Search PubMed⌕ Search

Biomedical subjects

P Senn

Publications and source records attributed to P Senn.

27 records · Page 2Linked to original sources
PubMed1993

[Brief narcosis with propofol/ketamine for administering retrobulbar anesthesia].

BACKGROUND: Eye surgery is performed under local anesthesia in more than 90% of the cases. While injecting the local anesthetics a deep sedation is desired. During surgery however the patient should be cooperative, such as to avoid inadvertent movements. We routinely perform local anesthesia (retrobulbar injection and van Lint block) under intravenous anesthesia with propofol (Disoprivan) and ketamine (Ketalar, Ketanest). PATIENTS AND METHODS: To control safety and efficacy of this method a prospective study was performed including 100 consecutive patients. The results were to be compared with an earlier study where 35 Patients received midazolam (Dormicum) and alfentanil (Rapifen) as sedation. The actual protocol included the following points: 1. Personal judgement of the patient. 2. Conditions to perform the retrobulbar injection, 3. Intraoperative conditions and additional sedation, 4. Pulse, blood pressure and blood oxygen concentration, 5. Complications RESULTS: > 95% of the patients had a total amnesia of the injection of local anesthetics. Retrobulbar injection is comfortable (96%), but may be difficult in patients with a narrow orbit and exotropia (4%). Intraoperative conditions were noted as good in 97%. Additional sedation during surgery was necessary in 3%. Blood pressure and pulse remained stable. Blood oxygen concentration showed a tendency to sink during intravenous anesthesia. This could be managed easily by additional oxygen via face mask if necessary. Postoperative emesis was noted in 3%. No further ocular complications occurred that might be related to the anesthetic management. In an earlier study including 35 Patients under comparable conditions we used midazolam and alfentanil for sedation. The results were similar. Midazolam and alfentanil were then used in over 2000 operations. Often the patients were deeply sedated and asleep during surgery which meant a potential risk of a sudden awakening and moving the head inadvertently. Occasionally paradoxical reactions occurred after midazolam. CONCLUSIONS: Using propofol and ketamine while performing the local anesthesia the patients are awake but relaxed and cooperative during surgery. This method has now been used routinely in over 1000 cases. It has proved to be clinically safe and efficient. It offers the surgeon good working conditions and is well tolerated by the patients, reducing their preoperative and perioperative anxieties.

Adult↗
PubMed1992

[The Excimer laser. I. The Lucerne evaluation procedure for Excimer therapy].

The Excimer laser has been available for clinical applications in the Lucerne Eye Hospital since September 1990. Excimer laser keratectomy as a refractive therapy option is meeting with widespread interest among patients. As this is an invasive method whose complications cannot be neglected and for which long-term experience is so far lacking, this interest has to be balanced by extremely strict and responsible diagnosis by those offering the therapy. The authors present their evaluation concept here. The figures below document the reticence exercised in diagnosis: 1100 information leaflets dispatched are contrasted in the final analysis with only 34 laser treatments in a period of 10 months. 50 of the 200 patients admitted (referred by specialists) for preliminary examinations were definitively excluded from treatment in Lucerne as early as the administrative stage, and 61 during the clinical evaluation proper.

Cornea↗
PubMed1992

[The Excimer laser. II. Initial experiences with the Excimer laser in Lucerne].

In the period between September 1990 and July 1991, 35 patients (46 eyes) were treated with the Excimer Laser. In 25 patients (34 eyes), a Myopia-Laser-Shaping was performed, one patient was treated for both myopia and astigmatism. In eight patients (10 eyes) correction of astigmatism was carried out. Two patients with recurrent erosions and one patient with superficial scarring of the cornea were treated. The authors review their initial experience with the Excimer Laser. The decision to initiate treatment must not be undertaken lightly, because the possibility of serious complications may not be neglected. This method shows promise in selected patients with light to medium degrees of myopia. In cases of severe myopia, our experience is encouraging. Subjectively, the patients are satisfied with the results, which do not fall short of their expectations. Further research and clinical experience in this area is urgently required.

