 0.001), and device (Alcon, 67 +/- 29.9; Eyesys, 75 +/- 29.4%; and Tomey, 54 +/- 31.7%; P < 0.001). Low levels of preoperative myopia were consistently more difficult to detect than higher levels (low myopia -1.50 to -2.99 diopters [D] sensitivity: 53 +/- 34.5%; medium level -3.00 to -4.49 D: 67 +/- 28.9%; and high level -4.50 to -6.00 D: 77 +/- 21.1%; P < 0.0001). Differences in specificity between experienced and inexperienced reviewers were obtained when maps had a homogeneous topographic pattern (97 +/- 5.6% and 85 +/- 13.7%, respectively; P < 0.05). Several control topography patterns (e.g., homogeneous, focal, and keyhole) were disproportionately more difficult to correctly identify on the Eyesys device. CONCLUSIONS: Topographic experience is a significant factor influencing the correct identification of PRK. Techniques also can be used to enhance detection, such as the use of different devices and scales. However, if subjective review of topography is used as the only method of detection, many patients with PRK will not be identified properly. In addition, the most prevalent preoperative myopic category in the general population (myopia < -3.00 D) also is the most difficult to detect after treatment. This reduces the usefulness of topography as a screening tool. Other techniques are needed to improve the detection of patients with postoperative PRK.

Teleophthalmology: rationale, current issues, future directions.

Relatively little information exists concerning the delivery of ophthalmic services via telemedicine, yet ophthalmology is particularly amenable to the utilization of such applications. This paper discusses the technological issues pertinent to the research, development, and assessment of teleophthalmology delivery systems and begins to define the parameters that will determine the sustainability of teleophthalmology. A prototype urban teleophthalmology delivery system is presented in the context of improving access to eye care for an underserved inner-city population. Potential enhancements to the prototype telephthalmology system are discussed.

Demographic factors in a population-based survey of hospitalized, work-related, ocular injury.

PURPOSE: To obtain population-based estimates of the incidence of severe work-related ocular trauma and to identify demographic factors related to increased risk of this type of injury. METHODS: A statewide population-based survey of severe work-related ocular injury was performed using hospital discharge data. These data were derived from all inpatient admissions to nonfederal, acute-care hospital facilities in the state of California during 1988. Worker's compensation was used as the principal payor code to establish the work-relatedness of a given ocular injury. Census data for the state of California were used to obtain population denominators. RESULTS: Two hundred sixty-nine (approximately 14.3%) of all admissions for which ocular trauma was the principal diagnosis (1,876) were work related. Annual incidence for severe work-related ocular injury was 1.76 per 100,000 employed persons when ocular trauma was the principal diagnosis and 2.98 per 100,000 employed persons when ocular trauma was a principal or secondary diagnosis. Projected to the working-age United States population (128 million) these annual rates correspond to an estimated 2,165 acute hospitalizations for work-related ocular trauma as the principal diagnosis, and an estimated 3,745 acute hospitalizations for work-related ocular trauma as a principal or secondary diagnosis. Incidence of severe work-related ocular injury was highest among men, Hispanics, and individuals 20 to 24 years of age (5.02, 3.72, and 4.64 per 100,000 employed per year, respectively). CONCLUSIONS: The workplace accounts for a substantial proportion of severe ocular injury. Demographic groups at highest risk for this type of injury are men, Hispanics, and young adults.

Corneoscleral laceration caused by air-bag trauma.

PURPOSE: To report a case of a corneoscleral laceration sustained as a direct result of inflation of a driver-side air bag. METHODS: A patient who sustained a severe ocular injury in a low-speed motor vehicle accident underwent clinical and radiologic examination and subsequent treatment. RESULTS: The left eye underwent primary repair of a complex corneoscleral laceration. Two weeks postoperatively, visual acuity in the left eye remained at bare hand motion. CONCLUSION: Although air-bag-related eye trauma may be relatively infrequent, the severity of the injuries incurred warrant research efforts to explore new air-bag designs that minimize the risk of ocular injury.

The role of smears, cultures, and antibiotic sensitivity testing in the management of suspected infectious keratitis.

PURPOSE: To examine the role of routine smears, cultures, and antibiotic sensitivity testing in the treatment of suspected infectious keratitis. METHODS: A retrospective chart and laboratory data review was performed for 81 consecutive patients seen in the Los Angeles County/University of Southern California Department of Ophthalmology between June 1991 and December 1993 with a primary diagnosis of community-acquired infectious keratitis. No patients were treated with antibiotics before evaluation in the author's department, and all underwent corneal scrapings for gram-stain and bacterial, fungal, and mycobacterium cultures. Ulcers were classified as moderate or severe. All initially were treated as inpatients with a regimen including fortified cefazolin and a fortified aminoglycoside. RESULTS: Of 81 patients, 74 ulcers were either culture- negative (n=18) or grew bacteria (n=56). Fungal infection was suggested in seven patients. Of the nonfungal ulcers, 33 were classified as moderate, and 41 as severe; all moderate ulcers improved without requiring a modification in antibiotic treatment, whereas 3 severe ulcers required a change in treatment. CONCLUSION: Most community-acquired bacterial ulcers resolve with broad spectrum empiric therapy. Alternatives to universal culture and sensitivity testing that might be considered include selectively performing cultures for more severe or suspected non-bacterial ulcers or routinely obtaining cultures in all cases, but pursuing identification and sensitivity studies only when those data are required for therapy modification.

