[Femtosecond laser ablation and scanning microscopy of the internal retinal limiting membrane: an experimental study].

The investigation was undertaken to study whether femtosecond laser ablation and microscopy might be used in the internal retinal borderline membrane. Ablation of internal limiting membrane preparations removed using or not using indocyanine green was made by a low-energy femtosecond laser. Examination of the preparations by laser and electron microscopy revealed precision laser cuts of the internal retinal borderline membrane. The use of indocyanine green during laser ablation reduced laser irradiation parameters as compared to the dye not being applied. Low-energy femtosecond lasers enable precision contactless ablation of the internal borderline membrane to be carried out without collateral damage to the adjacent tissue. The parameters of laser impulses, particularly low ones used in the ablation of indocyanine green-stained preparations, prove the photosensitizing effect of the dye.

[Development of visual acuity and refraction in deep lamellar and penetrating keratoplasty (KPL)]. / Entwicklung der Sehschärfe und der Refraktion bei tief lamellierender und penetrierender Keratoplastik (KPL).

BACKGROUND: Deep lamellar KPL can be considered as an alternative for penetrating KPL in pathologies of corneal stroma, because there is no risk of decompensation of the endothelium or corneal rejection. Nevertheless, it is well know in lamellar keratoplasty that scars may occur in the interface which can limit the final visual acuity. In a retrospective study we compared the postoperative development of visual acuity and refractive values in deep lamellar keratoplasty with a penetrating procedure. PATIENTS AND METHODS: 16 consecutive patients (mean age 48 years) with corneal stroma pathologies such as corneal ulcer, alkali burn and keratoconus underwent deep lamellar KPL. The control group consisted of 38 patients (mean age 42 years) with keratoconus who received a penetrating keratoplasty. Visual acuity and subjective spherical and cylindrical values of the refraction were evaluated preoperatively and after 6 weeks, 6 months and 1 year. RESULTS: The mean postoperative visual acuity (VA), spherical (SV) and cylindrical (CV) values of the deep lamellar group (results of the control group in brackets) were at 6 weeks VA = 0.24 +/- 0.24 (0.37 +/- 0.23), SV = 0.325 +/- 5.3 dpt, CV = - 1.66 +/- 0.67 dpt (- 3.08 +/- 1.93 dpt), after 6 months VA = 0.38 +/- 0.28 (0.53 +/- 0.31), SV = - 3.0 +/- 4.42 dpt (0.33 +/- 1.93 dpt), CV = - 2.57 +/- 2.03 dpt (- 2.35 +/- 1.32 dpt) and after 1 year VA = 0.41 +/- 0.27 (0.57 +/- 0.26), SV = - 2.57 +/- 4.62 dpt (0.17 +/- 3.98 dpt), CV = - 2.75 +/- 1.25 dpt (- 0.34 +/- 1.86 dpt). There was no significant difference in all the parameters between the two groups. CONCLUSIONS: As the good functional results of deep lamellar KPL are comparable to those of penetration KPL and the risk of endothelial decompensation or rejection is lower in a lamellar procedure, we suggest the use of a deep lamellar KPL in patients with an intact endothelium.

[Does acetylsalicylic acid have a negative influence on photodynamic therapy?]. / Wirkt sich Acetylsalicylsäure negativ auf die photodynamische Therapie aus?

BACKGROUND: Non-thermal photodynamic therapy (PDT) is presently being used for the treatment of certain forms of age-related macular degeneration (AMD). This therapy results in selective occlusion of newly growing vessels. Due to this effectiveness of PDT the question came up whether inhibitors of platelet aggregation have an influence on PDT. PATIENTS AND METHODS: Our retrospective study included 60 patients with mainly classic subfoveal choroidal neovascularizations (CNV) due to AMD. All patients were treated by PDT. Thirty patients took acetylsalicylic acid (aspirin) because of their general disease before and during treatment. In the control group none of the patients took acetylsalicylic acid. RESULTS: Best corrected visual acuity and measured dimension of the choroidal neovascularization showed before beginning PDT no statistically significant difference (visual acuity p=0.676; dimension of CNV p=0.678). Also no significant difference existed between visual acuity (p=0.412; p=0.226; p=0.969) and CNV (p=0.871; p=0.245; p=0.323) at the follow-up examination. CONCLUSION: Our study has shown that acetylsalicylic acid does not have any effect on PDT treatment.

Medium term results in keratoprostheses with biocompatible and biological haptic.

