Results of bilateral photorefractive keratectomy

OBJECTIVE: To study the refraction and potential risks of bilateral photorefractive keratectomy for myopia. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Four hundred eighteen consecutive patients (836 eyes) with myopia from -18 to -0.50 diopters (D) had bilateral simultaneous refractive surgery. INTERVENTION: Refractive surgery was performed with the Nidek EC-5000 slit-scanning excimer laser (Nidek Co., Tokyo, Japan). MAIN OUTCOME MEASURES: Manifest refraction, Snellen best spectacle-corrected visual acuity (BSCVA) and uncorrected visual acuity, haze, and halos were evaluated for 12 months after surgery. Both eyes of each patient were examined at the same follow-up after initial treatment. RESULTS: At 12 months after surgery, 95% of eyes were within +/- 1D of emmetropia, and 0.4% of patients had residual anisometropia more than 2 D. Thirty-three eyes (3.9%) were retreated, whereas 5 patients (1.2%) had retreatments in both eyes. Odds ratios between unilateral versus bilateral postoperative events were evaluated for the retreatments (1:0.22; P = 0.001), undercorrections more than 1 D (1:0.17; P < 0.0001), overcorrections more than 1 D (1:0.23; P < 0.0001), loss of 1 line of BSCVA (1:0.44; P < or = 0.002), and loss of 2 lines of BSCVA (1:0.18; P = 0.013). At 12 months after surgery, one eye with a loss of 2 lines of BSCVA was treated for haze more than 1; the fellow eye had haze 0.75. No patient had bilateral haze more than 1. At 12 months after surgery, no patient lost 2 lines of BSCVA in both eyes. There was a higher incidence of halos in both eyes rather than in one eye only (odds ratio: 4.17; P < 0.0001). No postoperative infections occurred. CONCLUSIONS: Bilateral events occurred approximately 2.5 to 4 times less often than unilateral events, except for the incidence of halos. The calculated odds ratio did not show an increased risk for the fellow eye while performing bilateral surgery, although not exempted from the risk of infection. It may be difficult to predict a complication in the fellow eye based on the results of the first operated eye.     

The neurogenic mechanisms of ocular inflammation and their modulation under local treatment with indomethacin

Neurogenic modulation of the inflammation is an essential mechanism of initiate and conditionate an inflammatory reaction. SP, NKA and NKB--neurokinins are involved in the modulation of the local ocular inflammation initiated by the surgical perforating trauma of the anterior pole. They determine the increase of vascular permeability and the breakdown of the aqueous-humor-blood barrier by direct action on the endothelial vascular receptors and by indirect mechanism (releases prostaglandins). This effect is demonstrated by the increase of the blue Evans concentration in the aqueous-humor after local application of SP, NKA and NKB in a dose-dependent manner. Local treatment with non-steroidal-antiinflammatory drugs like Indomethacin stabilizes the aqueous-humor-blood barrier, by diminishing the local effect of neurokinins. By increasing the vascular permeability SP, NKA and NKB make an important linkage by which the nervous system mediators contribute to the modulation of eye inflammatory responses whose intimate mechanisms are not entirely known yet.     

Secondary cataract treatment with laser YAG-ND

The purpose of the study is to present the favorable results of YAG: Nd laser capsulotomy for the treatment of secondary opacification of the posterior capsule, in our department. A 3 years retrospective study was performed. For 1440 cataract operations, most of them extracapsular extractions with PMMA IOL placed in the posterior chamber (ciliary sulcus or capsular bag), 285 laser capsulotomies were done. The results are presented statistically, including sex and age distribution, type of cataract surgery and implant, treatment protocol (number of sessions, number of impulses per session, energy per impulse) and complications. The frequency of secondary capsular opacification in our study is 19.78%. It is most important in the age group 60-70 years, where the surgery for cataract is performed more often. Capsulotomy was done after extracapsular extraction with IOL placed in the posterior chamber, but especially after extracapsular extraction without implant placement or with complications that have permitted only the use of an anterior chamber implant. Capsulotomy is performed in only one session in 88% of the cases. The energy per impulse is usually 3-5 mJ and the mean number of impulses per session is 10-30. There are few complications: transient elevation of intraocular pressure in 14.73%, discrete laser marks on the implant in 8.77% and moderate iritis in 1% of the cases. YAG: Nd laser capsulotomy appears to be a safe and efficient method of treating secondary cataract; it improved visual acuity in all cases, if different ocular pathology had not influenced it.     

Etiopathogenesis of autoimmune thyroiditis

Human autoimmune thyroid diseases include both autoimmune hypothyroidism (thyroiditis) and autoimmune hyperthyroidism (Graves' disease). Either of the two feature profuse thyroidal infiltrates of CD4+ and CD8+ T-cells and a biased intrathyroidal T-cell-receptor repertoire. Despite strong epidemiologic evidence in favor of a genetic component in the etiology of autoimmune thyroiditis, few hereditary risk factors have been consistently identified, which include a well-characterized series of HLA genes. These may account for the progression from a harmless autoimmune response characterized solely by production of autoantibodies to thyroglobulin to pathogenic autoimmunity where injury occurs to the thyroid cells. We hereafter summarize the role of inherited risk factors along with that of environmental risk factors. It was suggested that iodine increase the autoantigenic potency of thyroglobulin, a major pathogenic antigen in the induction of autoimmune thyroiditis. The clinical entities included together as autoimmune thyroiditis is shortly reviewed, along with the presentation of the common pathogenetic pathways. Unique features of each member of the group are further emphasized.     

