Patients with the myopathic form of carnitine palmitoyltransferase II (CPT II) deficiency typically experience muscle pain, cramps, and myoglobinuria during prolonged exercise. It has been suggested that carriers of CPT2 gene mutations also may have milder clinical symptoms, but fatty acid oxidation (FAO) has never been investigated in vivo in this group. We studied fuel utilization by indirect calorimetry and stable isotope methodology in four patients with CPT II deficiency, three subjects who carried one CPT2 gene mutation, and five healthy control subjects. Cycle exercise at a constant workload of 50% of maximal oxygen uptake capacity was used to facilitate FAO. We found that in vivo oxidation of long-chain fatty acids was normal at rest but severely impaired during prolonged, low-intensity exercise in patients with CPT II deficiency, and that two of the single CPT2 gene mutation carriers, who displayed symptoms of CPT II deficiency, had an FAO comparable with the patients. These results indicate that residual CPT II activity is sufficient to maintain long-chain FAO at rest in CPT II deficiency but not to increase FAO during exercise. The findings also suggest that single CPT2 gene mutations may exert a dominant-negative effect on the tetrameric CPT II protein. Neurol 2005;57:60 -66 Ann

It is generally believed that a diet high in carbohydrate improves exercise tolerance in patients with carnitine palmitoyltransferase II (CPT II) deficiency, but it has never been systematically investigated. The authors investigated the effect of a high- vs low-carbohydrate diet on exercise tolerance in four patients with CPT II, who cycled at a constant workload of 50% of VO2max. Exercise tolerance, assessed by exercise duration and perceived exertion, improved on the carbohydrate-rich diet.

BRVO in pig eyes examined by mfERG is a promising model for testing new treatment strategies in retinal ischemia. The local effects of BRVO are detectable on the mfERG and can be altered by dorzolamide. The decreased iN1 amplitudes caused by dorzolamide in healthy eyes were not seen in BRVO eyes possibly because of an increase in preretinal oxygen tension and improved function of the ischemic retina counteracting the effect of inner retinal acidification.

The functional consequence of long-term retinal detachment in the porcine model is examined by multifocal electroretinography (mfERG). Retinal detachment (RD) in humans leaves permanent visual impairment, despite anatomical successful reattachment surgery. To improve treatment, adjuvant pharmaceutical therapy is needed, and can only be tested in a suitable animal model. The porcine model is promising and the mfERG is well validated in this model. RD was induced in 18 pigs by vitrectomy and healon injection of various concentrations. Preoperatively and 6 weeks postoperatively eight animals were examined by mfERG. The major component P1 was analyzed statistically. Indirect ophthalmoscopy and bilateral color fundus photography (FP) were performed. Selected animals underwent high-resolution optical coherence tomography (OCT). Examination by ophthalmoscopy and FP showed that the RDs remained detached for the 6 weeks of follow-up. The P1 amplitude of the mfERG did not differ significantly between the detached areas, the surrounding attached areas, and the healthy eye (p = 0.25). Similarly, P1 implicit time did not differ between the areas (p = 0.85). The lack of functional consequences of long-term RD makes the porcine model unsuitable for examining adjuvant pharmaceutical RD treatment. Future studies should focus on foveated primates.

Subretinal ICG induces histological and functional damage to the retina, suggesting that ICG should be used with caution in macular hole surgery, where subretinal migration can occur. In contrast, BBG and TA appear safe after subretinal injection.

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ObjectiveFemtosecond laser-assisted cataract surgery (FLACS) decreases the use of energy and provides a more precise capsulorhexis compared with conventional phaco surgery (CPS). The purpose of this study was to examine if the lower energy use in FLACS caused less endothelial cell loss compared with CPS and if there was a difference in refractive predictability between CPS and FLACS.Methods and analysisThis was a randomised controlled study of 96 patients with a 6-month follow-up comparing one eye surgery by FLACS and the contralateral eye operated by CPS (divide and conquer technique). Both eyes had intraocular aspheric lenses implanted. Uncorrected distance visual acuity, corrected distance visual acuity (CDVA), central corneal endothelial cell count and hexagonality (non-contact endothelial cell microscope) were assessed preoperatively at 40 and at 180 days postoperatively.ResultsThe mean phaco energies were 6.55 (95% CI 5.43 to 7.66) and 9.77 (95% CI 8.55 to 10.95) U/S (p<0.0001) by FLACS and CPS, respectively. At day 40, the mean endothelial cell loss (ECL) was 344 cells/mm2 (95% CI 245 to 443) by FLACS (12.89%) and 497 cells/mm2 (95% CI 380 to 614) by CPS (18.19%) (p=0.027). At day 180, ECL was 362 cells/mm2 (95% CI 275 to 450) in FLACS (13.56%) and 465 cells/mm2 (95% CI 377 to 554) in CPS (17.03%) (p=0.036).The mean absolute difference from the attempted refraction was 0.43 (95% CI 0.36 to 0.51) dioptres (D) at day 40 and 0.46 D (95% CI 0.39 to 0.53) at day 180 by FLACS compared with 0.43 D (95% CI 0.36 to 0.51) at day 40 (p=0.95) and 0.46 D (95% CI 0.37 to 0.52) at day 180 (p=0.91) with CPS.ConclusionECL was significantly lower in FLACS compared with CPS at both day 40 and day 180. ECL was correlated to the energy used. We found no difference in refractive predictability or CDVA between the groups.

Sequelae are common after bicanalicular lacerations. The use of one or two monostents to the nose appears to be a reasonable alternative to the traditional use of one bicanalicular stent.