Atrophy in Neovascular Age-Related Macular Degeneration: Age-Related Eye Disease Study 2 Report Number 15.

PURPOSE: To identify the development and progression of macular retinal pigment epithelial atrophy in eyes with neovascular (CNV) age-related macular degeneration (AMD) and to correlate with visual acuity (VA). DESIGN: Cohort study. PARTICIPANTS: Age-Related Eye Disease Study 2 (AREDS2) participants with intermediate AMD enrolled in a randomized controlled clinical trial of oral supplements. Analyses were conducted in the subset of AREDS2 participants who were also enrolled in the fundus autofluorescence ancillary (FAF) ancillary study. METHODS: Color photographs and FAF images were evaluated in eyes that developed CNV. Presence of geographic atrophy (GA) prior to the incidence of CNV and the development of macular atrophy following incident CNV were assessed. Areas of hypoautofluorescence representing atrophy were measured for area and macular involvement. Enlargement rate of atrophy and change in visual acuity over time were analyzed. MAIN OUTCOME MEASURES: incidence and enlargement rate of atrophy and VA changes in eyes with incident CNV. RESULTS: Incident CNV developed in 334 (9.2%) of eyes evaluated in the AREDS2 FAF substudy. Of these, 40% had macular atrophy at incidence of CNV with half of these attributable to pre-existing GA. Atrophy developed in 14.7 % of eyes over 4 years of follow-up. Mean area of atrophy was largest in eyes with pre-existing GA and CNV (5.17 mm2, p<0.001), and atrophy involved the center of the macula in > 65% of eyes. Mean VA letter score at the annual visit in which CNV was documented was similar in the three groups with atrophy; eyes with CNV and pre-existing GA, incident atrophy at the first visit with CNV, and atrophy during follow up (60 letters). Enlargement rate of atrophy was also similar in eyes in the three groups (1.23 - 1.86 mm2, p = 0.47). Eyes with macular atrophy lost more visual acuity compared to eyes without atrophy, particularly after 2 years of follow-up (-10.9 vs. - 3.6 letters, p = 0.07). CONCLUSION: Atrophy is commonly seen in neovascular AMD and often can be attributed to pre-existing GA. Macular atrophy and GA appear to be a continuum of the same disease process and are both associated with poor vision.

Cam and Pincer Type of Femoroacetabular Impingement.

Femoroacetabular impingement (FAI) has gained considerable attention for the past 20 years and has been accepted as a predisposing factor for early osteoarthritis in young patients, particularly in the population participating in sports. Patients with FAI typically present with deep, intermittent groin discomfort during or after activities involving repetitive or persistent hip flexion. Symptomatic improvement can be achieved from arthroscopic debridement of unstable cartilage flaps, shaving of cartilage irregularities, and surgical correction of deformity of the femoral head\endash neck junction. Early and correct diagnosis of FAI has paramount importance for appropriate and timely management of the disorder before the development of osteoarthritis. Magnetic resonance (MR) imaging offers a noninvasive means of assessing the degree of damage to cartilage and adjacent labrum and bone and also evaluating the effectiveness of treatment. This article describes the morphologic types of FAI with emphasis on MR findings.

A case of neonatal compartment syndrome: importance of early diagnosis in a rare and debilitating condition.

Neonatal compartment syndrome (NCS) is a rare condition that is often initially misdiagnosed because its skin lesions mimic several other more common diseases of the newborn. It has not been described in the pediatric literature thus far. Early diagnosis along with fasciotomy may be limb and function-sparing, but only in certain cases, because the exact time and duration of the initial insult and the full extent of damage at presentation is unknown in many cases. We present a case of NCS that was initially thought to be amniotic band syndrome, and delayed fasciotomy and debridement were performed once the correct diagnosis was made. We review the literature of this rare and debilitating condition and emphasize the importance of early diagnosis and intervention.

Reaction kinetics of acetone peroxide formation and structure investigations using Raman spectroscopy and X-ray diffraction.

Triacetone triperoxide (TATP) has been prepared in order to study the effect of pH and temperature on the reaction kinetics. Raman spectra of liquid mixtures of acetone and hydrogen peroxide were recorded versus time throughout the experiments. The spectral data of the liquid phases indicate that at 25 degrees C the reaction between acetone and hydrogen peroxide proceeds to form intermediates within one day. Based on the assumption that a likely reaction path involves a sequence of reaction steps between acetone and hydrogen peroxide, calculations of Raman spectra were performed using a density functional theory (DFT)/Hartree-Fock approach. It was not possible from this to assess with certainty which intermediate products formed most extensively in an acetone/hydrogen peroxide mixture. However, it was concluded that the most likely reaction mixture is a mixture of the different intermediate products and that the rate determining step is the ring closure. The reaction rate of TATP formation was found to increase with temperature and with sulfuric acid additions to the acetone/hydrogen peroxide mixture. By correlation of the induction time of TATP crystallization against pH it was shown that the reaction rate is first order with respect to the H+ concentration. Raman spectra of the precipitates from mixtures were in agreement with previous studies done for TATP, except in one case in which a crystal crystallized at 343 K had a distinctly different Raman spectrum. Comparison with calculated spectra revealed that the crystal produced could be diacetone diperoxide (DADP) or tetraacetone tetraperoxide (TrATrP). Single crystal X-ray diffraction analyses revealed that the crystal crystallized at 343 K was DADP.