Chronic lead poisoning-- a" forgotten" cause of anemia

We present the case of a female patient with a chronic hypersideremic anemia associated with digestive and neurological symptoms, with a long time ignored toxic history. The diagnose was based on very high levels of lead in serum and urine, very high levels of D-aminolaevulinic acid in the urine, and the presence of basophilic stippling of erythrocytes in the smear of the patient. Lead intoxication was due to ingestion of home-made alcohol (domestic devices made from lead mixtures) and of yogurt preserved in lead-glazed mugs.     

ARCON: experience in 215 patients with advanced head-and-neck cancer

PURPOSE: "ARCON" combines accelerated radiotherapy to counteract tumor repopulation with carbogen breathing and nicotinamide to reduce chronic and acute hypoxia. The aim of this Phase II study was to assess the feasibility, toxicity, and potential effectiveness of ARCON for advanced head-and-neck cancer. METHODS AND MATERIALS: The study included 215 patients with head-and-neck carcinoma distributed as follows: larynx, n = 100; hypopharynx, n = 50; oropharynx, n = 52; oral cavity, n = 13; Stage II, n = 8, Stage III, n = 71, and Stage IV, n = 136. Accelerated radiotherapy was given to a total dose of 64-68 Gy in 2-Gy fractions within 36-38 days. This was combined with carbogen breathing during irradiation and administration of nicotinamide (60-80 mg/kg) 1-1.5 h before irradiation. RESULTS: There was full compliance with carbogen breathing in 88% of the patients. A nicotinamide dose of 80 mg/kg produced severe nausea and vomiting, necessitating discontinuation of the drug, in 31% of the patients. Adjustment of the dose to 60 mg/kg and antiemesis prophylaxis reduced the discontinuation rate to 10%. Confluent mucositis was observed in 91% of the patients with a median duration of 6 weeks. Grade 4 late complications occurred in 5% of the patients. The actuarial 3-year local control rates were 80% for larynx, 69% for hypopharynx, 88% for oropharynx, and 37% for oral cavity tumors. For T3-4 tumors, the local control rates were 80% for larynx, 60% for hypopharynx, 87% for oropharynx, and 29% for oral cavity. Regional control rates were 100% for N0, 93% for N1, and 74% for N2 disease. CONCLUSION: ARCON yields high local and regional control rates in advanced head-and-neck carcinomas, and compliance is satisfactory and morbidity acceptable. The local control rate of 80% for T3 and T4 larynx carcinomas offers excellent possibilities for organ preservation.     

Risk of pulmonary embolism after a negative spiral CT angiogram in patients with pulmonary disease: 1-year clinical follow-up study

PURPOSE: To evaluate the effect of pulmonary disease on diagnostic utility of spiral computed tomographic (CT) angiography in clinical practice. MATERIALS AND METHODS: Three hundred thirty-four patients, including 215 patients with pulmonary disease (group 1) and 119 patients with no history of respiratory disorder (group 2), were referred for thin-collimation CT angiography of the pulmonary circulation as the first-line diagnostic test. Patients with negative angiograms who had not received anticoagulation therapy and who could be clinically followed up at 3 months, 6 months, and 1 year were considered in the final study groups (n = 185); 135 patients had lung disease (group 3), and 50 patients had no history of a respiratory disorder (group 4). RESULTS: Between groups 3 and 4, no significant differences were found in the referral location, age, and risk factors. Confident evaluation of pulmonary arteries down to the subsegmental level was performed in 31 (23%) patients in group 3 and in 15 (30%) in group 4 (P =.5). Three episodes of acute pulmonary embolism (PE), all fatal, were diagnosed in group 3 patients; two cases occurred 14 days and one case occurred 6 months after the negative spiral CT scan. The negative predictive value of spiral CT angiography was 98% (175 of 178) in the study group in which follow-up was performed, with no significant difference between the values in groups 3 (98% [132 of 135]) and 4 (100% [50 of 50]). CONCLUSION: Underlying respiratory disease does not affect the negative predictive value of thin-collimation CT angiography, which appears to be a reliable tool in the work-up in this subgroup of patients with acute PE.     

Effects of hyperoxygenation on FDG-uptake in head-and-neck cancer.

PURPOSE: Tumor hyperoxygenation results in high response rates to ARCON (accelerated radiotherapy with carbogen and nicotinamide). The effect of hyperoxygenation on tumor metabolism using [(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET) was investigated. METHODS: Within one week, FDG-PET was performed without and with hyperoxygenation by carbogen breathing and/or nicotinamide administration in 22 patients, eligible for ARCON for head-and-neck cancer. Maximum standardized uptake values (SUV(max)) in both scans and the relative change were calculated in the primary tumor and in normal muscle. RESULTS: Alteration of the tumor oxygenation state induced profound, but variable, metabolic changes (median DeltaSUV(max) -4%; range -61% to +30%). Metabolism in normal muscle was not affected. In three patients who did not achieve local tumor control, the SUV(max) after hyperoxygenation differed less than 5% change as compared to baseline, whereas 13 of the 16 patients with local tumor control showed a larger difference (p<0.05). CONCLUSION: Given the heterogeneous response pattern of nicotinamide and carbogen on FDG-uptake in head-and-neck carcinoma, the prognostic significance of semiquantitative FDG-PET before and after hyperoxygenation remains uncertain and requires confirmation in larger clinical studies before introducing the procedure as a predictive tool for oxygenation modifying treatments.