Astigmatism↗
PubMed1991

[Practical experiences in conversion to the wide angle observation systems for vitreous surgery BIOM, SDI, VPF].

The wide-angle observation system for vitreous surgery introduced by Spitznas und Reiner has the following advantages: Wide angle of view. Large depth of field. Good view to the periphery even with narrow pupil. Easy gas fluid exchange in a phacic eye. Free mobility of the eye when working in the periphery. Changing from the conventional vitrectomy lens system to the BIOM an experienced surgeon is familiar with the new system in a very short time.

Equipment Design↗
PubMed1991

[Pars plana vitrectomy and cerclage after successful glaucoma operation with Molteno implant].

A single or double plate Molteno Implant may control IOP in otherwise desperate cases. Fibrosis of the filtration bleb will lead to failure. We report about 4 patients (age 12 to 77 years--3 neovascular glaucoma, 1 with postinflammatory goniosynechia) who had good IOP after the implantation of a Molteno device. 10 to 26 weeks (mean 18.25) after glaucoma surgery we performed a pars plana vitrectomy because of different reasons: proliferative diabetic retinopathy, proliferative retinopathy due to central venous occlusion, ciliovitreal block mechanism, PVR D3. One aphakic eye was treated with silicone oil and an encircling band. 19 to 30 weeks after posterior segment surgery (mean 24.5) IOP remained controlled. We describe the technique of pars plana approach and putting an encircling band without destroying the preformed filtration bleb. Encircling techniques, pars plana vitrectomy and silicone oil in aphacic eyes seem to bee possible without loss of the filtration effect of the Molteno operation.

Adolescent↗
PubMed1990

[Nd:YAG laser synechiolysis in glaucoma due to iridocorneal angle synechiae].

Seven patients with chronic angle-closure glaucoma and medically uncontrollable intraocular pressure were treated with the Q-switched Nd:YAG laser. Goniosynechiolysis was achieved at least partially. Follow-up time was 6-17 months. By means of additional monotherapy with a local beta-blocking agent where necessary, intraocular pressure was regulated to below 21 mm Hg in 5 of 7 patients. There were no severe complications. In selected cases Nd:YAG goniosynechiolysis may represent an effective means of lowering intraocular pressure.

Acetazolamide↗
PubMed1990

[Reduced visual function in relation to compensation questions].

In cases of visual impairment due to an accident it is the ophthalmologist's task to assess the functional loss. For the purposes of legal equality norms have been established for functional loss. Differences in the assessment of disability and loss of integrity in various countries are discussed.

Blindness↗
PubMedDate not supplied

Combined pars plana vitrectomy, phacoemulsification, and intraocular lens implantation in the capsular bag: a comparison to vitrectomy and subsequent cataract surgery as a two-step procedure.

BACKGROUND AND OBJECTIVE: To evaluate the effectiveness and safety of combined surgery. PATIENTS AND METHODS: Combined surgery (CS) consisting of pars plana vitrectomy (PPV), phacoemulsification, and implantation of a posterior chamber intraocular lens (PC IOL) in the capsular bag was performed on 26 patients. Another 26 had phacoemulsification with PC IOL insertion one to 84 months (mean 17.3) after PPV (sequential surgery, SS). Mean follow-up was 21.9 months after CS and 19.5 months after the cataract surgery in the SS group. The data were analyzed in a prospective, nonrandomized fashion. RESULTS: Visual acuity and refraction, astigmatism, accuracy of biometry, intraocular pressure, intraoperative, postoperative and long-term complications, and medical treatment were comparable in the two groups. Among the four uveitis patients in each group, transient fibrin formation was more frequent with CS (100%) than with SS (25%). The advantages of CS are that only one operation is needed, intraoperative working conditions are good, macular recovery is not masked by postvitrectomy cataract formation, and ideal lens centration is achievable. Potential disadvantages of CS include a longer operative time and increased technical demand, shrinkage of the anterior capsular opening, which may interfere with fundus view, and increased inflammation may be seen in patients with preexisting uveitis. CONCLUSION: Combined surgery in selected patients is a safe and effective approach, and outcomes are comparable to sequential surgery.

Adult↗