[Long-term outcome of keratoprosthesis with biological support]. / Langzeitverlauf nach Keratoprothesen mit biologischer Haptik.

BACKGROUND: In severe Sicca syndrome and limbal stem cell deficiency, vision can be restored by an artificial optical implant into the cornea (keratoprosthesis, KPro). After multiple efforts to achieve long-lasting corneal fixation of such an optical implant, two methods have become established: KPro with biological support, such as osteo-odonto-keratoprosthesis (OOKP) made from the root of patient's own tooth or osteo-keratoprosthesis (OKP), made from cortical bone of the patient's tibia; and the Boston KPro. MATERIALS AND METHODS: We examined the long-term outcome of a total of 93 patients with biological support, 59 with OOKP and 34 with OKP, and compared the results with the latest literature on Boston KPro. RESULTS: Medium follow-up was 7.5 years (max. 20.6 years) in OOKP and 4.5 years (max. 13.2 years) in OKP. The percentage of anatomic survival in Kaplan-Meier analysis was 95 and 89% after 2 years, 92 and 81% after 5 years, and 89 and 81% after 10 years, for OOKP and OKP, respectively; and 84% after 15 years and 56% after 20 years for OOKP. In the case of an autoimmunologic process underlying the corneal disease, long-term results are slightly worse than for non-autoimmunologic cases, but a literature comparison revealed that they are still better than with the Boston KPro. CONCLUSION: OOKP has a slightly better anatomic survival rate than OKP. Comparison with the literature reveals the medium anatomic survival rate to be better for KPro with biological support than for Boston KPro. The OOKP is still the gold standard in KPro.

[Health-related quality of life after implantation of a keratoprosthesis with biological haptic]. / Gesundheitsbezogene Lebensqualität nach Implantation einer Keratoprothese mit biologischer Haptik.

BACKGROUND: Many studies report comparatively good long-term results among patients with keratoprostheses with biological haptic. However, overall costs are correspondingly high. A clear cost-benefit relationship is therefore desirable. OBJECTIVE: This study investigates health-related quality of life after implantation of a keratoprosthesis with biological haptic. MATERIALS AND METHODS: We present a retrospective analysis of medical data of 25 patients treated between 1996 and 2006 at the Department of Ophthalmology, University Hospital Homburg/Saar and the Klinikum Offenburg. Health-related quality of life was assessed by means of a questionnaire based on validated instruments, with particular emphasis on physical symptoms, mental health, functional limitations, and social interactions. RESULTS: At a patient age of 49.8 ± 15.7 years (minimum-maximum: 19-78 years; 6 female, 19 male), the mean duration of corneal blindness was 13.8 ± 13.1 years (minimum-maximum: 1-47 years). Changes in visual acuity and subjective satisfaction were statistically significant (p <0.001). Quality of life (on a scale of 1 to 6: median 2) at the time "before the onset of eye disease" and ≥15 months after surgery were identical. Patients with a postoperative visual acuity ≤0.1 (n =11) also showed a statistically significant (p =0.016) benefit in this context. CONCLUSION: The expenditures and costs of keratoprosthetics can be justified by an improvement in the health-related quality of life of the persons concerned. Even a postoperative visual acuity of ≤0.1 correlates with a statistically significant improvement in the subjective quality of life of these patients.

Low-level antimicrobial resistance of Enterobacteriaceae isolated from the nares of pig-exposed persons.

Extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) have recently emerged in livestock and humans. Therefore, this study assessed the carriage of Enterobacteriaceae in the anterior nares and associated antimicrobial resistance in pig-exposed persons. Nasal swabs were enriched in non-selective broth and then plated on MacConkey and ESBL-selective agars. Species was confirmed by matrix-assisted laser-desorption ionization-time-of-flight mass spectrometry (MALDI-ToF MS). Antimicrobial susceptibility testing was performed according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Of 114 pig-exposed persons tested, Enterobacteriaceae were detected in the nares of 76 (66·7%) participants. The predominant species were Proteus mirabilis (n = 17, 14·9%), Pantoea agglomerans (n = 13, 11·4%), Morganella morganii (n = 9, 7·9%), Citrobacter koseri (n = 9, 7·9%), Klebsiella pneumoniae, Escherichia coli and Proteus vulgaris (each n = 8, 7·0%). ESBL-E were not detected. Of all isolates tested, 3·4% were resistant against ciprofloxacin, 2·3% against gentamicin, 23·9% against trimethoprim-sulfamethoxazole and 44·3% against tigecycline. Despite the high prevalence of ESBL-E in livestock, pig-exposed persons did not carry ESBL-E in their nares. This finding is important, because colonization of the nasal reservoir might cause endogenous infections or facilitate transmission of ESBL-E in the general population.

[Current treatment options with artificial corneas: Boston Kpro, Osteo-odontokeratoprosthesis, Miro Cornea® and KeraKlear®]. / Aktuelle Versorgungsmöglichkeiten mit Keratoprothesen : Boston-Keratoprothese, Osteoodontokeratoprothese, Miro Cornea® und KeraKlear®

BACKGROUND: Although corneal transplant surgery in avascular normal risk eyes is becoming even more minimally invasive and successful, treatment options for difficult to treat patients with high risk eyes are still limited. In these cases HLA typed allogeneic transplants and artificial corneas (keratoprostheses) can be used. METHODS: This article combines a review of the literature in PubMed and own clinical experiences on the use of artificial corneas in high risk eyes. Osteo-odontokeratoprosthesis (OOKP), Boston Kpro, Miro Cornea® and KeraKlear® corneas were used as clinical keratoprostheses. RESULTS: Worldwide, the most experience exists for the use of Boston Kpro and OOKP in high risk eyes. Miro Cornea® and KeraKlear® are new procedures where only preliminary results are available and further evaluation is necessary. The longest experience and best anatomical long-term results have been achieved with OOKPs. Comparable cohorts are available for the Boston Kpro. The function of all keratoprostheses is threatened by secondary glaucoma. Implantation of the KeraKlear® prosthesis remains difficult. The Miro Cornea® shows an initially stable integration behavior. CONCLUSION: Keratoprostheses, such as the Boston Kpro and OOKP are valid treatment options for eyes which are not open to therapy with allogeneic corneal transplantation. Modern implants such as KeraKlear® prosthesis and Miro Cornea® need further prospective clinical evaluation.

Osteo-odonto-keratoprosthesis (OOKP) and the testing of three different adhesives for bonding bovine teeth with optical poly-(methyl methacrylate) (PMMA) cylinder.

AIM: Preparation of the lamina during osteo-odonto-keratoprosthesis (OOKP) design is complex, and its longevity and watertightness important. To date, only acrylic bone cements have been used for bonding the optical cylinder to the tooth dentine. Our aim was to evaluate different dental adhesives for OOKP preparation. METHODS: Specimens of bovine teeth were produced by preparing 1.5-mm thick dentine slices with holes having a diameter of 3.5 mm. Each group (n=10 per group) was luted with either classic poly-(methyl methacrylate) (PMMA) bone cement, universal resin cement or glass ionomer cement. All specimens underwent force measurement using a uniaxial traction machine. RESULTS: The highest mean force required to break the bond was measured for PMMA bone cement (128.2 N) followed by universal resin cement (127.9 N), with no statistically significant difference. Glass ionomer cement showed significantly lower force resistance (78.1 N). CONCLUSIONS: Excellent bonding strength combined with easy application was found for universal resin cement, and thus, it is a potential alternative to acrylic bone cement in OOKP preparation.

[Visual acuity and astigmatism after keratoplasty. Differences between the guided trephine system and motor trephine]. / Visus und Astigmatismus nach Keratoplastik. Unterschiede zwischen geführtem Trepansystem und Motortrepan.

