Prediction of refractive outcome after cataract surgery using partial coherence interferometry: comparison of SRK/T and Haigis formulae.

To compare the accuracy of the predictions of SRK/T and Haigis formulae, incorporating all the parameters calculated using Zeiss IOLMaster Scan, based on partial coherence interferometry, and to analyse the effect of updating or optimisation of the constants on the post-operative result. A retrospective study was done on 51 consecutive patients, who underwent phacoemulsification by a single surgeon with a temporal corneal incision and a standard Alcon Acrysof MA30 implant in the bag. The pre-operative data were measured using Zeiss IOLMaster scan, and the IOL power calculations were done using both SRK/T and Haigis formulae. The final implant power selection was based on SRK/T predictions. The patients were divided into three groups depending on the axial length, and the post-operative results were analysed at 4 weeks. The difference between the predicted value and the post-operative spherical equivalent was calculated for both the formulae, and a paired t test used for significance. The axial length ranged from 20.93 to 25.16 mm. The error for Haigis was less compared to SRK/T overall and SRK/T resulted in an average hypermetropia 0.69 D and Haigis resulted in an average myopia of 0.16 D. The comparison between SRK/T and Haigis and the updated version of both using the paired t test shows a statistically significant difference, the p values being <0.03 and <0.01, respectively. The updated Haigis Formula with the optimised constants was significantly more accurate than SRK/T formula.

Radio-decontamination efficacy and safety studies on optimized decontamination lotion formulation.

Objective of the present study was to optimize decontamination lotion and to evaluate its relative decontamination efficacy using three radio-isotopes (Technetium-99m, Iodine-131 and Thallium-201) as contaminants with varying length of contaminant exposure (0-1h). Experiments were performed on Sprague Dawley rat's intact skin and human tissue equivalent models. Rat's hair was removed by using depilator after trimming with scissors. Relative decontamination efficacy of the optimized lotion was investigated and compared with water as control. Static counts were recorded before and after decontamination using single photon emission computed tomography (SPECT). Measured decontamination efficacy (DE) values were analyzed using one way ANOVA and Student's t-test (p value<0.05) and were found statistically significant. Decontamination efficacy of the lotion was observed to be 90 ± 5%, 80 ± 2% and 85 ± 2%, for the (131)I, (201)Tl and (99m)Tc radio-contaminants respectively on skin. Reduced contaminant removal was recorded for the skin which was cleaned by depilator (50-60%). Skin decontamination was found more efficacious for rat skin decontamination than the human tissue equivalent model. Decontamination efficacy of the lotion against (99m)Tc was recorded 70 ± 15% at 0-1h on the tissue equivalent model. In vitro chelation efficacy of the lotion was also established by using the instant thin layer chromatography-slica gel (ITLC-SG) and >95% of (99m)Tc was recorded. Neither erythema nor edema was scored in the primary skin irritancy test visually observed for two weeks.

Do children with IBD really respond better than adults to thiopurines?

BACKGROUND AND OBJECTIVES: Children and adolescents with inflammatory bowel disease (IBD) have more extensive and severe disease than adults. Despite a lack of comparative studies, thiopurines are frequently cited as being more efficacious in children. To test this assertion, we compared the efficacy of thiopurines in children with IBD with that in adults matched for disease phenotype. PATIENTS AND METHODS: Fifty paediatric and adult patients with IBD started on a thiopurine were matched for sex, disease type, and extent. Retrospective data were obtained by electronic case note review, and corticosteroid-free clinical remission and tolerance rates at 6 months as well as relapse rates during the subsequent year were recorded. RESULTS: Adverse effects caused discontinuation of thiopurines in 1 of 50 children and 16% (8/50) of adults (P < 0.05). At 6 months, steroid-free remission was achieved in 30% (15/50) of children and 38% (19/50) of adults (P = 0.53). No differences in remission rates were seen according to disease type. At the end of the following year, 73% (11/15) of children and 68% (13/19) of adults remained in remission (P = 1). CONCLUSIONS: Thiopurines are tolerated better by children. When phenotype is matched, there is no difference in the therapeutic response to thiopurines between children and adults with IBD.

