[Complications of Descemet Stripping Automated Endothelial Keratoplasty (DSAEK)]. / Komplikationen der Descemet Stripping Automatisierten Endothelkeratoplastik (DSAEK).

BACKGROUND: Lamellar keratoplasties, e.g. Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) are considered the procedures of choice for corneal endothelial diseases. In comparison to penetrating keratoplasty (PK) they are associated with faster visual rehabilitation, a lower risk of complications and a decreased necessity for follow-up visits, which reduces the burden on quality of life in elderly patients. In order to advise patients regarding the indications for surgery and to facilitate the follow-up management, it is important to know the most important complications associated with these keratoplasty techniques. RESULTS AND DISCUSSION: The most important preoperative complication is a delayed indication for the operation. In contrast to PK, DSAEK and DMEK surgery should be provided at an earlier stage of disease as chronic edema alters the stroma and reduces the speed of visual recovery. The most important complications during or early after surgery are detached lamellae, pupillary blocks with increased pressure or air bubbles in the vitreous cavity in patients with previous vitrectomy. The main long-term complications include chronic increased intraocular pressure and immune-mediated graft rejections in DSAEK patients after reducing or stopping topical corticosteroid therapy. This article describes the potential complications of endothelial keratoplasty and provides a detailed explanation of strategies to avoid these complications.

Intraoperative testing of opening and closing pressure predicts risk of low intraocular pressure after Ahmed glaucoma valve implantation.

PURPOSE: The aim of this study was to assess whether intraoperative testing of silicone Ahmed glaucoma valves (AGVs) would identify valves with an increased risk of low postoperative intraocular pressure (IOP). METHODS: In 30 consecutive cases of glaucoma surgery with AGV implantation, after priming the AGV, we intraoperatively measured the opening pressure A, closing pressure B, and re-opening pressure C using the active infusion pump of a phako-machine. IOP was checked postoperatively on the same day. Low IOP was defined as <5 mm Hg. Intraoperatively measured pressure characteristics of the valve function were analysed for their ability to predict postoperative IOP outcomes. RESULTS: Opening A, closing B, and re-opening C pressures (mean, (SD)) were 18.4 (5.1), 8.3 (4.7), and 11.7 (4.8)mm Hg, respectively. Ten patients (33.3%) had low IOP. An opening pressure of ≤18 mm Hg predicted low postoperative IOP with a sensitivity (10/10) of 100% (95% CI, 69.2-100) and a specificity (13/20) of 65.0% (95% CI, 40.8-84.6). CONCLUSIONS: AGVs have a high variability of opening, closing, and re-opening pressures. An opening pressure of ≤18 mm Hg, a closing pressure of ≤10 mm Hg, or a re-opening pressure of ≤11 mm Hg identified all patients with low postoperative IOP.

Central corneal regularization--optimization of uncorrected visual acuity in keratoconus patients.

BACKGROUND: Combined excimer laser correction and corneal cross-linking is a promising concept in treating keratoconus patients. Central corneal regularization represents advanced topography-guided custom ablation for ectatic corneas, aiming at correcting irregular astigmatism and at increasing the optical regularity of the corneal surface. PATIENTS AND METHODS: In a prospective single centre study, 10 keratoconus patients underwent combined treatment with corneal cross-linking and central corneal regularization by an iRES-Laser. Uncorrected visual acuity at 1 and 3 months postoperatively represented the primary endpoint. RESULTS: Mean preoperative uncorrected decimal visual acuity was 0.15 (± 0.28 standard deviation). Mean postoperative visual acuity was 0.28 (± 0.47) at one month and 0.24 (± 0.25) at three months, respectively. CONCLUSIONS: Combined corneal cross-linking and central corneal regularization treatment has the potential to achieve a clinically significant improvement of uncorrected visual acuity.

The impact of infectious ocular emergencies on hospital resources.

BACKGROUND: Infectious ocular emergencies cannot be pre-planned, need a more labour-intensive treatment and are often associated with prolonged hospitalisation. The aim of this study is to assess the impact of infectious ocular emergencies on hospital resources and identify changing trends over the last 10 years. PATIENTS AND METHODS: In a retrospective chart review 13,587 inpatient records from 1998 to 2007 were analyzed for the reason for emergency hospitalization, treatment data, length of hospitalizations and economical impact. RESULTS: 341 cases of severe infectious ocular emergencies with the need for emergency hospitalization were identified. The annual incidence of such emergencies increased continuously and has more than doubled during the last 10 years (51 vs. 24 annual cases). Within the same period the average hospitalization time of all non-infectious patients decreased from 5.41 to 4.95 days while inpatient stay due to infectious ocular emergencies decreased from 10.13 to 8.18 days. The average nursing effort was 4.26 hours per day in the infectious group, while electively admitted patients had an average requirement for nursing time of only 2.92 hours per day. CONCLUSION: The increase in infectious-related hospitalizations, their unpredictability and the need for a more intensive treatment regime have an increasing impact on hospital resources.

