Automatic inference of ICD-10 codes from German ophthalmologic physicians' letters using natural language processing.

Physicians' letters are the optimal source of diagnoses for registries. However, most registries demand for diagnosis codes such as ICD-10. We herein describe an algorithm that infers ICD-10 codes from German ophthalmologic physicians' letters. We assess the method in three German eye hospitals. Our algorithm is based on the nearest-neighbor method as well as on a large thesaurus for ICD-10 codes. This thesaurus was embedded into a Word2Vec space created from anonymized physicians' reports of the first hospital. For evaluation, each of the three hospitals sent all diagnoses taken from 100 letters. The inferred ICD-10 codes were evaluated for correctness by the senders. A total of 3332 natural language terms had been sent in (812 hospital one, 1473 hospital two, 1047 hospital three). A total of 526 non-diagnoses were excluded upfront. 2806 ICD-10 codes were inferred (771 hospital one, 1226 hospital two, 809 hospital three). In the first hospital, 98% were fully correct and 99% correct at the level of the superordinate disease concept. The percentages in hospital two were 69% and 86%. The respective numbers for hospital three were 69% and 91%. Our simple method is capable of inferring ICD-10 codes for German natural language diagnoses, especially when the embedding space has been built with physicians' letters from the same hospital. The method may yield sufficient accuracy for many tasks in the multi-centric setting and can easily be adapted to other languages/specialities.

[Early diagnosis of keratoconus]. / Frühdiagnose des Keratokonus.

Keratoconus is morphologically associated with increasing deformation, thinning and scarring of the cornea. This functionally leads to refractive changes and visual deterioration. In the early stages there are often no clear clinical signs in the slit-lamp examination; however, confirming the diagnosis as early as possible is important in order to provide patients with an appropriate treatment. For the early diagnosis of keratoconus, various diagnostic devices have been introduced in recent years and decades. These include keratometry with reflection-based or elevation-based systems and optical coherence tomography. High-frequency ultrasound microscopy and corneal biomechanics can also be used to establish the diagnosis of keratoconus by the measurement of other parameters. The necessity and the available possibilities for early diagnosis of keratoconus are presented in more detail in this article.

[Acute angle closure : An ophthalmological emergency in the emergency room]. / Akuter Winkelblock : Ein ophthalmologischer Notfall in der medizinischen Notaufnahme.

BACKGROUND: The symptoms of acute angle closure, an emergency event that can lead to irreversible blindness without timely treatment, are diverse. Initially, these can be interpreted as internal or neurological diseases if headaches, pupil rigidity or nausea are in the foreground. The aim of our study was to assess the rate of harming and invasive diagnostics after primary presentation of patients with acute primary angle closure to nonophthalmologists. METHODS: Retrospective single center study of patients with acute primary angle closure. To analyze these patients, all patients who were treated by surgical iridectomy (5-133.0) or iridotomy by laser (5-136.1) in the period 2014-2018 at the Eye Center at Medical Center, University of Freiburg (Germany), were identified. Subsequently, data analysis was carried out through file inspection to check the inclusion and exclusion criteria and the course of the disease. RESULTS: In total, 91 patients with acute primary angle closure were included. Of these, 28% (n = 25) initially presented to nonophthalmological disciplines. In this patient group 56% (n = 11) received nontargeted diagnostics, with cranial imaging in 32% (n = 8) and lumbar puncture in 8% (n = 2). CONCLUSION: Acute primary angle closure is associated with a high rate of nontargeted diagnostics by nonophthalmologists. Therefore, the clinical picture of acute angle closure should be in mind across all disciplines. With unspecific symptoms such as headaches, nausea and vomiting as well as pupil rigidity, the possibility of an acute increase in intraocular pressure caused by acute angle closure must be considered and early consultation with an ophthalmologist is recommended.

Long-term follow-up of intraocular pressure and pressure-lowering medication in patients following Excimer laser trabeculotomy.

BACKGROUND: Excimer laser trabeculotomy (ELT) is a minimally invasive procedure to lower the intraocular pressure (IOP) via a photo-ablative laser that is applied to the trabecular meshwork. With this procedure, it is possible to improve the outflow of the aqueous humor. Until now, a limited number of studies examining mostly relatively small sample sizes with midterm follow-up exist. We therefore present the analysis of a large ELT cohort in a long-term follow-up. METHODS: We recorded data from 580 patients who underwent ELT or combined ELT with cataract surgery at our institution from November 2000 until March 2011. A total of 512 patients with primary open angle glaucoma (POAG), pseudoexfoliation glaucoma (PEX), and ocular hypertension (OHT) were included in the analysis. At every follow-up examination, the usage of IOP-lowering medication and the IOP were recorded. Failure criteria were defined as the need for another surgical glaucoma procedure, when the IOP was not 21 mmHg or less and a reduction of 20% from the baseline was not achieved with (qualified success) or without (absolute success) additional medication. Statistical analysis was done using Kaplan-Meier analysis and Cox regression. RESULTS: Four hundred twenty-eight patients underwent combined cataract and ELT surgery, and 84 underwent solitary ELT surgery. After a median follow-up time of 656 days, 87% (combined surgery) and 66% (ELT) of the patients did not have to undergo another IOP-lowering intervention; 47/31% were classified as a qualified success and 31/11% as a complete success. The IOP-lowering medication, however, could not be significantly reduced within that time period. CONCLUSION: Especially when combined with cataract surgery, ELT is a feasible minimally invasive procedure to lower the IOP on a mid- to long-term basis. Over the long term, however, IOP-lowering medication could not be reduced.

Toric IOL positioning with a no-touch head-up display axis alignment.