Laser vs ultrasound biometry--a study of intra- and interobserver variability.

BACKGROUND: Accurate biometry is of vital importance in achieving predictable postoperative refraction following cataract surgery. AIM: To evaluate the accuracy and consistency in biometry, achieved by the new generation laser biometric system in comparison with the ultrasound biometric system. METHODS: The study was randomized and prospective. Biometry was performed in 68 eyes of 39 patients by three groups of biometrists (expert, intermediate user, novice). Expert and intermediate users are compared as group A, and expert and novice are compared in group B. Axial length, anterior chamber depth (ACD), and keratometry results are compared by t-test analysis. RESULTS: Axial length measurement variation between expert and non experts was 10 times less using laser than ultrasound (P<0.001). ACD measurement variation was also significantly less when using laser compared to ultrasound (P=0.003). Need for some level of user training is indicated in ACD measurement since group A achieved more consistent readings than group B. Keratometry measurements on the laser system were unreliable due to high range of results. Biometric failure was seen in 12% of eyes undergoing laser and 1% undergoing ultrasound biometry. CONCLUSION: Axial length determination by laser biometry is more accurate and consistent at all levels of biometrist expertise, compared to ultrasound biometry. ACD and keratometry measurements on the laser systems need some degree of user training in order to produce consistent results.

Comparison between standard Goldmann applanation prism and disposable applanation prism in tonometry.

BACKGROUND: Disposable devices are increasingly becoming the preferred choice where possible in contact medical equipment. AIM: To evaluate the accuracy of the disposable applanation tonometer head as a potential substitute to the standard Goldmann applanation head. METHODS: The study was prospective. The intraocular pressure recordings in 80 eyes of 42 patients were compared using the disposable and standard Goldmann applanator heads. The Bland and Altman method of assessing agreement between two methods of clinical measurement was used in the analysis. RESULTS: The difference in the readings between the two types of tonometer heads was highly variable (mean difference=0.78 mm Hg, range=-1 to 11 mm Hg). This was because of the distortions on the applanating surface of the disposable device. When the readings associated with the defective heads were excluded, very strong agreement was obtained (mean=0.07 mm Hg, range=-1 to 2 mm Hg). CONCLUSION: Good agreement with standard Goldmann applanation is achieved with the disposable heads except where surface distortions induce significant errors. Careful inspection to ensure well-structured disposable units is imperative in disposable applanation tonometry.

CA-125 in fine-needle aspirates of solid tumors: comparison with cytologic diagnosis and carcinoembryonic antigen (CEA) assay.

UNLABELLED: One hundred and twenty-two fine needle aspirates (FNA) from female patients were studied to determine whether CA-125 assay contributed to cytologic diagnosis and CEA assay. Cytologic examination was done on Papanicolaou-stained smears and cell blocks, CEA by EIA (Abbott Laboratory, > 5 ng/ml cutoff) and CA-125 by RIA (Abbott Laboratory, North Chicago, IL, > 66 mu/ml cutoff). Final diagnosis were correlated with histologic diagnosis when available, clinical, radiologic studies, and follow-up. RESULTS: 29 benign, 93 malignant. Sensitivities and specificities: cytology, 91%, 100%; CEA: 59%, 86%; CA-125, 50%, 55%. CEA plus cytology sensitivity, 97%. CA-125 content was highest in endometrial/ovarian carcinoma (39,899 mu/ml) and < 5,000 mu/ml in other tumors and benign FNA in contrast to CEA which showed highest levels in carcinomas of colon, pancreas, and lung (> 280 ng/ml). While elevated CEA enhances the sensitivity of cytologic diagnosis of carcinomas of the colon, pancreas, and lung, low CEA and high CA-125 content supports an ovarian/endometrial primary.