BACKGROUND: The purpose of this study was to assess the differences in postoperative visual acuity, astigmatism, and selected postoperative complications between a guided trephine system (GTS) and motor trephine after penetrating keratoplasty. PATIENTS AND METHODS: In this retrospective analysis 74 patients who had undergone penetrating keratoplasty either by GTS (n = 53) or by motor trephine (Motortrepan) (n = 21) were included. Both patient groups included in this analysis were selected to ensure a homogeneous distribution of preoperative parameters to the greatest possible extent. However, some significant differences in patient selection between the two groups could not be avoided. Patients in the motor trephine group were older (mean age 68.4 years vs 56.4 years; p < 0.01) and had Fuchs' endothelial dystrophy more often (47.6 % vs 26.4 %) and significantly less keratoconus (14.3 % vs 32.1 %). RESULTS: No significant differences regarding visual acuity outcomes could be found between GTS and Motortrepan. In both patient groups there were no differences in the amount of preoperative astigmatism (1.36 vs. 2.0 dpt., p = 0.39). However, at the time of final corneal suture removal (2.23 vs. 3.5 dpt., p = 0.03) and at a postoperative control 1 year after final suture removal (2.29 vs. 3.85 dpt., p = 0.005) the amount of astigmatism in the motor trephine group was found to be significantly higher. CONCLUSION: In summary penetrating kerastoplasty using the motor trephine was found to result in significantly higher postoperative astigmatism than those performed with the GTS.

Owner-collected swabs of pets: a method fit for the purpose of zoonoses research.

As part of the preparation of a large cohort study in the entire German population, this study examined the feasibility of cat and dog owners collecting nasal and oral swabs of their animals at home as a method of assessing exposure to zoonoses. In veterinary clinics in Hannover, Germany, 100 pet owners were recruited. Nasal and oral swabs of pets were taken by a veterinarian at the clinic and owners took swabs at home. Swabs were analysed regarding bacterial growth and compared (owner vs. vet) using Cohen's kappa and McNemar's test. The return rate of kits was 92%, and 77% of owners thought it unnecessary to have veterinarian assistance to swab the mouth. McNemar's test results: oral swabs 78% agreement with Gram-positive bacterial growth, 87% agreement with Gram-negative bacterial growth; with similar results for nasal swabs. Although sample quality differed, this method allowed the receipt of swabs from pets in order to obtain information about colonization with zoonotic pathogens.

Years of potential life lost for six major enteric pathogens, Germany, 2004-2008.

In industrialized countries, acute infectious enteric diseases are usually mild, but they can also cause death. They do so, however, at different ages. Using 2004-2008 German notification data, we computed and compared crude and premature mortality [three different measures of years of potential life lost (YPLL)] of illnesses caused by Campylobacter spp., Listeria monocytogenes, norovirus, rotavirus, non-typhoidal Salmonella spp., and Shiga toxin-producing E. coli (STEC). Among ~1.5 million notified illnesses, those caused by norovirus were the most frequent. The highest annual mortality was registered for salmonellosis (0.55/1 000 000 population), but listeriosis accounted for the highest number of YPLL (n=4245). Disregarding death at advanced age (i.e. >70 years), STEC illness (n=757) and rotavirus gastroenteritis (n=648) ranked second and third, following listeriosis (n=2306). Routine surveillance captures only a fraction of all incident cases and deaths, under-ascertaining the true burden of disease. Weighting death by age permits a different view on the disease burden individual enteric pathogens cause and particularly underscores the public health importance of listeriosis prevention.

[Comparison of pars plana vitrectomy with ILM peeling and intravitreal triamcinolone in diffuse diabetic macular oedema]. / Pars-plana-Vitrektomie mit ILM-Peeling versus intravitreale Triamcinolon-Injektion bei diffusem diabetischem Makulaödem.