Predictability of microkeratome-dependent flap thickness for DSAEK.

BACKGROUND: The recommended thickness of the graft lamella in Descemet's stripping automated endothelial keratoplasty (DSAEK) is 120 - 180 microm. To adjust for the large variation in central corneal thickness (CCT) of eye bank donor corneas, microkeratome plates of different heights are available. The aim of this study was to evaluate the lamella thickness predictability of different keratome plates in a clinical routine setting. METHODS: In a prospective study of 60 consecutive DSAEK procedures, CCT was measured with a 50 MHz ultrasound pachymeter after meticulous epithelium removal immediately before and after lamella creation. Selected plate thickness was 300, 350, or 400 micro, respectively. Cutting depth was calculated by subtracting the remaining CCT of the deep lamella after the cut from the initial CCT before the cut. RESULTS: The mean (+/- SD) cutting depth was 320 +/- 45 microm with the Amadeus 350 keratome, 317 +/- 48 microm with the Moria 300 keratome, 388 +/- 58 microm with the Moria 350 keratome and 467 +/- 94 microm with the Moria 400 keratome. Neither the duration nor the type of donor preservation had an effect on the accuracy of the cutting depth. CONCLUSION: The mean cutting depth for the DSAEK keratomes is more accurate than the cutting depth of the same keratome heads designed for LASIK. This might be due to the fact that DSAEK lamellas were cut after complete epithelial removal. Despite the accurate mean cutting accuracy, there is a substantial variation between individual cuts which have to be taken into consideration.

Comparison of dynamic contour tonometry with Goldmann applanation tonometry following Descemet's stripping automated endothelial keratoplasty (DSAEK).

BACKGROUND: Intraocular pressure (IOP) measurements using Goldmann applanation tonometry (GAT) are influenced by central corneal thickness (CCT) whereas dynamic contour tonometry (DCT) allows for IOP measurements independent of CCT. After Descemet's stripping automated endothelial keratoplasty (DSAEK) the CCT is, compared to healthy eyes, increased. The objective of this prospective study was to compare IOP measurements obtained by DCT and GAT in patients after a DSAEK procedure. PATIENTS AND METHODS: DCT and GAT were performed 3 and/or 6 months after DSAEK. Comparison of means was performed using the Wilcoxon signed-ranks test. RESULTS: In total, 50 IOP measurements on 33 eyes were obtained. Mean CCT was 621 (+/- 60) microm. Overall correlation between GAT and DCT was good, however, in some patients a remarkable difference between pressure readings of up to 10.8 mmHg was observed. Mean IOP readings obtained by DCT were significantly higher (20.9 +/- 5.9 mmHg) than those obtained by GAT (19.1 +/- 6.5 mmHg; p = 0.0002). However, the difference between GAT and DCT readings was not influenced by the thickness of the transplanted lamella. DISCUSSION: The well-known difference in mean pressure readings between DCT and GAT was not affected by the increase in CCT following DSAEK. IOP readings with the GAT seem not to be influenced by the increase in CCT. Because of the remarkable differences in individual pairs of IOP measurements, both GAT and DCT should be used after DSAEK.

The disc damage likelihood scale (DDLS): interobserver agreement of a new grading system to assess glaucomatous optic disc damage.

BACKGROUND: The disc damage likelihood scale (DDLS) is a new grading system to estimate the amount of optic disc damage in glaucoma patients. The objective of this study was to assess the interobserver agreement of the DDLS and the cup/disc ratio. PATIENTS AND METHODS: The reproducibility of the DDLS and the cup/disc ratio was measured by two masked observers (one glaucoma specialist and one of two resident physicians in their first 6 months of training) staging 42 eyes of 25 patients with glaucoma or ocular hypertension. Disc size, cup/disc ratio and DDLS were documented and the Cohen's kappa was calculated as a measure for interobserver agreement. RESULTS: The interobserver agreement for the cup/disc ratio was good (Cohen's kappa 0.803). For the DDLS, the interobserver agreement was even better (Cohen's kappa 0.902). DISCUSSION: Unlike the cup/disc ratio, which focuses on the excavation, the DDLS is based directly on the thickness of the neuroretinal rim and takes into account the optic disc size. Therefore, the DDLS estimates the glaucomatous damage of the optic disc more precisely than the currently used method. Although this new grading system is more complicated to use in clinical practice, the interobserver agreement for the DDLS in our study setting was very good.

