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Biomedical subjects

I Schipper

Publications and source records attributed to I Schipper.

At least 55 records · Page 3Linked to original sources
PubMed1995

Results of reshaping with the 193-nm excimer laser.

We report herein our experience with reshaping following primary photorefractive keratectomy (PRK). Reshaping was performed on 7 of 116 myopic eyes (6 patients) 6-12 months subsequent to initial treatment. We carried out reshaping on 5 eyes (4 patients) for either undercorrection or regression. The mean preoperative refraction was -6.9 D, and at 1 year postsurgery it was -0.3 D. At 6 months following reshaping, the mean refraction was -0.15 D and the average uncorrected visual acuity (VA) was 20/25. In one patient, retreatment was performed 6 months after initial PRK due to marked regression and deterioration of VA. At 9 months subsequent to reshaping, the VA had improved to 20/25 with spherical correction of -1.0 D. In another patient, the best corrected VA deterioriated from 20/40 (-13.5 D) to 20/80, with hyperopia of +3.5 D being combined with marked scarring. At 6 months following phototherapeutic keratectomy (PTK), the VA had improved to 20/50, with spherical correction of +1.0 D. In conclusion, these observations demonstrate that reshaping is a satisfactory mode of treatment in certain indications.

Adult↗
PubMed1995

Fitting contact lenses after excimer laser photorefractive keratectomy for myopia.

To compensate for undercorrection, regression, or irregular astigmatism, contact lenses are sometimes fit after excimer laser photorefractive keratectomy (PRK). We fit 13 eyes (eight patients) with aspheric rigid gas permeable (RGP) contact lenses following PRK. Patients were fit for various reasons, and they were all previous RGP contact lens wearers. Eight of 13 eyes could not be corrected with spectacles to the same acuity as before PRK. With RGP contact lenses, all patients were corrected to the same acuities as before PRK. The mean base curve of the preoperative RGP lenses was 7.98 +/- 0.36 mm (SD); the mean power was -5.92 D +/- 2.88 D (SD). Postoperative lenses had a mean base curve of 8.03 mm +/- 0.41 mm (SD) and mean power of -5.5 D +/- 3.08 D (SD). Fitting RGP lenses after PRK was uncomplicated, and all lenses were as well tolerated after PRK as they had been before the procedure.

Astigmatism↗
PubMed1995

Tapered transition zone and surface smoothing ameliorate the results of excimer-laser photorefractive keratectomy for myopia.

This report compares the results we obtained after photorefractive keratectomy (PRK) for myopia using different treatment modalities. PRK was performed on 35 eyes (group 2; mean refraction, -5.7 +/- 2.3 D) using a tapered transition zone (TTZ), smoothing of the corneal surface, and somewhat more steroids than usual. The results were compared with those obtained in another group of patients (group 1) with equally high myopia in whom these measures were not used. Quicker rehabilitation and stabilization of visual acuity (VA) and less regression were observed. An uncorrected VA of +/- 20/40 after 9 months was found in 94.4% of eyes in group 1 (P = 0.026). A refraction of +/- D after 9 months was found in 89% of eyes in group 2 and in only 58% of eyes in group 1 (P = 0.024). Haze reduction was quicker and stronger in group 2, and fewer patients in this group suffered loss of best corrected VA. The results of PRK of myopia can be ameliorated thanks to improved technique and increased experience.

Adult↗
PubMed1994

[Diplopia after retrobulbar anesthesia in cataract surgery--a case report].

A case report. A homolateral hypertrophia accompanied by diplopia occurred after retrobulbar anesthesia for cataract operation. In the course of the next few months a hypotrophia developed in the same eye. Two and a half years later a 5 mm recession of the inferior rectus muscle of the hypotrophic eye was performed under local anesthesia. The passive motility upwards improved already during the operation when the muscle was sectioned. After the operation there was a remarkable improvement of motility and field of vision. Conclusion. The cause of this diplopia is probably an injury of the inferior rectus muscle with a secondary contraction caused by the retrobulbar anesthesia. An injection along the inferior rectus muscle to achieve the retrobulbar anesthesia should be avoided.

Aged↗
PubMed1994

[2 years experience with the Excimer laser photorefractive keratectomy in myopia].

PATIENTS AND METHODS: Myopic PRK (Photorefractive Keratectomy) has been performed on 116 eyes (myopia of between -3.0 D and -25.5 D) in the eye clinic of Lucerne, since october 1990. 25 patients had both eyes treated, 7 eyes were retreated. RESULTS: Results are satisfactory for myopia of up to -10 D (-15 D); treatment of the higher myopia is problematic. CONCLUSION: Regression was the biggest problem in all patients, being the more pronounced the higher the ablation. Based on this experience recommendations for treatment are given.

Adult↗
PubMed1994

[Phototherapeutic keratectomy].

BACKGROUND: In the last few years the excimer laser has been increasingly used not only for refractive surgery but also for therapeutic purpose. We report about our two year experience with this form of therapy. PATIENTS AND METHODS: Phototherapeutic keratectomy (PTK) has been performed on 27 eyes of 25 patients. The following diseases have been treated: Recurrent erosions (14), 9 of them in connection with bullous keratopathy, persistent epithelial defects (4), corneal opacity (6), one of them due to macular dystrophy, limbal infiltrates (2) and pterygium (1). RESULTS: 3 of 4 patients with persistent epithelial defects and 92% of the recurrent erosions were treated successfully. Above all the treatment of recurrent erosions in connection with bullous keratopathy was very satisfactory. The patients with corneal opacity achieved a significant improvement of their visual acuity. CONCLUSION: The excimer laser is very suitable for therapy of different corneal surface pathologies. The possibility to treat painful bullous keratopathy is very encouraging.

