Fortschritte der Ophthalmologie : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft最新文献

Corneal wound healing was studied after photoablation with an excimer laser (193 nm, 43 pulses at 180 mJ/cm2 [symbol: see text] 11 microns ablation depth, optical zone 2.0 mm) and with an erbium-YAG laser (2.94 microns, 5 pulses at 2.5 J/cm2 [symbol: see text] 50 microns ablation depth, optical zone 1.6 mm). The corneas of marmosets (Callithrix jacchus) were prepared 5 and 10 days and 4 and 25 weeks after photoablation. The sections were investigated by conventional light microscopy or exposed to antibodies against collagen types I, III, IV, VII and laminin and stained by indirect immunofluorescence. Macroscopically, the time-course of wound healing was comparable to that seen, after laser keratomileusis for correction of myopia in humans (epithelium closure after 24-48 h, subepithelial haze: erbium-YAG less than or equal to excimer). Histologically the time-course of wound healing could be schematically divided into three phases: (1) epithelial hyperplasia, inhomogeneous new synthesis of collagen fibrils subepithelially; (2) reorganization of the epithelium, hyperplasia of keratocytes, incipient reorganization of the collagen fibrils, increase in subepithelial haze; (3) reorganization of the collagen fibrils, decrease in subepithelial haze. The distribution of collagen type VII during the corneal wound healing suggests that the subepithelial haze observed during the healing process after laser keratomileusis for correction of myopia is based on the anchoring fibrils of the basement membrane.

We describe the long-term results after treatment of 68 eyes in advanced stages of proliferative vitreoretinopathy with vitrectomy, daunomycin perfusion, and silicone oil injection. Six reoperations were performed. After 18 months, 73% of the eyes showed no signs of retinal detachment and 89% had a visual acuity greater than 20/800. These results are better than those reported in previously published studies. Whether this improvement is due to the daunomycin treatment or to more aggressive surgical techniques, such as retinotomies, remains to be answered by a randomized trial.

MK-417 (sezolamide) is a topically active carbonic anhydrase inhibitor. The effect of additional treatment with sezolamide 1.8% twice daily to patient already receiving timolol 0.5% twice daily was investigated. For this purpose, 12-h diurnal curves were used in a double-masked, randomized, placebo-controlled, parallel study in 36 patients with bilateral primary open angle glaucoma or ocular hypertension who during beta blocker therapy had intraocular pressures (IOP) greater than or equal to 22 mmHg. For 15 days patients received sezolamide or placebo 10 min after 0.5% timolol given at 8 a.m. and 8 p.m. On treatment day 15, this addition of sezolamide twice daily induced a further mean decrease in IOP of approximately 4 mm Hg (about 15%) at 1, 2 and 4 h and of approximately 2-3 mm Hg at 0, 6, 8, 10 and 12 h after drug administration, thus demonstrating a partial additive effect of sezolamide and timolol. Thus, sezolamide may be a useful addition to the treatment of glaucoma in patients not adequately controlled by beta blocker therapy.

This clinical study was designed to evaluate the difference between preoperative treatment of the conjunctiva with either gentamicin eyedrops or a half-strength povidone iodine solution. We treated 50 eyes of 50 patients who came for cataract surgery and showed bacterial growth in the first conjunctival smear with gentamicin eyedrops at 1-h intervals for at least 10 h. The second smear was taken the next day. At the same time, half strength povidone-iodine solution on was applied to the follow-eye. After 2 min the second smear was taken. With both methods a significant reduction of bacterial growth was achieved. The average number of colonies decreased from 1620 to 63 after treatment with gentamicin and from 1338 to 214 after treatment with povidone iodine. There was no significant difference between the two methods. No allergic reactions or corneal haze after application of povidone iodine were observed.

Twenty patients undergoing surgery for correction of strabismus under general anesthesia were randomly selected to receive conjunctival application of 100 microliters (20 micrograms) adrenaline in both eyes or in neither (controls). A further 20 patients undergoing cataract surgery with local anesthesia were randomly selected to receive 1 ml adrenaline 1:10 000 (100 micrograms) or 1 ml balanced salt solution (controls) in the anterior chamber. Adrenaline in plasma was measured in six time points within 15 min (correction of strabismus) or at seven within 30 min (cataract surgery). Plasma levels of adrenaline, mean arterial pressure, and heart rate were comparable in treatment groups and controls. No severe arrhythmias were observed. Neither conjunctival application of 20 micrograms adrenaline or instillation of 100 micrograms adrenaline into the anterior chamber increases adrenaline levels in plasma, and there is no reason to suspect cardiovascular interactions.