PURPOSE: Corneal grafts or limbal stem cell transplantation are often unsuccessful in patients with severe ocular surface disorders such as severe dry eye syndrome, symblepharon or diffuse vascularisation. In those patients, a keratoprosthesis (KPro) may be an alternative for the recovery of vision. Various KPro differ from each other in the material of the haptic that supports the optic cylinder. The haptic may be made of biocompatible or biological material such as tibia bone (TKPro) or dentine and alveolar bone (osteo-odonto-keratoprosthesis, OOKP). On the basis of our experience, we wanted to comment on the value of different KPro. METHODS: Over the last 10 years we have implanted a total of 35 KPro, 29 with biological haptic (25 OOKP and four TKPro), and six KPro with biocompatible haptic (one Legais KPro, five Pintucci KPro). A follow up examination was carried out approximately every6 months. RESULTS: The patients gained a visual acuity of > or =0.9 in 20.6%, of > or =0.5 in 52.9%, of > or =0.2 in 61.8% and a significant improvement in visual acuity in 76.5%, respectively. There was no significant difference between the various types of KPro concerning the best postoperative visual acuity. All patients showing poor improvement had a pre-existing end stage secondary glaucoma or other retinal damage. The median follow-up was 2.9 years (maximum 8) for OOKP, 1 year for TKPro, 1 year (maximum 2) for Pintucci Kpro and 6 month for Legeais KPro. During this period, only one of the KPro with biological haptic was lost (one TKPro after 1 year), compared with four out of six of the KPro with biocompatible haptic (P<0.0001). CONCLUSIONS: Fixation of the KPro by a root of the patient s own tooth (OOKP) leads to the best results in the long-term follow up, as our results as well as the literature demonstrate. As long as a KPro is in place, the visual acuity is as good as the retinal function. For the ranking of different types of KPro, the percentage and the duration of the anatomic success are most important. The comparability of the various KPro results may be limited, since the patients were not randomised and the four groups differ in number.

[The Ahmed glaucoma valve. Medium term results]. / Die "Ahmed glaucoma valve" Mittelfristige Ergebnisse.

BACKGROUND: In complicated glaucoma, when classical filtrating surgery would be ineffective, aqueous shunts may be used. Complications due to hypotonia are reduced by valved systems, such as the Ahmed glaucoma valve (AGV). METHOD: In a retrospective case control study, 28 patients with complicated glaucoma were included. In addition to the clinical examination, we examined the size and function of the filtering area using ultrasound. RESULTS: The medium term follow-up was 25+/-16 months, the preoperative intraocular pressure (IOP) 35.5 mmHg+/-10.3 while 17 eyes were pseudophakic and nine aphakic. In the first weeks after AGV implantation, the mean IOP was 6.3+/-2.5 mmHg. In nine eyes, the pressure was less than 5 mmHg and five developed a temporary choroidal detachment. At the last visit, IOP was regulated in 22 eyes (82.1%). There was no correlation between IOP regulation and the size of the filtering bleb or the increase in the latter by digital pressure. CONCLUSION: In the management of complicated glaucoma, if there is a high risk of failure due to conjunctival scarring, AGV implantation can be used as a save procedure with a success rate comparable to other glaucoma implants.

[Choroidal neovascularization followed in a patient with "Multiple Evanescent White Dot Syndrome" (MEWDS) -- a case report]. / Chorioidale Neovaskularisationsmembran bei einer Patientin mit "Multiple evanescent white dot Syndrome" -- Eine Kasuistik.

BACKGROUND: Since the description of the "multiple evanescent white dot syndrome" (MEWDS) by Jampol et al, choroiditis has been in the focus of interest. But the classical type of MEWDS was an exceptional case in clinical routine. CASE REPORT: A 48-year-old female presented to our hospital with a sudden unilateral visual acuity decrease and an extension of the blind spot. Ophthalmoscopy and fluorescein angiography revealed typical multiple grey-white chorioretinal patches of the same stage with lesion areas of about 100 - 200 microm compatible with the diagnose of MEWDS. Although visual acuity increased continuously the patient developed a classical choroidal neovascularization within 4 weeks. She was treated with PDT and visual acuity as well as the ophthalmoscopic diagnosis remained stable. CONCLUSION: In spite of visual improvement in MEWDS, regular control is recommended. In addition we propose to consider the diagnosis of MEWDS if an enlargement of the blind spot and CNV without lesions of the retinal pigment epithelium are diagnosed.

[Local anesthesia in ophthalmic surgery]. / Lokalanästhesie in der Ophthalmochirurgie.

In recent years anesthesia modalities have changed in ophthalmic surgery. A growing trend toward the use of topical anesthesia in cataract surgery is apparent. The present-day techniques used in ophthalmic surgery are retrobulbar anesthesia, peribulbar anesthesia, subtenon anesthesia, and subconjunctival anesthesia as injection techniques, topical anesthesia using drops, gel, or sponge, and intracameral anesthesia. Injectable anesthesia (RBA, PBA, STA) provides a higher level of analgesia and globe akinesia. With injection techniques the risks of vis a tergo and anesthetic complications increase; the level of analgesia after topical anesthesia could be improved by supplementation with i.v. narcotics.

