The influence of accommodative insufficiency on reading

Background: It is not known how accommodative insufficiency influences reading performance. Methods: Reading eye movements were recorded before and after treatment for accommodative insufficiency in 12 school children (eight to 16 years). During the eight‐week treatment period all subjects wore a +1.00 D addition when reading. Results: Large variations in reading patterns were found. Despite successful accommodative treatment (p < 0.001), no correlation was found to suggest improved reading velocity. Discussion: Three case reports will be presented and the implications discussed.     

The effect of vertical gaze position on ocular tear film stability

Background: An enlarged exposed ocular surface area is known to degrade tear film stability. Little is known of how tear film stability alters with vertical gaze and the change of palpebral fissure height Methods: Tear film break‐up time (TBUT; fluorescent dye) and palpebral fissure height were measured in three vertical gaze positions (primary position and 20 degrees up and 20 degrees down) on 23 healthy volunteers. The effect of gaze direction on TBUT was analysed by ANOVA. Results: Gaze had a significant influence on tear film stability [F(2,44) = 27.6, p < 0.001]. In up‐gaze with an enlarged palpebral fissure height (11.1 ± 1.4 mm), TBUT was degraded (17.3 ± 12.7 seconds). In down‐gaze and decreased palpebral fissure height (6.7 ± 1.2 mm) TBUT was extended (43.5 ± 35.4 seconds). Conclusion: Ocular tear film stability alters with vertical gaze. Our hypothesis is that the change of the palpebral fissure height and the exposed ocular surface area alters the thickness of the lipid layer and with it tear film evaporation.     

A simple technique for decompression of distended gallbladder during laparoscopic cholecystectomy

During laparoscopic cholecystectomy, distended gallbladder can create exposure difficulties, that precludes adequate visualization, thus rendering laparoscopic dissection impossible and even unsafe. To overcome this problems, we devised a simple technique for the decompression of distended gallbladders.     

Low-pressure laparoscopy may ameliorate intracranial hypertension and renal hypoperfusion

BACKGROUND: Increased abdominal pressure is associated with elevations in the intracranial pressure (ICP) and impaired renal function. These adverse effects are potentially important in clinical situations such as severe abdominal trauma and laparoscopic donor nephrectomy. It was hypothesized that the secondary elevation of ICP leads to release of vasoconstrictors, which may affect renal function by decreasing the renal blood flow (RBF). We investigated the effect of laparoscopy on ICP and renal blood flow in a porcine model. MATERIALS AND METHODS: The abdominal pressure of swine (N = 5; 20-25 kg) was gradually increased from baseline to 5, 15, and 25 mm Hg by insufflation of nitrogen into the abdominal cavity. The ICP was measured using a Camino monitor, and RBF was simultaneously measured using a Transonic Doppler probe placed on the renal artery. Results were analyzed using repeated measures ANOVA and the paired t-test. RESULTS: No significant change from baseline was observed in ICP and RBF when the abdominal pressure was 5 mm Hg. However, both ICP and RBF were affected by increasing the abdominal pressure to 15 and 25 mm Hg (P = 0.035 and 0.04 for ICP and P = 0.074 and 0.034 for RBF, respectively). CONCLUSIONS: Low-pressure laparoscopy may reduce the adverse effects of pneumoperitoneum on ICP and RBF. It may be advisable to use low pressures in laparoscopic surgery, especially when changes in ICP or renal perfusion may have significant clinical implications.     

Neuroendocrine and biologic features of primary tumors and tissue in pulmonary large cell carcinomas

BACKGROUND: Because biological behavior in lung tumors with neuroendocrine differentiation is highly dependent on cell death (apoptosis) and angiogenesis, p21(waf1/cip1) and microvessel density have been targeted as potentially useful tumor markers. We sought to validate the importance of p21(waf1/cip1) and microvessel density and study their interrelationship, analyzing clinical factors, subclassifications, and tumor and stromal markers. METHODS: We examined p21(waf1/cip1) and other markers in tissue from 61 patients with surgically excised large cell carcinomas. The amount of tumor staining for p21(waf1/cip1) and microvessel density was evaluated by immunohistochemistry and morphometry. The study outcome was survival time until death from recurrent lung cancer. RESULTS: Multivariate Cox model analysis demonstrated that after surgical excision, histologic subtypes were significantly related to survival time (p = 0.02), but quantitative staining of the tumor for p21(waf1/cip1) and microvessel density added prognostic information and these variables were more strongly prognostic than histologic subtype (p = 0.00). Cut points at the median staining of 3.5% and 3.0% for p21(waf1/cip1) and microvessel density, respectively, divided patients into two groups with distinctive survival times. Patients with p21(waf1/cip1) staining of more than 3.5% and microvessel density staining of more than 3.0% had a median survival time of 14 months. CONCLUSIONS: Tumor staining for p21(waf1/cip1) and microvessel density in resected large cell carcinomas and certain other types of lung tumors was strongly related to survival. Patients with more than 3.0% staining in their tumors were at high risk of death from lung cancer and may be an appropriate target for prospective studies of adjuvant chemotherapy after surgical resection.