[ChatGPT and the German board examination for ophthalmology: an evaluation]. / ChatGPT und die deutsche Facharztprüfung für Augenheilkunde: eine Evaluierung.

PURPOSE: In recent years artificial intelligence (AI), as a new segment of computer science, has also become increasingly more important in medicine. The aim of this project was to investigate whether the current version of ChatGPT (ChatGPT 4.0) is able to answer open questions that could be asked in the context of a German board examination in ophthalmology. METHODS: After excluding image-based questions, 10 questions from 15 different chapters/topics were selected from the textbook 1000 questions in ophthalmology (1000 Fragen Augenheilkunde 2nd edition, 2014). ChatGPT was instructed by means of a so-called prompt to assume the role of a board certified ophthalmologist and to concentrate on the essentials when answering. A human expert with considerable expertise in the respective topic, evaluated the answers regarding their correctness, relevance and internal coherence. Additionally, the overall performance was rated by school grades and assessed whether the answers would have been sufficient to pass the ophthalmology board examination. RESULTS: The ChatGPT would have passed the board examination in 12 out of 15 topics. The overall performance, however, was limited with only 53.3% completely correct answers. While the correctness of the results in the different topics was highly variable (uveitis and lens/cataract 100%; optics and refraction 20%), the answers always had a high thematic fit (70%) and internal coherence (71%). CONCLUSION: The fact that ChatGPT 4.0 would have passed the specialist examination in 12 out of 15 topics is remarkable considering the fact that this AI was not specifically trained for medical questions; however, there is a considerable performance variability between the topics, with some serious shortcomings that currently rule out its safe use in clinical practice.

Do biometric parameters improve the quality of optic nerve head measurements with spectral domain optical coherence tomography?

BACKGROUND: Spectral domain optical coherence tomography (SD-OCT) is a widely applied non-invasive technique for evaluating optic nerve head parameters. The aim of this study was to evaluate the impact of biometric parameters such as the spherical equivalent (SE) and the anterior corneal curvature (ACC) on the peripapillary retinal nerve fiber layer (pRNFL), Bruch's membrane opening (BMO), and the minimum rim width (MRW) measurements performed by spectral domain optical coherence tomography (SD-OCT) in glaucomatous and healthy eyes. METHODS: In this cross-sectional, case-control prospective pilot study, the glaucoma group consisted of 50 patients with previously diagnosed and treated glaucoma and one healthy group of 50 subjects. Two consecutive examinations of pRNFL, BMO, and MRW with SD-OCT for every patient were performed without ACC and objective refraction (imaging 1) and with them (imaging 2). RESULTS: The interclass correlation coefficient (ICC) reflected high agreement between imaging 1 and imaging 2 in both groups. The ICC in the glaucoma and healthy groups for pRNFL (0.99 vs. 0.98), BMO (0.95 vs. 0.97), and MRW (1.0 vs. 1.0) was comparable. CONCLUSIONS: Our preliminary data from a small number of eyes showed that the measurements of pRNFL, MRW, and BMO reflected high agreement between both imaging techniques with ACC and objective refraction and without these parameters in subjects with a refractive error up to ± 6.0 diopters. Further studies with participants with higher refractive error are necessary to evaluate the impact of biometric parameters such as SE and ACC on measurements with SD-OCT.

[Combined XEN and Baerveldt implant-principles and management of complications]. / Kombiniertes XEN-Baerveldt-Implantat ­ Prinzip und Management von Komplikationen.

The treatment of congenital glaucoma requires special expertise and often novel surgical approaches. The combined use of a XEN and a Baerveldt implant is an alternative to conventional tube implants and may be less harmful for long-term corneal endothelial damage. If this technique does not provide sufficient long-term control of intraorbital pressure (IOP), a direct implantation of the Baerveldt tube can be easily performed in a second intervention.

[Trabeculectomy with mitomycin C : Video article]. / Trabekulektomie mit Mitomycin C : Videobeitrag.