Toxoplasmosis-retinochorioiditis is the second most frequent opportunistic infection of the eye among our series of AIDS patients. Between 1985 and 1990 we diagnosed 7 cases in 261 AIDS patients (Walter Reed classification 6); prevalence = 2.7%). The incidence has been increasing over the years. In four cases, toxoplasmosis was restricted to the eye, in three cases, ocular disease occurred combined with toxoplasmosis of the central nervous system. Since serological findings are not very reliable in AIDS-patients, the most important element in the differential diagnosis against retinitis of different etiology is ophthalmoscopy. There are a number of findings which allow differentiation of toxoplasmosis from other forms of retinitis, especially cytomegalovirus retinitis. Toxoplasmosis-retinitis was stopped in all cases by administering a specific therapy of pyrimethamine combined with clindamycin, a sulfonamide or spiramycin. Stable scar formation was achieved after 2-3 weeks therapy. Subsequent maintenance therapy with Fansidar (pyrimethamine + sulfadoxine) protected 4/4 patients from a relapse, while maintenance therapy with pyrimethamine alone allowed a relapse in 1/2 patients.

In six eyes we found typical signs that could serve as criteria for the differentiation of ischemic from non-ischemic retinal branch vein occlusion. Perimetry showed a mean defect (in the affected area) of more than 10 dB in eyes with defects in the retinal nerve fiber layer in contrast with 5 dB on one eye without nerve fiber defects. Secondly, fluorescein angiography showed ischemic areas in all eyes examined with localized defects in the photographs of the retinal nerve fiber layer. Damage of the retinal nerve fiber layer was observed before capillary obliteration could be detected by fluorescein angiography. Thirdly, semiquantitative optic disc morphometry demonstrated that using the difference between pallor and excavation as the only sign in ascending optic atrophy is not always useful. Fourthly, photography of the retinal nerve fiber layer showed that there is no correlation between the extension of the ischemic area and the sector angle of the defect of the retinal nerve fiber layer. Photography of the retinal nerve fiber layer can differentiative ischemic from non-ischemic retinal branch vein occlusion because of the qualitative detection of localized retinal nerve fiber layer defects. Consequently, this method is not only of great clinical importance for the diagnosis of different optic lesions, but is also useful for the prognosis and management of occlusion of the retinal branch vein.

Viscoelastic substances in correlation with intraocular hypotony have gained great significance in low-irritation cataract surgery within the last few years. The differences in their chemical properties, and thus in their effect on the eye, formed the grounds for a controlled clinical study comparing sodium hyaluronic acid, representing the group of glucosamine glykanes, and hydroxypropylmethyl cellulose (HPMC), representing the group of cellulose ethers. Two hundred cataract patients, excluding those suffering from diabetes mellitus, glaucoma and severe corneal damage, were examined on the 1st, 2nd and 5th postoperative day, as well as 4 weeks postoperatively. Statistically, no significant differences were found as regards IOP and postoperative anterior chamber irritation. From the economical point of view, methocel (HPMC) should be preferred to sodium hyaluronic acid in routine cataract surgery due to the lower costs.

In this study we tried to find out if the hemodynamic results could help us explain why the visual situation after retinal surgery often becomes unsatisfactory despite good anatomical results. Using Ulrich's methods (oculo-oscillodynamography), we measured the hemodynamic parameters-especially ciliary perfusion pressure and the volume of blood flow--in 40 patients after retinal surgery. One of our results is remarkable: there is a direct relationship between the amount of scleral buckling and a disturbance in the hemodynamic parameters. Otherwise, we found that hemodynamic disturbances after vitreous surgery (vitrectomy, silicone oil implant or gas) are less dramatic than after buckling methods or in connection with them. Also, the hemodynamic disturbance begins before retinal surgery, obviously according to the stage of ablation: with or without macular involvement and irrespective of the time of retinal detachment. After all we have demonstrated in this study, we have reason to believe that a disharmony in the ocular hemodynamics causes disappointing visual results, often seen after retinal surgery.