L. David Ormerod

Endophthahiiitis Caused by the Coagulase-negative Staphylococci: I. Disease Spectrum and Outcome

PURPOSE The coagulase-negative staphylococci are the most common causes of postoperative endophthalmitis. This study investigates the variability in the disease spectrum and visual outcome of coagulase-negative staphylococcal endophthalmitis in a large, single-center series. METHODS Ninety consecutive cases of coagulase-negative staphylococcal endophthalmitis were investigated retrospectively from two time periods, 1978 to 1982 and 1985 to 1987, separated by a transitional period in cataract surgery technique. Using a detailed protocol, inpatient, outpatient, and microbiologic records were analyzed. Six-month visual acuity results were obtained. RESULTS Diagnosis frequently was delayed, often suspected only after hypopyon development. Thirty-seven percent of patients presented more than 1 week after the inoculating event, and 13% presented after more than 1 month. Variable asymptomatic intervals and gradually worsening inflammatory prodromes are noted. Painless endophthalmitis occurred in 16%. Non-epidermidis infections comprised 28%. With vitrectomy/intraocular antibiotic management, 38% and 68% achieved visual acuities of 20/50 and 20/400, respectively. Overall, 10% of patients developed late retinal detachments. This occurred in only 4% of patients, with endophthalmitis occurring after cataract surgery. CONCLUSION Ophthalmologists should become familiar with the emerging concepts of delayed-onset, chronic, and often painless endophthalmitis in which the coagulase-negative staphylococci play a prominent role.

Endophthalmitis Caused by the Coagulase-negative Staphylococci: 2. Factors Influencing Presentation after Cataract Surgery

PURPOSE This study, comprising 60 patients with coagulase-negative staphylococcal endophthalmitis which occurred after cataract surgery, was designed to define the variation in disease presentation and visual outcome and to evaluate statistically the role of the primary surgery and its management. METHODS An intensive evaluation of microbiological, inpatient, outpatient, and cataract surgery charts was made retrospectively using a standardized protocol. The predictive value of surgical, iatrogenic, and clinical factors was analyzed for their influence on defined aspects of the disease pattern and of the visual results using multiple regression models, via a stepwise technique. RESULTS There was commonly a significant asymptomatic latent period after cataract surgery. The median diagnostic delay was 7 days; 22% of patients presented after 2 weeks and 12% after 1 month. Symptoms progressed longer than 3 days in 25% of patients. Ten percent had no pain. Clinical variation proved largely unrelated to cataract surgery events and postoperative management; bacterial factors were implicated. Good visual outcome was associated statistically with intensive topical corticosteroid in the symptomatic period, but was negatively associated with operative subconjunctival corticosteroid. CONCLUSIONS The clinical variation in cases of postoperative coagulase-negative staphylococcal endophthalmitis poses particular problems for diagnosis in the outpatient setting. Surgical and perioperative events (except corticosteroid use) probably can be disregarded in studies of endophthalmitis management.

Infectious Crystalline Keratopathy

Infectious crystalline keratopathy (ICK) is a chronic corneal infection characterized by interlamellar plaques of gram-positive coccal bacteria in the absence of inflammatory cells. It generally occurs within a corneal graft. Viridans streptococci are usually isolated, but the clinical response to antibiotics is poor and disparate with the in vitro antimicrobial sensitivities. These features suggest the possibility of unusual bacterial factors in pathogenesis. Four cases caused by nutritionally variant viridans streptococci are described. The organisms were fully characterized. They have a rare nutritional requirement for pyridoxal and require defined culture conditions and specific identification. Nutritional variant streptococci (NVS) are principally described as causing endocarditis, another infection involving an avascular collagenous tissue, and exhibiting similar biologic behavior. Electronmicrographic evidence is also adduced that suggests the possible importance of intracorneal glycocalyx deposition. Such factors might explain the anomalous clinical characteristics of this condition.

Practical anterior segment fluorescein angiography.

Anterior segment fluorescein angiography is a useful investigative technique for diagnosing and assessing anterior segment disease. However, a number of technical problems are inherent in current methodology, such as confounding reflexes, off-axis illumination, and shallow depth of field. We developed a simple technique using readily available equipment, polarized light, and an easy-to-construct auxiliary bracket to provide an inexpensive and optimal photographic system for anterior segment fluorescein angiography.