Trabeculectomy is the most proven method for the treatment of open angle glaucoma. The long-term results of this method show an 80% success rate in lowering intraocular pressure over 20 years. The surgical technique is demonstrated in detail with the help of a video of the operation and which is available online. For more than 15 years trabeculectomy has been performed with the use of antifibrotic substances, such as mitomycin C. Long-term treatment with antiglaucoma eyedrops leads to a proven inflammation of the conjunctiva and the ocular surface with an increase in lymphocytes, mast cells, and fibroblasts. Discontinuation of antiglaucoma therapy in turn allows regeneration of the ocular surface. From the knowledge gained from these histopathological studies it has been recommended to stop glaucoma treatment prior to glaucoma surgery and to pretreat the conjunctiva with eyedrops containing cortisone. Administration of nonsteroidal antiphlogistic substances or local steroids to the conjunctiva 4 weeks prior to surgery increases long-term success of the filtering bleb function.

Revision of encapsulated blebs after trabeculectomy: Long-term comparison of standard bleb needling and modified needling procedure combined with transconjunctival scleral flap sutures.

PURPOSE: To compare two surgical approaches for treating encapsulated blebs after trabeculectomy with mitomycin C, in terms of the development of intraocular pressure and progression of glaucoma in a long-term follow up: 1. bleb needling alone vs. 2. a combined approach of needling with additional transconjunctival scleral flap sutures, to prevent early ocular hypotony. METHODS: Forty-six patients with failing blebs after trabeculectomy with mitomycin C were enrolled in this study. Patients received either needling revision alone (group 1; n = 23) or a combined needling with additional transconjuctival flap sutures, if intraoperatively the intraocular pressure was estimated to be low (group 2; n = 23). Intraocular pressure (IOP), visual acuity, visual fields, and optic nerve head configuration by means of Heidelberg Retina Tomograph (HRT®) were analysed over time. Results from both groups were compared using Mann-Whitney U-test for single timepoints. RESULTS: IOP did not differ significantly between the two groups during follow-up at three months (P = 0.13), six months (P = 0.12), one year (P = 0.92) and two years (P = 0.57) after surgery. Furthermore, there was no significant difference in the course of glaucoma concerning the optic nerve anatomy between the two groups (Rim Area Change in the Moorfields Regression Analysis of HRT®) till two years after surgery (P = 0.289). No functional impairment in visual acuity and visual fields was found in the groups of the study. CONCLUSIONS: Single needling procedure is a standard successful method for restoring the function of encapsulated blebs. Postoperative hypotony represents a possible hazard, which can be minimized by additional transconjunctival flap sutures. Long-term results suggest that this modification is equally effective in lowering the IOP and preventing the progression of glaucoma as the standard needling procedure. To our knowledge this is the first study to investigate the long-term effect of tranconjunctival sutures for the prevention of hypotony.

[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.

[Value of Heidelberg retinal tomography in glaucoma diagnostics]. / Stellenwert der Heidelberg-Retina-Tomographie in der Glaukomdiagnostik.

BACKGROUND: The Heidelberg retinal tomography (HRT) is a technique that has been used for more than 20 years for glaucoma diagnostics and management. Many hundreds of scientific investigations have tested the reliability and accuracy of HRT for the early diagnosis of glaucoma and just as many studies can be found on the detection of progression in glaucoma. It is still one of the leading imaging systems for the detection and follow-up of glaucoma. Hardware and statistical methods implemented for progression detection have been regularly updated by the company and internationally known glaucoma specialists. METHODS: Besides the analysis of stereometric parameters and trend analyses, the primary method for assessing glaucomatous change using the HRT is the topographic change analysis (TCA), a technique that compares the variability within a baseline examination to that between baseline and follow-up examinations.Furthermore, the flicker comparison enables detection of small topographic changes over time. CONCLUSION: The use of HRT does not replace clinical examinations but facilitates the assessment and management of glaucoma depending on observer experience. This imaging method will still have a significant value in the future for glaucoma diagnostics, with a special emphasis on assessment of progression.

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.

[Optical coherence tomography (OCT) in glaucoma diagnostics]. / Stellenwert der optischen Kohärenztomografie (OCT) für die Glaukomdiagnostik.