Adult↗
PubMed1994

Correction of astigmatism with Excimer laser transverse keratectomy.

Transverse keratectomies with the Excimer laser were performed on seven eyes of 4 patients with a mean, naturally occurring astigmatism of 5.32D (SD 1.0), range 4.25 to 7.0D. One month later mean astigmatism was 3.46D (SD 1.35), 3 months later 3.8D (SD 1.35), rising to 4.3D (SD 1.6) after 6 months, and to 4.68 (SD 1.4) after 1 year. The refractive cylinder was reduced from a mean of 5.8D to 4.5D and the mean uncorrected visual acuity rose from 0.16 to 0.3. No serious complications occurred, and uncorrected visual acuity could be improved slightly. Excimer laser transverse keratectomy cannot be recommended as a good method to treat high degrees of naturally occurring astigmatism.

Adult↗
PubMed1994

Bubbles in the bleb--troubles in the bleb? Molteno implant and intraocular tamponade with silicone oil in an aphakic patient.

A 14-year-old aphakic girl who had had previous bilateral glaucoma surgery with a Molteno implant underwent pars plana vitrectomy and silicone-oil tamponade for proliferative-vitreoretinopathy retinal detachment in both eyes. The filtering bleb of the left eye was functional for 5 months before becoming available for histologic examination. We found numerous foreign-body granulomas coating the inner surface of the bleb, as well as intracellular and extracellular deposits of emulsified silicone oil in the wall of the bleb. In the fellow eye, the filtering bleb remained functional despite repeated vitreous surgery with silicone oil. Filtration in aphakic eyes with previous Molteno surgery and silicone-oil tamponade after vitrectomy may continue normally for a prolonged period of time, although emulsified oil droplets likely will have accumulated in the bleb and become incorporated in its fibrous capsule.

Adolescent↗
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↗
PubMed1993

Development of a human granulosa cell culture model with follicle stimulating hormone responsiveness.

In order to study the effects of follicle-stimulating hormone (FSH) on differentiation of granulosa cells, a well-defined and validated in-vitro culture system is indispensable. In this study, pooled follicular aspirates were stimulated in vitro with FSH and luteinizing hormone (LH) for 2, 4 and 6 days, either immediately after plating or after 7 days of preincubation. Cultures were assayed for progesterone and oestradiol production. Fresh cells displayed very high basal progesterone production which could be stimulated with LH but not FSH. After preincubation, addition of LH and FSH resulted in dose-dependent increases of progesterone and oestradiol. When cultured on human fibronectin-coated wells, similar basal but higher progesterone concentrations after stimulation were observed. In comparison with serum-free media, addition of Serum-Plus resulted in higher basal and stimulated progesterone concentration, possibly due to the presence of serum factors. This study demonstrates firstly that after 7 days preincubation, cultures gained responsiveness to FSH but remained responsive to LH during 4 days of stimulation. This suggests a persisting differentiated cell population in vitro. Secondly, the use of human fibronectin extracellular matrix and serum promotes steroid production, either due to factors promoting cell growth and function or to availability of steroid precursors. Therefore one has to be cautious with interpretation of data obtained from this widely used culture system, employing highly differentiated cells obtained after ovarian stimulation for in-vitro fertilization for study of local regulation of granulosa cell function.

Basal Metabolism↗
PubMed1992

[Bilateral optic neuropathy following amiodarone therapy].

The amiodarone-induced optic neuropathy seldom occurs and so far, only 17 cases have been reported. These results are summarized here and the differences between them and the ischemic optic neuropathy are pointed out. We report on a 62-years-old patient who, when treated with amiodarone, developed an optic atrophy with slightly decreased visual acuity and severe visual field defects of the left eye. On the right eye we discovered shortly after discontinuing the amiodarone therapy, how, a mild swelling of the optic disc changed to an optic atrophy with analogous, irreversible changes of visual acuity and visual fields.

Amiodarone↗
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

[Valsalva's maneuver: not always benign].

Five cases are being discussed here, where an apparently harmless Valsalva manoeuvre caused different clinical manifestations in the eyes: a large central preretinal hemorrhage, diffuse retinal hemorrhages, a Purtscher retinopathy and a blindness associated with a haematoma of the upper and lower lid of the right eye, probably caused by bleeding in the sheeths of the optic nerve. It is important to note that a Valsalva manoeuvre can cause different manifestations in the eye, apart from the known small premacular haemorrhage. Since the Valsalva manoeuvre is a common phenomenon, one should keep it in mind when observing unclear ocular findings.

Adult↗
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

[Spot-like to reticular pigment displacement in a patient with pseudoxanthoma elasticum (Grönblad-Strandberg syndrome)].

The authors report a rare observation of leopard spot-like and reticular pigmentary patterns in a patient with pseudoxanthoma elasticum (PXE). Characteristic fundus changes associated with PXE have been described as angioid streaks, subretinal neovascularization membranes, peau d'orange, focal retinal pigment epithelium atrophy (salmon spots), drusen, and optic nerve head drusen. The new manifestation of PXE in the fundus of the patient described here is a random scattering of small, dark brown pigment dots throughout the macula and around the disk. These clumps may flow into one another or join together like a string of pearls. These changes are rare and should be distinguished from the others mentioned above. To the authors' knowledge no more than ten cases have been reported in the literature so far.

Angioid Streaks↗