Increasing the size of a small peripheral iridotomy widens the anterior chamber angle: an ultrasound biomicroscopy study.

PURPOSE: A peripheral iridotomy (PI) is the treatment of choice for pupillary block. In this study we investigated the effect of enlarging the size of a small PI on the anterior chamber angle in patients with angle closure using ultrasound biomicroscopy (UBM). PATIENTS AND METHODS: Patients who had been treated with laser peripheral iridotomy for angle closure and were identified to have a small patent PI (< 100 microm) with still appositionally closed anterior chamber angle were selected prospectively. The anterior chamber angle was assessed using UBM. The angle opening distance 500 microm from the scleral spur (AOD500) as well as the anterior and posterior chamber depth (ACD and PCD) 1000 microm from the scleral spur was measured. In addition, the ACD/PCD ratio was calculated. Afterwards, the PI was enlarged using an Nd: YAG laser and the UBM measurements were repeated as described above. RESULTS: Six eyes of six patients were examined. After the enlargement of the PI the average AOD500 increased from 109 microm (+/- 36) to 147 microm (+/- 40) (p < 0.05). The ACD/PCD ratio increased from 0.36 (+/- 0.065) to 0.67 (+/- 0.185) (p < 0.05). CONCLUSION: Patients with a small PI and appositionally closed anterior chamber angle should have a repeated laser treatment. The ACD/PCD ratio, measured 1000 microm from the sclerl spur, is a new method to describe the features and changes of the anterior chamber angle taking into account the configuration of the iris and the posterior chamber depth.

[Psychiatric and clinico-psychologic epidemiology: critique of methods and systematization approach]. / Psychiatrische und klinisch-psychologische Epidemiologie: Methodenkritik und Systematisierungsansätze.

The development of typical epidemiological questions is discussed. Possible definitions und fields of applications for simple status-diagnostics as well as for epidemiological longitudinal research are presented. Examples for the application of complex mathematical models like LOGIT- or LISREL-analysis are presented. Insufficient methodological systematisation and problems in comparing studies of different origin (i.e. for metaanalysis) are identified as problems for the future development of epidemiology. A classification system of epidemiological methods is presented that includes content aspects as well as methodological aspects on four levels. These are: the demand of the study (descriptive vs. inferential), the time dimension (status diagnostics vs. longitudinal research), the content level of operationalisation (micro- vs. macrolevel) and the level of explanation (correlative vs. causal). Examples show that this system can be used for classification of existing studies as well as for the conceptualisation and optimization of planned studies.

[Bronchial asthma in childhood and adolescence. Burden of illness and coping with the disease]. / Asthma bronchiale im Kindes- und Jugendalter. Krankheitsbelastung und Krankheitsbewältigung.

We report an empirical study in which the subjective complaints and stress experiences of children with bronchial asthma (outpatient, short- and long-term rehabilitation) are analyzed. The data were taken from a specifically developed questionnaire. The results should contribute to the conceptualization of programs for patient education and asthma training in order to meet the exact requirements and needs of the children to be instructed. The role of emotional asthma triggers is specified. Hierarchical cluster analysis is applied in order to analyze, first, the perception patterns of attack precursors and, second, the array of stressors that a child has to face as a consequence of suffering chronic asthma. Based on the social learning theory approach, the child's various expectations about the controllability of an asthma attack are differentiated. A factor analysis reveals that the coping process can be described by two basic coping dimensions.

[Compliance in forms of drug therapy with special reference to aspects of trust]. / Compliance bei medikamentösen Therapieformen unter besonderer Berücksichtigung von Vertrauensaspekten.

This study investigates the compliance in respect to medication. Because of the so far wide ranging and often methodologically differing ways of documentation and description of compliance, we first had to start by determining the term in accordance with the current scientific discussion. The following step was to demonstrate similarities and differences of the compliance in relation to trust by empirical data. Empirical methods: A sample of ten persons was interviewed by a semi-standardized questionnaire, in order to find the constructs of compliance and trust in reference to the medication. These interviews were based on a theoretical analysis. The evaluation of the interview showed 21 constructs for compliance and 14 constructs for the description of trust in the therapeutic situation. These constructs were combined with control questions in a likert-rated questionnaire, which was answered by 160 representative test persons. From the thus required data 6 factors of compliance and 5 factors of the trust were isolated in a factor analysis. A comparison of compliance and trust by a regression-analysis showed that it is not possible to exchange both constructs completely. The limit of the exchangeability is given by medical factors such as side-effects or the knowledge about a given medication. Thus it was demonstrated that it is possible to increase compliance by trust. However, compliance is made up by different factors which are hardly modified by trust.