Correlation between Vitamin D, homocysteine and brain-derived neurotrophic factor levels in patients with ischemic stroke.

OBJECTIVE: Ischemic stroke risk increase is in relation to low serum vitamin D levels in some studies; however, the uncertainty about its relationship to serum homocysteine and brain-derived neurotrophic factor (BDNF) concentration remains. The aim of this study is to investigate the correlation between vitamin D, homocysteine and BDNF levels in patients with acute stroke. PATIENTS AND METHODS: A total of 126 patients admitted to the emergency department with stroke and 64 healthy controls were included in this study. All patients received 150,000 U of vitamin D as part of a stroke treatment protocol during hospitalization. The patients were divided into two groups: the blood samples of the patients in the group-I (n=54) were taken at the time of admission to the hospital, and the samples of the patients in the group-II (n=72) were taken 24 hours after admission. Serum vitamin D, homocysteine, BDNF and routine biochemical analyses were performed from these samples. RESULTS: Compared to healthy controls, stroke patients had lower serum vitamin D (p<0.0001) and BDNF (p<0.0001) levels, and higher homocysteine levels (p<0.0001). It was found that the homocysteine level was constant and the BDNF level increased (p=0.01) 24 hours after the 150,000 U vitamin D supplementation. Furthermore, there was a negative significant correlation between vitamin D levels, homocysteine and BDNF in patients who had experienced a stroke. CONCLUSIONS: Vitamin D supplementation was used as a therapeutic agent in patients with acute ischemic stroke that affects homocysteine and BDNF levels. In this study, it was demonstrated for the first time that there is a correlation between serum vitamin D levels and BDNF levels in patients who have experienced a stroke.

[Corneal ring segments (INTACS) for the treatment of asymmetrical astigmatism of the keratoconus. Follow-up after 2 years]. / Anneaux intracornéens (INTACS) pour le traitement de l'astigmatisme asymétrique du kératocône. Recul de plus de deux ans.

OBJECTIVE: To evaluate the use of corneal ring segments (INTACS) for the treatment of asymmetrical astigmatism in keratoconus. MATERIAL AND METHODS: This prospective study involved nine eyes of seven patients who were operated on between December 1998 and June 2000. A case of keratoconus with opacified cornea was excluded from this study. The patients chosen were contact lens-intolerant. The surgical intervention was carried out under topical anesthesia. The INTACS (Addition Technology) corneal ring insert was inserted approximately 68% of the peripheral corneal depth and was centered to the cone of the cornea. RESULTS: No intraoperative complications occurred. We noted a flattening of the central cornea and a decrease in irregular astigmatism for all patients. Mean preoperative uncorrected visual acuity was less than 1/10. Postoperatively two eyes had an uncorrected visual acuity of 10/10, seven eyes showed an improvement from an uncorrected visual acuity of 2/10 to 7/10. CONCLUSION: We have observed that the flattening effect of INTACS inserts on the soft corneal keratoconic tissue and on the high astigmatic tissue seems greater than that produced in normal cornea. Implantation of INTACS resulted in a significant reduction in asymmetrical astigmatism of the keratoconus.

[Laser phacoemulsification with the Paradigm Photon Laser. Surgical technique and first results]. / Laser phaco par le Paradigm Photon Laser. Technique chirurgicale et premiers résultats.

Early clinical results and personal experience with a new technique in cataract surgery using Paradigm Photon Laser (neodymium Yag Laser) are reported. After the introduction of phako ultrasound in cataract surgery, Eichenbaum et al. examined the use of a laser system to improve cataract surgery. A phase I clinical trial was started in the USA in 1996 and a phase II clinical trial is currently ongoing. The Laser technique was performed as follows. A clear corneal incision measuring 2.8 mm, capsulorrhexis, hydrodissection and hydrodelineation of the nucleus and the epinucleus were performed first. A chopping instrument was then introduced by a second port to facilitate the laser procedure. Finally, the incision was enlarged to introduce the foldable IOL in the bag without suture. Eight eyes of six patients with a soft cataract were operated by Nd:YAG Laser, and followed for 6 to 10 months. No particular difficulty was observed concerning the technical procedure in comparison with the phako ultrasonic procedure. Photon laser may be an alternative treatment for softer cataracts with the following advantages: the vulnerability of the posterior capsule to the sharp needle of the phako ultrasonic instrument is eliminated using Photon Laser. There is no propensity for incisional burns nor ultrasonic vibration. However, additional progress is required for its application in hard cataract cases.