Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0026827 (hypotonia)
 5,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sulfur hexafluoride (SF6) is used for internal tamponade during retinal detachment surgery. It is usually injected into the eye by a plastic syringe either with a sharp needle or by using the infusion system during pars plana vitrectomy. Although several suggestions exist for the appropriate application of intraocular SF6 and other perfluocarbons, a sudden postoperative rise in tension or hypotonia has been observed repeatedly. We simulated the preparation and application of mixtures of sulfur hexafluoride and air and analyzed possible mistakes. SF6 was quantitatively analyzed by infrared spectroscopy. SF6 does not rapidly diffuse out of capped plastic syringes made of polypropylene, as commonly employed in the Federal Republic of Germany. SF6 and air mix completely during aspiration. If the volume of microporefilters or tubes being used for preparation and instillation of mixtures of SF6 and air is ignored, this may result in a 20% deviation in SF6 concentration. Silicone tubes, which are widely used for the influsion during pars plana vitrectomy, are not recommended for the application of SF6. SF6 and fluorcarbones diffuse through silicone tubes and absorb and desorbe in the tube. Infusion lines made of polyethylene or polyvinylchloride, e.g. butterflies, should be preferred.
 ...
PMID:[Dosage errors and their prevention in intraocular SF6 injection for endotamponade in pneumatic retinopexy and after vitrectomy]. 179 81

At the Second Ophthalmological Clinic in Prague the authors operated between January 1991 and November 1993 50 patients, 33 men and 17 women. The mean age of the patients was 43.6 years, the minimum observation period 5 months. In all patients pars plana vitrectomy was performed (PPV) and at the end of the operation or subsequently into the vitreous space the expansive gas SF6 (hexafluorosulphide) or C3F8 (perfluoropropane) was insufflated. In all instances the authors indicated the expansive gas for treatment or prevention of retinal detachment and with regard to this they divided the patients into two groups: 1. From the total number of 50 patients the authors operated in the first group 31 patients with complicated retinal detachment (RD). In 17 patient RD with large postequatorial tears and traces of blood in the vitreous space were involved. In 7 patients the cause of RD was a severe eye injury. In five patients the authors found a macular opening, in one patient a large postequatorial tear in the temporal half and in one patient a circumscribed tractional RD associated with diabetic proliferative retinopathy was involved. 2. In the second group of 19 patients the gas was used as prevention of RD. In 5 patients after transvitreal extraction of a foreign intraocular body with suspected or obvious retinal defect. In two patients after extraction of a posterior lenticular luxation following severe contusion of the eye. In the remaining 12 patients the expansive gas was used after removal of silicone oil (SO) and the gas was used at the same time to prevent hypotonia of the eye. Anatomical results of surgery. 1. In the group of 31 patients with complicated RD after PPV and gas insufflation the retina adhered anatomically in 23 patients (74%). In the group with PVR C1-C3 in 13 patients after gas insufflation the retina became attached in 10 patients (76.9%). In one of these patients after three months accentuated cerclage was performed because of a new fissure. 2. In the group of 19 patients where gas was used for preventive reasons the retina became detached only after removal of SO in 5 of 12 patients (42%). Functional results of operation. To assess final vision the authors evaluated in the first group a total of 39 patients only after gas insufflation and in the second group another 11 patients after reoperation with implantation of SO.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:[Personal experience with expanding gases in pars plana vitrectomy]. 780 15

The purpose of this article is to report the surgical treatment of two patients. After the filtering surgery a dehiscence of the conjunctiva emerged and was followed by an extreme hypotony of the eyeball and an extensive uveal effusion. The first patient, 82 years old lady, was treated with the diagnosis of chronic open angle glaucoma for 25 years. The right eye with an absolute glaucoma, the left eye had normal intraocular pressure (IOP) and was after a combined filtering surgical procedure with phacoemulsification and posterior chamber intraocular lens (PC IOL) implantation in 1998. In autumn 2000, the patient suffered conjunctivitis, and the prominent filtering bleb was damaged due to frequent rubbing of the eye because of itching. Severe hypotony of the eyeball with secondary uveal effusion followed. Considering the age of the patient and the only functional eye, an extreme surgery was indicated: PC IOL explantation (removal), pars plana vitrectomy (ppV) with silicone oil implantation. After the surgery the eyeball was anatomically stabilized and the VA (visual acuity) improved from initial uncertain light perception to 0.08 (1/12 or 3/36) and certain light perception. The second patient, 35 years old man suffered in 1995 a serious penetrating injury with an intraocular foreign body of the right globe. During the following five years the patient underwent in altogether six intraocular surgeries due to posttraumatic cataract and rhegmatogenous and tractional detachment of the retina. In the year 2000, trabeculectomy due to secondary glaucoma was indicated and 8 months later, on patients demand an anterior chamber intraocular lens (AC IOL) was implanted. During the first week after the surgery severe hypotonia of the globe and secondary uveal effusion caused by conjunctival dehiscence in the upper nasal quadrant of the eyeball developed. Because of complicated ocular history of the patient who underwent on the whole eight eye surgeries a relative minimal procedure was indicated: AC IOL removal and insufflation of 1 ml of 100% hexafluorosulfide (SF6) expansive gas into the anterior chamber and vitreous cavity. The globe was stabilized and the VA (visual acuity) improved from initial uncertain light perception to 0.25 (6/24 or 20/80) with certain light perception.
 ...
PMID:[Treatment of uveal effusion syndrome after filtering surgery (2 case reports)]. 1518 52