[Manual endothelial cell enumeration for transplanted corneas in comparison to software controlled, automatic enumeration]. / Manuelle Endothelzellauszählung zu transplantierender Hornhäute im Vergleich zur softwaregesteuerten, automatisierten Auszählung.

BACKGROUND: The evaluation of the endothelial cells is the most important criterion for assessing human donor corneas. The number, morphology and the vitality of the endothelial cells are decisive for the transparency of a cornea. The study has the following aim: to verify whether there is any difference between the manual and the automatic count of the cells by means of the NAVIS(R) system. MATERIAL AND METHODS: Both methods were performed on 57 corneas of 35 patients. A photo was taken for the manual count by a microscope at 40-fold enlargement and was printed for further analysis. A grid was applied to this photo and the number of the endothelial cells was projected by a multiplicator to one square millimeter. For the automatic evaluation a picture was made with 20-fold microscopic enlargement; the examiner chose an area to be analysed. There the count of the cells was controlled by software and directly projected to one square millimetre. This was followed by a manual correction. The measurement data were statistically evaluated. RESULTS: No statistically significant difference was found between the manual and automatic counts. CONCLUSION: The manual count of the endothelial cells can be replaced by software-controlled automatic analysis and count.

Possibilities and limitations of current stereo-endoscopy.

BACKGROUND: Stereo-endoscopy has become a commonly used technology. In many comparative studies striking advantages of stereo-endoscopy over two-dimensional presentation could not be proven. To show the potential and fields for further improvement of this technology is the aim of this article. METHOD: The physiological basis of three-dimensional vision limitations of current stereo-endoscopes is discussed and fields for further research are indicated. New developments in spatial picture acquisition and spatial picture presentation are discussed. RESULTS: Current limitations of stereo-endoscopy that prevent a better ranking in comparative studies with two-dimensional presentation are mainly based on insufficient picture acquisition. CONCLUSION: Devices for three-dimensional picture presentation are at a more advanced developmental stage than devices for three-dimensional picture acquisition. Further research should emphasize the development of new devices for three-dimensional picture acquisition.

[Dry eye. An update on epidemiology, diagnosis, therapy and new concepts]. / Das trockene Auge. Ein Update über Epidemiologie, Diagnose, Therapie und neue Konzepte.

Recent epidemiologic studies quote a prevalence of 5,2% to 63% for dry eye depending on definition. Many risk factors have been identified, among other things the female gender. Dry eye interferes significantly with quality of live. Measurement of the change in temperature and humidity during blinking turned out to be a reliable diagnostic tool. Videokeratoscopy explains well-known visual impairments related to dry eye and, along with lipid film interferometry, provides insight into tear film dynamics. The importance of tear film proteins is underestimated. Among therapeutics for symptomatic relief hyaluronic acid proved to be particularly useful but also the sequence of lid hygiene, warm compresses and lid massage is fundamentally important. The effectiveness of punctum plugs is ascribed considerably to a more efficient impact of essential tear film components. Topical cyclosporine A, INS365, 15(S)-HETE as well as topical androgens represent a whole new class of drugs for causal therapy of dry eye.

Drainage devices in glaucoma surgery.

Glaucoma drainage devices, also termed aqueous shunts (AS), are widely used in the USA. Indications for AS include excessive conjunctival scarring diminishing the success of another filtration surgeries, abnormalities of the iridocorneal angle, neovascular glaucoma, presence of corneal grafts, and inflammatory glaucoma. Qualified success has been achieved for many years in 50 to 100 % of the treated eyes, depending on the patient selection. An AS consists of a silicone tube that is inserted into the anterior chamber and a plate (explant) made of silicone or polypropylene. The latter is positioned between the recti muscles. Within some weeks the surrounding tissue forms a fibrous bleb around the plate. This serves as a permanent filtration reservoir. The most serious complication is postoperative hypotonia, that can lead to serious choroidal detachment, suprachoroidal hemorrhage, anterior chamber flattening, and corneal decompensation. To avoid this complication some devices, e.g. the Ahmed Glaucoma valve and the Krupin valve, have integrated mechanisms to sustain a residual intraocular pressure. With other devices such as the Molteno and the Baerveldt devices the tube has to be temporarily ligated until a scar area forms around the explant. On the other hand, fibrous infiltration of the wall of the bleb often leads to a reversible rise in intraocular pressure about one to four months after surgery which can be treated by massaging the bulb, needling the bleb, or injection of antimetabolites. There are no obvious differences between the different AS regarding the success of pressure control. With appreciation of indications and therapy of complications, AS are an useful option in the management of complicated glaucoma, where conventional filtration surgery is considered to carry a high risk of failure.

