Endophthalmitis is a virulent ocular inflammation typically developing suddenly and progressing rapidly. To better understand the incidence and factors predisposing to infection and influencing outcome, records of 114 patients with endophthalmitis hospitalized at one institution from 1980 to 1986 were reviewed. An infectious origin was confirmed in 79 patients (69%). The most common pathogens included staphylococcal species (Staphylococcus epidermidis, 33 cases; Staphylococcus aureus, 8 cases), streptococci (18 cases), gram-negative organisms (10 cases), and fungi (7 cases). Predisposing factors for infective endophthalmitis included preceding ocular surgery (67%), penetrating trauma (13%), systemic infection (11%), and periocular infection (5%). Despite vitrectomies and aggressive use of antibiotics, 42 patients (53%) with infective endophthalmitis suffered major visual loss. Morbidity was less pronounced with infection caused by S. epidermidis (23%; P less than .05). Patients with infective endophthalmitis more likely required repeated vitrectomies, were hospitalized longer, and had a worse outcome (as measured by complete enucleation) than those with "sterile" endophthalmitis. On the basis of these data, empiric vancomycingentamicin might be initiated in patients with endophthalmitis. Studies to define optimal management are needed, because the morbidity associated with this entity remains pessimistically high despite state-of-the-art treatment.

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Raman analyses of the lifetimes of phonons in GaN and AlN crystallites of wurtzite structure are presented. In order to ensure the accuracy of the measurement of the phonon lifetimes, an experimental procedure to eliminate the broadening due to the finite slit width was performed. The lifetime analyses indicate that the phonon lifetimes in AlN as well as in GaN fall into two main time regimes: a relatively long time of the E 2 1 mode and much shorter times of the E 2 2 , E1͑TO͒, and A1͑TO͒ modes. The lifetimes of the E 2 1 , E 2 2 , E1͑TO͒, A1͑TO͒, and A1͑LO͒ modes of an high-quality AlN crystallite are 4.4, 0.83, 0.91, 0.76, and 0.45 ps, respectively. Moreover, the lifetime of the A1͑LO͒ mode found in this study is consistent with the current phonondecay model of that mode in wurtzite structure materials. The lifetimes of E 2 1 , E 2 2 , E1͑TO͒, and A1͑TO͒ of a GaN crystallite were found to be 10.1, 1.4, 0.95, and 0.46 ps, respectively. The A1͑LO͒ mode in the GaN was not observed and its absence is attributed to plasmon damping. The lifetime shortening due to impurities was also studied: the lifetimes of the Raman modes of an AlN crystallite, which contains about two orders of magnitude more Si and C impurities relative to the concentration of the high-quality crystallite were found to be 50% shorter. ͓S0163-1829͑99͒04419-7͔

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