CT definition of the surgical apex in the orbit.

The orbital apex is an undefined but well understood concept of Orbital Surgeons. We sought to determine the surgical apex area specifically where the volume ratio decreases significantly impacting on the optic nerve. A retrospective analysis using PACS program processing, measured the right retrobulbar space volume changes in 100 randomly selected cases without orbital pathology where CT was performed for non-ophthalmic indications. Volume of the retrobulbar space was measured between two recognizable landmarks. The first landmark being the point of exit of the optic nerve from the eye and the second landmark the optic nerve's point of exit from the orbit. The measured length between these two points was divided into five equal segments, V1-V5. The volumes of all 5 segments were compared and the most significant area of volume depletion was established. The mean numeric value of measured orbital volumes was compared. A ratio difference of V1/V2 was less than 2, V2/V3 was 2.32 (± 0.27), V3/4 was 3.24 (± 0.39), and V4/V5 was 5.67 (± 1.66). The most remarkable difference in ratio was between V4 and V5 (mean 5.67 ± 1.66 with p < .0001). The V3 segment (the posterior 3/5 of the retrobulbar space volume) is the location where decrease in orbital volume impacts, and measured ratios are statistically significant. We defined the surgical apex as the posterior 3/5 of the retro-bulbar orbital space. It is consequently the area of higher risk for optic nerve compression. This definition could be routinely utilized by ophthalmologists and neuroradiologists when evaluating masses affecting the orbit.

Qualitative Evaluation of the 10-2 and 24-2 Visual Field Tests for Detecting Central Visual Field Abnormalities in Glaucoma.

PURPOSE: To examine whether glaucomatous central visual field abnormalities can be more effectively detected using a qualitative, expert evaluation of the 10-2 test compared with the topographically corresponding central 12 locations of the 24-2 test (C24-2). DESIGN: Cross-sectional study. METHODS: Eyes with a glaucomatous optic nerve appearance or ocular hypertension (n = 523) and healthy eyes (n = 107) were included as cases and control subjects, respectively. The 10-2 and C24-2 visual field results of all eyes were graded by 4 glaucoma specialists for the probability that central visual field abnormalities were present. RESULTS: The sensitivity of the 10-2 and C24-2 tests for detecting the cases at 95% specificity were not significantly different (e.g., 32.2% and 31.4%, respectively, for grader 1, P = .87; all graders P ≥ .25). At 95% specificity, the pattern standard deviation values from these tests had a similar sensitivity to the qualitative evaluation for the C24-2 test for all graders (P ≥ .083), but it had a significantly higher sensitivity than the qualitative evaluation for the 10-2 test for 3 graders (P ≤ .016). CONCLUSIONS: The similarity in performance of the 10-2 and C24-2 test suggests that the increased sampling density of the former does not significantly improve the detection of central visual field abnormalities, even when based on expert assessment. These findings should not be taken to mean that the 10-2 test is not useful, but it underscores the need for its utility to be clearly established before incorporating it as routine glaucoma standard of care.

[MINIMALLY INVASIVE GLAUCOMA SURGERIES].

INTRODUCTION: The goal of all glaucoma surgery is to lower eye pressure to prevent or reduce damage to the optic nerve. Standard glaucoma surgeries - trabeculectomy, ExPRESS shunts and external tube-shunts like the Ahmed and Baerveldt valves - are major surgeries. While they are very often effective at lowering eye pressure and preventing progression of glaucoma, they have a long list of potential complications. Minimal invasive glaucoma surgery (MIGS) is a group of operations that have been developed in recent years to reduce some of the complications of most standard glaucoma surgeries. MIGS procedures work by using microscopic-sized equipment and tiny incisions. The purpose of this study is to review the available MIGS currently in use, their benefits and limitations.

Peripartum cesarean hysterectomy: critical analysis of risk factors and trends over the years.

OBJECTIVE: To investigate time trends and risk factors for peripartum cesarean hysterectomy. METHODS: A population-based study comparing all deliveries that were complicated with peripartum hysterectomy to deliveries without this complication was conducted. Deliveries occurred during the years 1988-2007 at a tertiary medical center. A multiple logistic regression model was constructed to find independent risk factors associated with peripartum hysterectomy. RESULTS: Emergency peripartum cesarean hysterectomy complicated 0.06% (n=125) of all deliveries in the study period (n=211,815). The incidence of peripartum hysterectomy increased over time (1988-1994, 0.04%; 1995-2000, 0.05%; 2001-2007, 0.095%). Independent risk factors for emergency peripartum hysterectomy from a backward, stepwise, multivariable logistic regression model were: uterine rupture (OR=487; 95% CI 257.8-919.8, p<0.001), placenta previa (OR=66.4; 95% CI 39.8-111, p<0.001), postpartum hemorrhage (PPH) (OR=40.8; 95% CI 22.4-74.6, p<0.001), cervical tears (OR=22.3; 95% CI 10.4-48.1, p<0.001), second trimester bleeding (OR=6; 95% CI 1.8-20, p=0.003), previous cesarean delivery (OR=5.4; 95% CI 3.5-8.4, p<0.001), placenta accreta (OR=4.7; 95% CI 1.9-11.7, p=0.001), and grand multiparity (above five deliveries, OR=4.1; 95% CI 2.5-6.6, p<0.001). Newborns of these women had lower Apgar scores (<7) at 1 and 5 min (32.7% vs.4.4%; p<0.001, and 10.5% vs. 0.6%; p<0.001, respectively), and higher rates of perinatal mortality (18.4% vs. 1.4%; p<0.001) as compared to the comparison group. CONCLUSION: Significant risk factors for peripartum hysterectomy are uterine rupture, placenta previa, PPH, cervical tears, previous cesarean delivery, placenta accreta, and grand multiparity. Since the incidence rates are increasing over time, careful surveillance is warranted. Cesarean deliveries in patients with placenta previa-accreta, specifically those performed in women with a previous cesarean delivery, should involve specially trained obstetricians, following informed consent regarding the possibility of peripartum hysterectomy.