[Comparison between optical and acoustical biometry]. / Comparaison entre biométrie optique et acoustique de l'oeil.

INTRODUCTION: Our current standard biometric measurement was compared to IOL-Master measurement. MATERIALS AND METHODS: One hundred sixty-two consecutive cataractous eyes were examined using the IOL-Master as well as the acoustic biometry combined with the Javal-Keratometer. In all eyes, the intraocular lens power to be implanted was chosen by means of the SRK/T formula, based on the measurements conducted with our standard method. The postoperative refraction achieved, obtained at least 6 weeks after surgery from the treating ophthalmologists, was communicated to us. The results were compared and analysed statistically. RESULTS: Comparison of the eye lengths, as well as of the keratometric measurements showed good correlation between the measurements obtained by both methods, the acoustic biometry yielding significantly (p < 0.001) shorter axial-lengths than the IOL-Master (r = 0.985) and the Javal yielding significantly (p < 0.001) higher mean corneal refraction power than the IOL-Master. The accuracy of the refraction obtained postoperatively compared to the preoperative aim was better with our standard method compared to the IOL-Master. CONCLUSIONS: The presumed systemic differences in measurement results could be verified. The IOL-Master currently has two advantages: it provides a substantial gain in time and the measurements can be delegated. Analysis of the subgroups showed that the "A" constant should be adapted with the IOL-Master to improve predictability of the postoperative refraction.

Melanoma-associated retinopathy: high frequency of subclinical findings in patients with melanoma.

BACKGROUND: Melanoma-associated retinopathy (MAR) is a paraneoplastic syndrome with symptoms of night blindness, light sensations, visual loss, defect in visual fields, and reduced b-waves in the electroretinogram. Patients with MAR often suffer from a sudden onset of ocular symptoms that are believed to result from antibody production against melanoma-associated antigens that cross-react with corresponding epitopes on retinal depolarizing bipolar cells. OBJECTIVES: To correlate the frequency of subclinical symptoms suggestive of MAR in melanoma patients to different stages of disease, patient age, type and thickness of the primary tumour, form of therapy, S-100 level and tumour burden. METHODS: We analysed 28 patients with melanoma in stages I-IV (according to the American Joint Committee on Cancer tumour classification) for the presence of subclinical MAR symptoms using scotopic electroretinography, static and kinetic perimetry and nyctometry. RESULTS: Seven patients had clinical signs and symptoms consistent with MAR, 18 had some indications, while the remaining three had none. We found no correlation between clinical symptoms and stage of disease, tumour burden or S-100 level, but findings suggestive of MAR were observed more frequently in advanced stages of disease. CONCLUSIONS: Subclinical retinal involvement characteristic of MAR appears to be more common than previously suspected in patients with cutaneous malignant melanoma. Our findings in this small cohort seem to indicate that the percentage of patients with symptoms suggestive of MAR is higher in advanced stages of disease. Further clinical studies are required to evaluate if the presence of subclinical symptoms suggestive of MAR is correlated with a worse prognosis and a shortened progression-free and overall survival.

Oral premedication with low dose midazolam modifies the immunological stress reaction after the setting of retrobulbar anaesthesia.

BACKGROUND/AIMS: An acute immunological stress reaction was previously reported to occur after the painful setting of retrobulbar anaesthesia before intraocular surgery. This study was conducted to find out whether an oral low dose premedication with midazolam would modify the immunological stress reaction. METHODS: 32 patients undergoing intraocular surgery using retrobulbar anaesthesia were included in a randomised, double blind trial. They received premedication with either 3.75 mg midazolam or placebo 30 minutes before the retrobulbar injection. Counts of leucocyte subpopulations, cardiovascular, and psychometric parameters were measured repetitively before and after the retrobulbar injection. RESULTS: The numbers of leucocytes increased significantly in the placebo group after the setting of retrobulbar anaesthesia (before retrobulbar injection: 6687 (SD 1025) cells x10(6)/l; after injection: 7067 (1022) cells x10(6)/l, p=0.0009) caused by rising numbers of neutrophils (before injection: 4111 (1063) cells x10(6)/l; after injection: 4352 (1147) cells x10(6)/l, p=0.0007) and natural killer cells (before injection: 290 (84) cell x10(6)/l; after injection 354 (133) cells x10(6)/l, p=0.003). There was no significant increase in total leucocytes (before injection: 5997 (1288) cells x10(6)/l; after injection: 6189 (1215) cells x10(6)/l) or in any leucocyte subpopulation in the midazolam group. A significant rise in systolic blood pressure occurred in the placebo group, but not in the midazolam group. CONCLUSION: A low dose premedication with midazolam attenuates the immunological and cardiovascular stress reactions occurring with retrobulbar anaesthesia.