Evaluation of intraocular lens power calculation formulas in the triple procedure.

PURPOSE: To determine whether the choice of intraocular lens (IOL) power formula improves IOL power predictions and whether personalized constants within the IOL power formula are critical factors in improving refractive predictions after combined penetrating keratoplasty, cataract extraction, and IOL implantation. METHODS: Records of 46 patients who had the triple procedure between January 1988 and December 1992 were evaluated using the SRK II, SRK/T, Holladay, and Hoffer Q formulas to predict the postoperative spherical equivalent refractions for implanted lens power. Calculations were carried out with and without the use of personalized constants. The predictive accuracy of each formula was assessed by comparing the actual postoperative spherical equivalent refractive error with that predicted by the formulas. The predictive error and the distribution of predictive errors were used to assess predictive accuracy. RESULTS: There was no difference in the mean absolute predictive errors and the distribution of predictive errors for the four formulas evaluated (P > .05). The use of personalized formula constants significantly reduced the mean absolute predictive error for the SRK II, SRK/T, and Holladay formulas (P < .05) and approached significance for the Hoffer Q formula. CONCLUSION: The findings suggest that the choice of IOL power formula does not affect IOL power predictions in the corneal triple procedure; however, personalized constants within a formula appears to be a critical factor in improving postoperative refractive predictions.

Endophthalmitis and orbital cellulitis after radial keratotomy.

PURPOSE: To report the findings concerning three patients with endophthalmitis and one with panophthalmitis and orbital cellulitis radial keratotomy surgery. METHODS: One man referred with panophthalmitis and orbital cellulitis and three women referred with endophthalmitis were treated. RESULTS: After radial keratotomy surgery, during which no microperforation or macroperforation had been reported, a severe Pseudomonas panophthalmitis and orbital cellulitis developed in the man. All vision was lost in that eye. Staphylococcus epidermidis endophthalmitis developed in one woman, Streptococcus pneumoniae endophthalmitis in the second woman and Pseudomonas endophthalmitis in the third woman, after undergoing radial keratotomy procedures during which microperforations occurred. In the latter patient, bilateral simultaneous surgery was performed, but only one eye became infected. The latter two infections resulted in light perception and hand motion vision respectively. In three cases, an initial keratitis was located in the inferior cornea. CONCLUSIONS: Severe bacterial endophthalmitis can occur after radial keratotomy surgery, even in the absence of microperforation during the procedure. Any evidence of postoperative keratitis must be regarded seriously and treated aggressively. Despite use of this approach, the effect on final visual acuity can be devastating.

The importance of initial management in the treatment of severe infectious corneal ulcers.

PURPOSE: To identify factors that influence the outcome of patients with severe infectious corneal ulcers. METHOD: A retrospective review was performed of the hospital records of all such patients admitted to the Doheny Eye Hospital during a 30 month period. Outcome variables examined were change in visual acuity, duration of hospitalization, hospital charges, and percentage of patients who required penetrating keratoplasty. RESULTS: Sixty-two ulcers were included. An organism was identified and antibiotic sensitivities established in 52 patients (84%). Inpatient therapy involved a combination of fortified aminoglycoside and cephalosporin antibiotics in 39 patients (63%) and was found to be appropriate on the basis of sensitivity studies in 49 (94%) of 52 patients. Inappropriate initial treatment was related to increased hospital charge (P = 0.024) as well as increased risk of penetrating keratoplasty (P = 0.001). CONCLUSIONS: Appropriate initial therapy is most critical in the course of serious corneal ulcers, and aggressive, broad-spectrum antibiotic coverage is advocated.

Changing indications for penetrating keratoplasty, 1989-1993.

The purpose of this study was to identify new trends in the changing indications for penetrating keratoplasty. We retrospectively reviewed the clinical and pathologic diagnoses of 1,104 corneal buttons that had been submitted to the Estelle Doheny Eye Pathology Laboratory, Los Angeles, during the 5-year period 1989-1993. The leading indications, in order of decreasing frequency, were pseudophakic corneal edema (24.8%), regrafts (21.3%), scarring with or without chronic inflammation (11.1%), keratoconus (7.1%), aphakic corneal edema (6.4%), and ulcerative conditions (5.8%). The incidence of pseudophakic corneal edema remained stable over the study period and was actually surpassed by regraft in the last year of the study. Although pseudophakic corneal edema remains the predominant indication for penetrating keratoplasty, our findings suggest that its occurrence rate has begun to level off.

Chronic blepharitis: a review.

Although blepharitis is one of the most common ocular disorders encountered in clinical practice, it may constitute a diagnostic and therapeutic enigma. Attempts to classify this disorder are difficult because of the complex mechanisms underlying its pathogenesis. Clinical and laboratory investigations have clearly established bacteria and meibomian gland abnormalities as major etiologic determinants. In addition, changes in tear film dynamics and underlying dermatologic abnormalities appear to contribute to pathogenesis. The clinical manifestations primarily occur along the lid margin, and the predominant symptoms are itching and burning. Currently there is no cure for this condition. In the case of staphylococcal blepharitis, for example, there is no long-term cure because patients are likely susceptible to the causative organism(s), and thus become reinfected. Therapy is aimed then at bringing the disease process under control. A therapeutic regimen consisting of lid hygiene, topical or systemic antibiotics, and tear replacement seems to be most effective in alleviating symptoms and maintaining disease control but requires prolonged treatment.