BACKGROUND: Visual outcome and anatomic results in patients with diffuse diabetic macular oedema (DDME) were evaluated after vitrectomy with internal limiting membrane (ILM) peeling versus intravitreal triamcinolone acetonide (TA). MATERIALS AND METHODS: A prospective, non-randomised pilot study included 41 eyes (35 patients) with clinically significant DDME. In 24 eyes (group A) we performed pars plana vitrectomy with ILM peeling. Seventeen eyes (group B) received an injection of 10 mg TA. Best corrected visual acuity and central macular thickness (measured with OCT) were determined preoperatively as well as 1 and 4 months postoperatively. RESULTS: In group A, OCT showed a macular thickness of 403 +/- 142 microm preoperatively. Best corrected visual acuity was 0.24 +/- 0.18. One month after surgery, macular thickness decreased to 311 +/- 62 microm (p = 0.06 ns) and visual acuity was 0.17 +/- 0.14 (ns). Four months after surgery, macular thickness remained significantly lower compared with preoperative values, at 307 +/- 161 microm (p = 0.012). There was a tendency towards a higher visual acuity of 0.30 +/- 0.26 (p = 0.32 ns). Before TA injection, macular thickness in group B was 551 +/- 180 microm and visual acuity was 0.19 +/- 0.14. One month after TA, macular thickness decreased to 242 +/- 82 (p = 0.001) microm while visual acuity increased to 0.31 +/- 0.21 (p = 0.005). At 4 months follow-up, group B showed recurrence of macular oedema. Compared with the preoperative findings macular thickness was significantly lower (368 +/- 159 microm; p = 0,001). Best corrected visual acuity after 4 months was 0.27 +/- 0.17 and did not differ significantly from the preoperative visual acuity (p = 0.033 ns). CONCLUSIONS: Intravitreal TA as a single treatment reduces the extent of DDME within a short time after surgery. These promising results may not be stable during long-term follow-up, necessitating in many cases a re-injection of TA. Macular oedema reduction after vitrectomy with ILM peeling, however, remains stable for more than 4 months and, therefore, offers more permanent results. However, none of these treatments facilitated a significant visual acuity restoration 4 months postoperatively.

[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.

[On the effectiveness of the postsurgical mono- or combination therapy after cataract operations]. / Zur Wirksamkeit der postoperativen Mono- bzw. Kombinationstherapie nach Kataraktoperation.

BACKGROUND: In postoperative inflammatory diseases of the anterior segment of the eye the cause of the inflammation on the one hand and symptoms on the other hand have to be treated. Exactly this target can be reached by a combination of the active ingredients dexamethasone and gentamicin. In the present study we compared a fixed combination therapy with the consecutive application of the same substances. PATIENTS AND METHODS: We examined the effectiveness and handling of a fixed combination in a prospective, single-masked, randomised, comparing, controlled parallel group design study in comparison with a separate application of dexamethason and gentamicin sulfate in cataract patients. The main target criteria was the postoperative inflammation measured by of the laser-flare meter and clinical parameters. In addition different investigations were accomplished for the estimation of the compliance and the subjective tolerability. RESULTS: There was a significantly lower inflammation rate measured by the Tyndall value and the clinical examination on days 7 and 14 after cataract surgery on applying the combined medicinal product in comparison to applying the same active ingredients but in separate eye drops. CONCLUSIONS: Patients receiving the fixed combination will have advantages compared to those patients receiving the active ingredients as single agent therapy. A major advantage of a combined medicinal product is the lack of a wash-out effect with the combination therapy. Therefore, such a therapeutic possibility should chosen for ophthalmological patients.

[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.

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.

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.

[Drainage systems in glaucoma surgery]. / Drainagesysteme in der Glaukomchirurgie.

Glaucoma drainage devices, also known as aqueous shunts (AS) are widely used in the USA. They consist of a silicone tube that is inserted into the anterior chamber and connected to a plate made of silicone or polypropylene, the explant. The latter is positioned between the recti muscles and over several weeks the surrounding tissue forms a fibrous bleb around the plate. This serves as a permanent filtration reservoir.Recurrent failure of filtrating surgery is the main indication for the use of AS. Other indications include situations in which the formation of a filtering bleb seems to be unpromising because of extensive conjunctival scarring. Qualified success has been achieved for many years in 50-100% of the eyes treated depending on patient selection. The most serious complication is postoperative hypotonia that can lead to serious chorioidal detachment, suprachorioidal hemorrhage, flat anterior chamber and corneal decompensation. To avoid this complication some devices, i.e.the Ahmed Glaucoma and the Krupin valve have integrated mechanisms to sustain a residual intraocular pressure. With other devices i.e. the Molteno and the Baerveldt devices, the tube has to be temporarily ligated until bleb formation has started. On the other hand fibrous infiltration of the bleb 1-4 months after the surgery often leads to a reversible rise in introcular pressure, which can be treated by massaging the bulbus, needling the bleb or injection of antimetabolites. There are no obvious differences between the various forms of AS with regard to the success of pressure regulation. In summary,by close scrutiny of indications and management of complications,drainage systems are a useful option in the management of complicated glaucoma that carry a high risk of failure from conventional filtering surgery.

