[Differentiation of ocular hypertension]. / Abgrenzung der okulären Hypertension.

The term ocular hypertension has been used for more than 30 years. It is defined as an elevated intraocular pressure above the statistical norm without detectable optic nerve head or visual field damage. The number of patients with ocular hypertension in Germany is estimated to be approximately 3-5 million. Increased intraocular pressure is a risk factor for conversion to primary open-angle glaucoma. Most patients with ocular hypertension (and no risk factors) can be followed on a regular basis without any treatment. Each visit should include measurement of intraocular pressure, optic nerve head examination with a slit lamp, imaging and perimetric examinations. Currently known risk factors are high intraocular pressure, higher age, myopia, a thin cornea and darkly pigmented skin. If risk factors are present, antiglaucomatous therapy is indicated.

Peripapillary Choroidal Thickness and Choroidal Area in Glaucoma, Ocular Hypertension and Healthy Subjects by SD-OCT.

BACKGROUND: The exact pathogenesis of open angle glaucoma and ocular hypertension remains unclear. Hemodynamic influences are discussed as potential risk factors and the choroid may play an important role in the pathogenesis of open angle glaucoma or ocular hypertension. The current study investigates peripapillary choroidal thickness and choroidal area in patients with open angle glaucoma, subjects with ocular hypertension and healthy subjects using spectral-domain OCT. It furthermore assesses the association between peripapillary choroidal thickness and age, central corneal thickness, refractive error and intraocular pressure. PATIENTS AND METHODS: Prospectively recorded data of 213 eyes of 177 open angle glaucoma patients, 73 eyes of 50 subjects with ocular hypertension and 152 eyes of 116 healthy control subjects were analyzed by fitting a linear mixed model including age and disease. RESULTS: Peripapillary choroidal thickness was thinnest in glaucoma patients (125 µm), followed by healthy subjects (127 µm) and ocular hypertensive subjects (135 µm). A marginally significant difference was present between ocular hypertension and glaucoma (p=0.059). Thickest choroids were found superiorly and thinnest choroids inferiorly. Choroidal area was highest in the supero-nasal and lowest in the infero-temporal sectors. Choroidal thickness decreased with age, no significant correlation was evident between peripapillary choroidal thickness and refractive error or intraocular pressure. Peripapillary choroidal thickness and central corneal thickness are significantly negative correlated in healthy subjects. CONCLUSIONS: There is a trend towards thicker choroids in ocular hypertensive subjects compared to healthy subjects or glaucoma patients. Thickest choroids are found superiorly, thinnest inferiorly. Interestingly, choroidal area is thinnest in the temporal-inferior sector, one of the regions where glaucomatous damage tends to start.

[Morbus Morbihan : A rare cause of edematous swelling of the eyelids]. / Morbus Morbihan : Seltene Ursache ödematöser Lidschwellungen.

Morbus Morbihan is a rare disease characterized by persistent erythema and edema of the central and upper half of the face, mainly restricted to the forehead, glabella, eyelids, nose and cheeks. It is thought to be a rare complication of rosacea and may lead to fibrotic induration. The characteristic features are a typical clinical picture with histological alterations. Diagnosis and treatment are difficult because of the absence of specific laboratory findings and in most cases resistance to clinical therapy.We report the first case of morbus Morbihan in the ophthalmic literature. A 53-year-old woman complained of erythematous and edematous eyelids which caused a significant visual field defect for 4 years. The typical clinical picture, histological findings and the exclusion of several differential diagnoses led to the diagnosis of morbus Morbihan. Oral rosacea treatment did not result in any improvement, therefore, eyelid reduction surgery followed by lymphatic drainage was performed. Apart from cosmetic improvement a significant reduction of visual field defects was observed postoperatively.

[New options of high resolution optical coherence tomography in glaucoma diagnostic]. / Neue Möglichkeiten der hochauflösenden optischen Kohärenztomographie in der Glaukomdiagnostik.

