Biomedical subjects

Edna Schechtman

Publications and source records attributed to Edna Schechtman.

23 records · Page 2Linked to original sources

PubMed2002

Pneumatic retinopexy: results in eyes with classic vs relative indications.

OBJECTIVE: To compare the results of pneumatic retinopexy in 3 groups of eyes with rhegmatogenous retinal detachment. METHODS: In this retrospective, consecutive study, 44 eyes of 44 patients who underwent pneumatic retinopexy were divided into 3 groups: eyes with vitreoretinal abnormalities (group A), pseudopakic or aphakic eyes (group B), and phakic eyes without vitreoretinal abnormalities (group C). RESULTS: Single retinopexy success was achieved in 10 (71%) of 14 eyes in group A, 7 (64%) of 11 eyes in group B, and 16 (84%) of 19 eyes in group C (P=.42). Final success after reoperation was achieved in 13 (93%) of 14 eyes in group A, 10 (91%) of 11 eyes in group B, and in all 19 eyes in group C (P=.44). In group B, the rate of single retinopexy success using cryotherapy was significantly higher (5/5; 100%) than when laser photocoagulation was used (1/5; 20%) (P=.015). The final visual outcome obtained in the 3 groups was similar. There were no significant intergroup differences in either early or late complications. CONCLUSIONS: The best results were achieved in eyes with classic indications for pneumatic retinopexy, though the differences between these results and those in the nonclassic indications were not significant. In pseudophakic or aphakic eyes, the rate of single operation success after cryopexy was significantly higher than the rate after laser photocoagulation.

Adolescent↗

PubMed2002

Microscope-induced retinal phototoxicity in cataract surgery of short duration.

OBJECTIVE: Microscope-induced retinal phototoxicity has been described after prolonged cataract surgery, usually in operations lasting longer than 100 minutes. The purpose of this study was to compare the features of microscope-induced retinal phototoxicity occurring in patients who underwent cataract surgery of short duration and long duration. DESIGN: A retrospective nonrandomized comparative trial. PARTICIPANTS: Thirty-four patients, whose medical records documented the development of phototoxic lesions in the retina as a result of cataract surgery, were divided into two groups: group A with 14 patients whose operating time was 30 minutes or less, and group B with 20 patients whose operating time was greater than 30 minutes. INTERVENTION: All patients underwent either phacoemulsification or extracapsular cataract extraction (ECCE) with implantation of an intraocular lens. RESULTS: The mean operating time was 23.1 minutes (range, 11-30 minutes) in group A, and 60.8 minutes (range, 34-123 minutes) in group B. Phacoemulsification was done more often in group A (P = 0.001) and ECCE in group B (P = 0.0003). A final refraction of +/- 1 D was achieved by 12 eyes (86%) in group A and by 12 eyes (60%) in group B (P = 0.11). The correlation between final refraction and duration of the operation was significant; the closer the final refraction approached to emmetropia, the shorter the duration of surgery (r = 0.53; P = 0.001). Diabetic retinopathy was more common in group A (P = 0.03). CONCLUSIONS: Phototoxic lesions of the retina may occur during cataract surgery even when the duration of the operation is short. The most relevant associated factors found in this study were correction approximating emmetropia and diabetic retinopathy.

Adult↗

PubMed2002

Headway feedback improves intervehicular distance: a field study.

The effectiveness of a headway measuring and recording device was evaluated in terms of its ability to increase drivers' car-following distance. Forty-three drivers first drove for approximately 3 weeks without headway feedback and then for approximately 3 more weeks with immediate time headway (THW) feedback. Whenever the THW decreased to 1.2 s or less a red warning light came on, and whenever the THW decreased further to 0.8 s or less a buzzer was also sounded. The results showed that prior to receiving THW information,drivers drove at shorter headways than after they received that information. The effect of the feedback was to reduce the time spent in short headways (< or = 0.8 s) by approximately 25% (from 20% to 15% of the time) and to increase the time spent in safer longer headways (>1.2 s) by approximately 20% (from 57% to 65% of the time). The effect was similar for younger and older drivers, for male and female drivers, for urban and highway speeds, and for daytime and nighttime driving. An immediate application of these findings is to install headway feedback displays to drivers so that they may maintain safer headway distances than they do currently.

Acceleration↗

PubMedDate not supplied

Odds ratio, relative risk, absolute risk reduction, and the number needed to treat--which of these should we use?

INTRODUCTION: Statistical analyses of data and making sense of medical data have received much attention in the medical literature, but nevertheless have caused confusion among practitioners. Each researcher provides a different method for comparing treatments. For example, when the end point is binary, such as disease versus no disease, the common measures are odds ratios, relative risk, relative risk reduction, absolute risk reduction, and the number needed to treat. The question faced by the practitioner is then: Which one will help me in choosing the best treatment for my patient? METHODS: The purpose of this paper is to illustrate, using examples, how each measure is used, what it means, and what are its advantages and disadvantages. RESULTS: Some pairs of measures present equivalent information. Furthermore, it is shown that different measures result in different impressions. CONCLUSION: It is recommended that researchers report both a relative and an absolute measure and present these with appropriate confidence intervals.

Confidence Intervals↗

PubMedDate not supplied

Comparison of trabeculectomy with mitomycin C with or without phacoemulsification and lens implantation.

PURPOSE: To compare the results of combined trabeculectomy with phacoemulsification and posterior chamber intraocular lens (IOL) implantation to those of trabeculectomy alone using mitomycin C (MMC) application intraoperatively in all cases. PATIENTS AND METHODS: A retrospective comparative study of consecutive patients was conducted on two groups: 102 eyes of 90 patients studied in the combined procedure group, and 33 eyes of 30 patients in the trabeculectomy alone group. RESULTS: Both groups showed a significant decrease in IOP. The combined group had a change from 21.5+/-5.8 mm HG preoperative to 14.73+/-3.44 mm HG postoperative, P=0.0001; the trabeculectomy group changed from 24.2+/-7.5 mm HG preoperative to 12.46+/-3.86 mm HG postoperative, P=0.0001. This represents a 31.5% reduction in IOP in the combined group versus a 48.5% reduction in the trabeculectomy alone group (P=0.0001). The follow-up time was longer in the trabeculectomy group (trabeculectomy group, 22.6+/-13.3 months; combined group, 14.2+/-8.0 months), P=0.0014. There were 97 eyes in the combined group (95%) and 32 eyes (97%) in the trabeculectomy group that had an IOP of less than 20 mm HG at the end of follow up. Postoperatively, the two groups showed similar significant reductions in the number of antiglaucomatous medications used (combined group, 0.82+/-1.0 compared with 2.65+/-0.84 preoperatively, P=0.0001; trabeculectomy group, 0.76+/-1.2 compared with 2.7+/-0.95 preoperatively, P=0.0001). There were no cases of bleb leakage in the combined group and two cases (6%) in the trabeculectomy group. CONCLUSION: The reduction of IOP is significantly larger after trabeculectomy alone than after the combined procedure; however, the functional and anatomical results of the combined procedure of phacoemulsification, posterior chamber IOL implantation, and trabeculectomy with MMC application were as good as those of trabeculectomy alone with MMC.

Adult↗