Optical coherence tomography (OCT) provides high resolution objective and quantitative measurements of the optic disc parameters and RNFL thickness and has been widely used for detection of glaucomatous damage and disease progression. The recent introduction of spectral domain (SD)-OCT technology, also known as Fourier domain (FD)-OCT offers significant advantages over the previous time domain (TD)-OCT, allowing 3 D imaging of the retina and optic disc with ultra-high acquisition speed and ultra-high resolution. The higher resolution of (SD)-OCT offers enhanced visualisation and improved segmentation of the retinal layers, providing a higher accuracy in identification of subtle changes of the optic disc and RNFL thinning associated with glaucoma.

[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 using scanning laser polarimetry]. / Glaukomdiagnostik mittels Scanning-Laser-Polarimetrie.

Scanning laser polarimetry (SLP) is another technology for early glaucoma diagnosis. This technique (represented in the GDx from Carl Zeiss Meditec, Jena, Germany) is based on polarimetry and measures the retinal nerve fiber layer (RNFL) thickness. Compared with previous instruments without customized corneal compensation, the variable corneal compensation technology enables improved differentiation between glaucoma and healthy eyes. Limitations are the atypical birefringence patterns that exist in some eyes, showing false high RNFL values. The newest software uses enhanced corneal compensation (ECC) technology to avoid these atypical patterns and to improve glaucoma diagnosis. Advantages of SLP include independence from drawing a contour line and a reference plane. Follow-up using SLP is limited, but with the use of the new ECC technology, trend and event analyses are possible. Long-term studies will determine the effectiveness of this method.

[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.

[Optic disc photography and retinal nerve fiber layer photography]. / Papillenfotografie und retinale Nervenfaserschichtfotografie.

In addition to optic disc assessment at the slit lamp and the use of imaging devices for glaucoma diagnosis, optic disc photography is widely used in clinical practice. The advantages of stereophotography are a permanent recording of the optic disc status especially used for serial evaluation of discs, good visibility of the peripapillary region and a relatively fast examination without pupil dilation (if using non-mydriatic fundus cameras). The limitations are the need for clear media, pupil dilation, a skilled photographer and the delay involved.Retinal nerve fiber layer (RNFL) photography is based on the absorption of green light by melanin in the retinal nerve fiber layer. In comparison to scanning laser devices this methodology is not as convenient and requires widely dilated pupils and high levels of competence by technical personnel. Furthermore, the examination with RNFL photographs requires considerable learning and experience. RNFL photography detects glaucoma damage before visual field defects occur.

Comparison of the iCare rebound tonometer and the Goldmann applanation tonometer over a wide IOP range.

BACKGROUND: The aim of this study was to compare the intraocular pressure (IOP) results measured by the iCare rebound tonometer with those obtained by the Goldmann applanation tonometer (GAT) over a wide range of IOP values. Furthermore, the comfort level of the iCare measurement was evaluated. METHOD: The study included 75 eyes of 75 patients. The patients were divided into three groups (7-15 mmHg n = 25, 16-22 mmHg n = 25, 23-60 mmHg n = 25). The measurements were taken by two independent observers in a masked fashion. All patients were asked about discomfort during the iCare measurement. To establish the agreement between the two devices, a Bland-Altman analysis was performed. RESULTS: Overall, the 95% confidence interval of the differences between the two devices was -8.67 to 10.25 mmHg and in 62.7%, the iCare measurement was within +/-3 mmHg of the GAT measurements. The distribution of the differences in IOP was similar, from 7-22 mmHg. In the higher IOP range (23-60 mmHg), however, the deviation was almost twice as large. The measurement with the iCare tonometer was well tolerated; 100% of the patients denied any discomfort. CONCLUSIONS: The iCare tonometer is a mobile alternative to GAT in a low to moderate IOP range, but our findings show a greater deviation than previously reported. In high IOP values, measurements with the iCare tonometer do not correlate well with GAT.

Results of a screening programme to identify plants or plant extracts that inhibit ruminal protein degradation.