At present time domain optical coherence tomography (TD-OCT) plays a less important role in glaucoma diagnostics and is used mainly for macula diagnostics. The Fourier domain optical coherence tomography (FD-OCT) with enhanced resolution has new options to detect glaucoma changes. This new technology is referred as frequency domain or spectral domain OCT. This paper will present current and new options of OCT in glaucoma diagnostics. Measurements of the optic nerve head and the retinal nerve fiber layer thickness using this new technology have been shown to be reproducible. Devices which use TD-OCT (e.g. Stratus-OCT) have a lower resolution than devices that use FD-OCT (e.g. RTVue-100; 10 microm versus 5 microm axial resolution). A new option is the evaluation of the retinal ganglion cell complex. The measurement of the optic nerve head and the retinal nerve fiber layer using FD-OCT are promising for glaucoma diagnostics. How this new technology, especially the ganglion cell complex analysis is comparable to other technologies and whether it is helpful for glaucoma diagnostics and monitoring of management will be evaluated in future studies.

[Measuring intraocular pressure by different methods]. / Messung des Augeninnendrucks (Tonometrie) mit unterschiedlichen Verfahren.

Tonometry is the measurement of intraocular pressure (IOP). Normal IOP values range from 10 to 21 mmHg (15.5 mmHg+/-2 SD). They are influenced by various factors, including the patient's position during measurement, central corneal thickness, corneal diameter and curvature, rigidity of the cornea, and the cornea's state of hydration. Until now, Goldmann applanation tonometry has been seen as the gold standard for intraocular pressure measurement. But many new techniques and devices for determining IOP have been developed, such as noncontact tonometry, the Tono-Pen, the ICare tonometer, dynamic contour tonometry, TGDc-01 tonometry, and the ocular response analyzer. The aim of these techniques is to minimize distorting influences to obtain the "true IOP." Several of these methods show advantages in specific situations; however, limitations exist that should be considered when interpreting the obtained IOP results. This article describes the individual methods of measurement and discusses their advantages and disadvantages.

[Frequency-doubling technology : A new method for determining glaucomatous visual field defects]. / Frequenzverdopplungsperimetrie : Neue Methode zur Untersuchung glaukomatöser Gesichtsfeldausfälle.

Glaucoma is a disease in which death of retinal ganglion cells is associated with loss of visual function. The gold standard for visual field testing has been standard automated perimetry (SAP). However, up to 30-50% of retinal ganglion cells must be lost before a scotoma is detected with SAP. Therefore, investigators have been interested in finding diagnostic techniques that would allow earlier detection of visual field loss than that detected by standard white-on-white perimetry. Frequency-doubling technology (FDT) has been suggested as a promising technique that may detect glaucomatous ganglion cell damage earlier than SAP by targeting a sparsely spaced subsystem of Mgamma retinal ganglion cells where cell damage is less masked by redundancy. The second generation of FDT perimetry, the Matrix FDT, was released with the intention of improving the spatial resolution of visual field defects. In this article we present FDT and discuss data that compare FDT with standard white-on-white perimetry.

[Glaucoma diagnosis and follow-up using the Heidelberg Retina Tomograph]. / Glaukomdiagnostik und Verlaufskontrolle mit dem Heidelberg Retina Tomograph.

The Heidelberg Retina Tomograph (HRT) is a glaucoma diagnosis system that provides fast, noninvasive topographic information about the optic nerve head, the neuroretinal rim, and the thickness of the nerve fiber layer. With these capabilities, it is one of the leading laser systems for detecting glaucoma. Statistical methods such as the Moorfields regression analysis and the glaucoma probability score, as well as discriminant functions implemented in the instrument, support the clinician in discriminating between glaucoma and healthy eyes. The primary method for assessing glaucomatous change using the HRT is topographic change analysis, a technique that compares the variability within a baseline examination to that between baseline and follow-up examinations. The stereometric trend analysis reports changes in normalized topographic parameters over time. Furthermore, the flicker comparison enables the detection of small topographic changes over time. The use of HRT does not replace clinical examination but facilitates the assessment and management of glaucoma according to the observer's experience.

[Complications after laser in situ keratomileusis (LASIK): results of a meta-analysis on incidences and expectable costs]. / Komplikationen nach Laser-in-Situ-Keratomileusis (LASIK): Ergebnisse einer Metaanalyse zu Inzidenzen und Folgekosten.