Risk factors for anatomical success and visual outcome in patients undergoing silicone oil removal.

PURPOSE: To define risk factors for anatomical success and visual outcome in patients undergoing removal of silicone oil. METHODS: This retrospective study included patients who had silicone oil removed at this hospital between 1996 and 2000. All were followed for at least six months. Patients with recurrent retinal detachment after silicone oil removal were compared with patients without this complication. We also compared patients whose vision improved or stabilized with patients whose vision deteriorated. Risk factors for anatomical success and visual outcome were identified. RESULTS: We analysed 94 eyes of 92 patients with silicone oil removal. Nineteen eyes (20%) had recurrent retinal detachment, and in 30 eyes (32%), the vision deteriorated after removal of the oil. Initial vision less than ambulatory vision, initial pathology of giant retinal tears and recurrent retinal detachment, postoperative hypotony and postoperative epiretinal membrane occurred more frequently in eyes with than without recurrent retinal detachment. Pre- and postoperative hypotony, postoperative epiretinal membranes and postoperative recurrent retinal detachment were also more frequent in eyes with deteriorated vision. CONCLUSIONS: When treating giant retinal tears or recurrent retinal detachments with silicone oil tamponade, surgeons and their patients need to be aware of the higher possibility of unfavorable results, particularly when the initial vision is less than ambulatory vision. The presence of risk factors before and after silicone oil removal should remind surgeons of the higher risk profile of this particular surgery.

[Keratoprostheses. Historical overview, materials and status of current research]. / Keratoprothesen. Historischer Uberblick, Materialien und Stand der gegenwärtigen Forschung.

The idea to substitute optically clear material in an opaque cornea is two centuries old and in that time experiments have been carried out in animals and patients without much success. The historical development of and the clinical experiences with keratoprostheses are described. Especially in the last 40 years there have been great efforts concerning design, fixation, material and surgical technique to create a device with long-term success. The best long-term survival rates are achieved with the osteo-odontokeratoprosthesis, as it is the only model with a biological haptic. Due to some disadvantages of this procedure the present research is looking for new, soft materials and surface modifications to create a biointegrable artificial cornea.

[Keratoprostheses. Clinical aspects]. / Keratoprothesen. Klinische Aspekte.

In patients with dry eye, like pemphigoid, Fuchs-Stevens-Johnson syndrome and xerophthalmia, in eyes with severe vascularisation of the cornea due to severe burns, in a leucoma adherens or following recurrent transplant rejections as well as in cloudy corneas of silicone-filled eyes, restoration of visual acuity can often only be achieved by a keratoprosthesis. In the case of an intact posterior segment and retinal function a normal visual acuity can be anticipated but mostly with a restricted visual field. Complications vary from glaucoma, retroprosthetic membranes, necrosis of the recipient tissue at the rim of the prosthesis, endophthalmitis, loosening and loss of the prosthesis even to the loss of visual acuity. With some types of prostheses the visual acuity will be reduced again within a short time, but in osteo-odonto-keratoprostheses, using the root of a patients tooth as haptic material for the optical cylinder, good long-term results even for several decades are possible. In patients without suitable teeth, prostheses with biointegrable materials such as Pintucci keratoprostheses can be used. A basic rule is that a secondary glaucoma, which in this patient group frequently develops even preoperatively, must be treated adequately.