One aim of the EC Framework V project, 'Rumen-up' (QLK5-CT-2001-00 992), was to find plants or plant extracts that would inhibit the nutritionally wasteful degradation of protein in the rumen. A total of 500 samples were screened in vitro using 14C-labelled casein in a 30-min incubation with ruminal digesta. Eight were selected for further investigation using a batch fermentation system and soya protein and bovine serum albumin as proteolysis substrates; proteolysis was monitored over 12 h by the disappearance of soluble protein and the production of branched SCFA and NH3. Freeze-dried, ground foliage of Peltiphyllum peltatum, Helianthemum canum, Arbutus unedo, Arctostaphylos uva-ursi and Knautia arvensis inhibited proteolysis (P < 0.05), while Daucus carota, Clematis vitalba and Erica arborea had little effect. Inhibition by the first four samples appeared to be caused by the formation of insoluble tannin-protein complexes. The samples were rich in phenolics and inhibition was reversed by polyethyleneglycol. In contrast, K. arvensis contained low concentrations of phenolics and no tannins, had no effect in the 30-min assay, yet inhibited the degradation rate of soluble protein (by 14 %, P < 0.0001) and the production of branched SCFA (by 17 %, P < 0.05) without precipitating protein in the 12-h batch fermentation. The effects showed some resemblance to those obtained in parallel incubations containing 3 mum-monensin, suggesting that K. arvensis may be a plant-derived feed additive that can suppress growth and activity of key proteolytic ruminal micro-organisms in a manner similar to that already well known for monensin.

Glaucoma detection using the GDx nerve fiber analyzer and the retinal thickness analyzer (RTA).

PURPOSE: To compare the ability of the nerve fiber analyzer (GDx) and the retinal thickness analyzer (RTA) to discriminate between glaucomatous and healthy eyes. METHODS: Thirty-seven glaucoma patients (early to moderate severity) and 34 healthy controls were included. Glaucoma patients were defined as those with two repeatable abnormal visual fields by automated perimetry within 1 year. All subjects were examined with a GDx scanning laser polarimeter and RTA. Twelve GDx retinal nerve fiber layer parameters and 12 RTA optic disk topography parameters were obtained. GDx and RTA measurements were compared between both experimental groups using t-tests. Areas under the receiver operating characteristic curves (AUROC) for discriminating between healthy and glaucomatous eyes using GDx and RTA parameters were calculated and compared, and sensitivities at >or=80% and >or=95% specificity were reported. RESULTS: Statistically significant differences between glaucomatous and healthy eyes were found for most GDx and RTA parameters. For GDx, the parameter with the largest AUROC for discriminating between healthy and glaucomatous eyes was the number (AUROC = 0.91, sensitivity = 85% at specificity = 84%, sensitivity = 73% at specificity = 95%). For RTA, the parameter with the largest AUROC was mean cup depth (AUROC = 0.79, sensitivity = 61% at specificity = 82%, sensitivity = 33% at specificity = 95%). The AUROC for the GDx number was significantly larger than the AUROC for RTA mean cup depth (p<0.05). CONCLUSIONS: GDx showed better discrimination and better sensitivities at fixed specificities than RTA. The currently available RTA optic disk analysis software likely cannot replace GDx RNFL analysis software for successful glaucoma diagnosis.

[Goldmann applanation tonometry and dynamic contour tonometry. Comparison of intraocular pressure measurements in the course of product certification according to EN ISO 8612:2001]. / Goldmann-Applanationstonometrie und dynamische Konturtonometrie. Vergleich der intraokularen Druckmessung im Rahmen einer Typprüfung nach EN ISO 8612:2001.

BACKGROUND: The aim of the study was to compare intraocular pressure (IOP) measurements between Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT) during product certification according to the international requirements for ophthalmic instruments (tonometers, ISO 8612:2001). METHODS: The study included 160 eyes of 80 subjects. IOP measurements were performed four times consecutively on each instrument in randomized order. The difference of mean IOP measurements between GAT and DCT was analyzed. Furthermore, Bland and Altman analysis was performed to assess agreement between the instruments. RESULTS: The mean difference between DCT and GAT IOP measurements was 0.30+/-2.18 mmHg. At low to normal IOP values of 7-16 mmHg and higher IOP values of > or =23 mmHg, the difference between DCT IOP measurements and GAT IOP measurements increased in the opposite direction (1.44+/-1.59 mmHg and -1.47+/-2.57 mmHg). The Bland and Altman analysis revealed a fixed bias of -0.4+/-2.0 mmHg. CONCLUSIONS: The test tonometer DCT exceeds the requirements for the international standard for tonometers ISO 8612:2001. The results are valid for a central corneal thickness of 540+/-40 microm.