PURPOSE: Laser in situ Keratomileusis (LASIK) is considered to be safe and effective for the treatment of moderate myopia. Nevertheless, the treatment can result in complications, associated with additional costs for treatment of the latter and an associated reduction of the primary treatment's overall cost efficiency. METHODS: To both identify clinically relevant LASIK-associated complications and to estimate their expectable incidence and treatment cost-profile, a quantitative meta-analysis of trial publications between 1995 - 2004 was implemented. Inclusion criteria were a minimum sample size of 25 eyes, a reported preoperative patient refraction between - 1 und - 14 dioptres and the documentation of an at least 6 months recall period. For each reported complication its "meta incidence" (point estimate and 95 % confidence interval) was estimated. Furthermore, for each complication a clinical pathway for its treatment was modelled assuming a worst case scenario; the treatment costs for this pathway were simulated. The resulting costs for the treatment of one complication were then averaged by the expectable incidence of the respective complication; the maximum "expectable" costs for the respective complication's treatment were then summed up to correct the overall LASIK direct costs. RESULTS: A total of 30 trial reports was included into the meta-analysis; in total, 21 clinically relevant complications were identified (31 % intraoperative complications, among which 19 % were microkeratome-associated, versus 69 % postoperative complications, among which 87 % were classified as long-term postoperative). The most frequent complication was "light sensations" with a meta incidence of 46 % (95 % confidence interval 42 - 50 %), the most cost intensive complications were those requiring clinical re-treatment (overall meta incidence 24 % and expectable cost increase of 449 euro per primary LASIK procedure). In summary the total direct costs of 2426 euro per eye for the initial LASIK procedure may be increased by a total of maximum 648.30 euro, according to a maximum "expectable" cost increase of 27 % per primary LASIK due to complications. CONCLUSION: At least the worst case scenario introduced into this investigation demonstrated an economically relevant order for the expectable LASIK complications and the associated additional costs for complication treatment.

Clinical benefit, complication patterns and cost effectiveness of laser in situ keratomileusis (LASIK) in moderate myopia: results of independent meta analyses on clinical outcome and postoperative complication profiles.

PURPOSE: Laser in situ keratomileusis (LASIK) means a patient investment of 2426 Euro per eye, which usually cannot be funded by European health care insurers. In the context of recent resource allocation discussions, however, the cost effectiveness of LASIK could become an important indication of allocation decisions. Therefore an evidence based estimation of its incremental cost effectiveness was intended. METHODS: Three independent meta analyses were implemented to estimate the refractive gain (dpt) due to conventional LASIK procedures as well as the predictability of the latter (%) (fraction of eyes achieving a postoperative refraction with maximum deviation of +/- 0.5 dpt from the target refraction). Study reports of 1995 - 2004 (English or German language) were screened for appropriate key words. Meta effects in refractive gain and predictability were estimated by means and standard deviations of reported effect measures. Cost data were estimated by German DRG rates and individual clinical pathway calculations; cost effectiveness was then computed in terms of the incremental cost effectiveness ratio (ICER) for both clinical benefit endpoints. A sensitivity analysis comprised cost variations of +/- 10 % and utility variations alongside the meta effects' 95% confidence intervals. RESULTS: Total direct costs from the patients' perspective were estimated at 2426 Euro per eye, associated with a refractive meta benefit of 5.93 dpt (95% meta confidence interval 5.32 - 6.54 dpt) and a meta predictability of 67% (43% - 91%). In terms of incremental costs, the unilateral LASIK implied a patient investion of 409 Euro (sensitivity range 351 - 473 Euro) per gained refractive unit or 36 Euro (27 - 56 Euro) per gained percentage point in predictability. When LASIK associated complication patterns were considered, the total direct costs amounted up to 3075 Euro, resulting in incremental costs of 519 Euro / dpt (sensitivity range 445 - 600 Euro / dpt) or 46 Euro / % (34 - 72 Euro / %). Most frequently reported LASIK complications were "central islands / over- / undercorrection / regression" (meta incidence estimate 24%) and "haze" (15%), which were identified by means of an independent meta analysis. CONCLUSION: Bearing incremental costs of 519 Euro per gained refractive unit in mind, the conventional LASIK procedures showed an encouraging cost effectiveness range; the latter estimate may serve as a rationale for future allocation discussions in ophthalmology.