PURPOSE: To compare a new no-touch alignment technique for toric intraocular lenses (IOL) with the conventional technique that uses a manual pendulum. METHODS: In this retrospective case-control study, patients who underwent toric IOL implantation using two different alignment techniques (digital Callisto® system vs. manual-pendulum-based marking) were compared in a vector analysis using the Alpins method and an analysis of variance regarding corrected and uncorrected visual acuity and the deviation of the achieved IOL axis from the targeted axis. RESULTS: Sixty-one eyes were included into analysis. Thirty-six of these surgeries were performed via the Callisto® system and 25 eyes via pendulum-based corneal markings. Median IOL axis misalignment was 3° in both groups. Median uncorrected distance visual acuity was 0.097 logMAR versus 0.200. Median best-corrected visual acuity was 0.000 logMAR versus 0.097. All these data were below the range of statistical significance (p > 0.05). Vector analysis showed no significant difference for TIA [median of 3.14 diopters (D) vs. 2.73 D], SIA (median of 3.82 D vs. 3.79 D), DV (1.18 D vs. 1.08 D), and CI (1.23 vs. 1.29). Median angle of error was 1.96° versus - 0.44° (p > 0.05). CONCLUSIONS: We found no significant difference in the refractive results, the IOL positioning, and the best-corrected and uncorrected distance visual acuity between the two compared methods. Nevertheless, the Callisto® IOL alignment system delivers a standardized and easy-to-use technology. In particular, less-experienced surgeons might benefit from this marking technique.

[Keratoplasty in children : Indications and results]. / Keratoplastik bei Kindern : Indikationen und Ergebnisse.

Penetrating keratoplasty in children is associated with very specific difficulties for the surgeon as well as for the patient and the parents. Special features are specific pediatric indications, which do not occur in adults, a more difficult examination and treatment adherence depending on the parents. Diseases with a favorable prognosis include keratoconus and herpetic keratitis. Especially sclerocornea and the Peters' anomaly often have a limited prognosis regarding vision and graft survival due to secondary malformations of the eye. In addition, younger age represents a risk factor. This is most likely due to the impaired examination during follow-up and reduced compliance. For successful penetrating keratoplasty in children the timing for the operation, in which the risk for the graft is weighed up against the risk for amblyopia, is crucial.

Intraocular pressure measurement with Corvis ST in comparison with applanation tonometry and Tomey non-contact tonometry.

PURPOSE: Intraocular pressure (IOP) measurement can be performed with different methods. Newer methods have to be compared to the standard method, the Goldmann applanation tonometry (GAT). We herein compare two air-puff tonometers, the non-contact tonometer (Tomey NCT) and the Corvis ST (CST) with GAT in eyes with a broad spectrum of IOP. METHODS: Two hundred and forty-nine eyes of 249 patients (with diagnosis of either glaucoma or ocular hypertension) were included in this monocenter prospective cohort study. Each eye underwent IOP measurements via GAT, NCT and CST. Bland-Altman plots were calculated to compare the different methods in the three groups. Paired t tests were used for statistical comparison between the three measurement methods. The difference between the different methods was tested on correlation against central corneal thickness (CCT). RESULTS: Mean IOP in GAT was 17.6 mmHg (standard deviation (SD) 5.9), 16.3 mmHg (SD 5.6) in NCT and 18.0 mmHg (SD 5.5) in CST. Comparisons between GAT and CST vs. NCT showed significant differences (p < 0.001), while GAT vs. CST showed no significant difference (p = 0.1162). Mean CCT was 538.7 µm (SD 35.1). CONCLUSIONS: Mean values of GAT and CST show comparable results. However, both GAT and CST differ significantly from NCT. NCT shows lower IOP values compared to both other methods.

[Scleral melting after cyclophotocoagulation]. / Skleraeinschmelzung nach Zyklophotokoagulation.

We report on a case of a scleral melting as a rare but severe complication of transscleral cyclophotocoagulation. The tissue defect was successfully repaired by tectonic keratoplasty.

[Work sampling in ophthalmological clinical studies. A multicenter field study]. / Zeiterfassung in ophthalmologischen klinischen Studien. Eine multizentrische Feldstudie.

BACKGROUND: Work in clinical studies is generally more elaborate and therefore more time-consuming in comparison to the clinical routine. The purpose of this study was to systematically investigate the time consumption in the German ophthalmological clinical trial centers. METHODS: The members of the working group of the German Ophthalmology Society clinical study centers (Arbeitsgemeinschaft DOG Klinische Studienzentren) were asked to fill in three questionnaires about best estimations for the time spent on study-related procedures and administration. Additionally, work sampling was performed for each employee at each study center over a period of 3 weeks. RESULTS: The questionnaires were completed by 9 of the 11 centers. Overall, 5504 working hours were recorded. On an average working day, the time spent for both documentation and administration averaged 4 h each. Operative interventions consumed a significant amount of time (2.8 h), as did ophthalmological examinations (2.5 h) and obtaining informed consent (1.5 h). The recorded time consumption for visual acuity testing, informed consent and documentation was well aligned with the best estimates of the three questionnaires. By contrast, interventions, ophthalmological examinations and biomaterial sample handling were underrated in the best estimations. DISCUSSION: A considerable amount of time in clinical studies is spent on documentation and administration. From work sampling, ophthalmological examinations and biomaterial sampling turned out to be surprisingly time consuming. This is probably due to preparation and postprocessing tasks. It is important to consider this when calculating the overall costs of a clinical study. In addition, many administrative activities cannot be attributed to specific patients and can therefore not be compensated on the basis of case payments alone. Additional remuneration is required to fully cover the costs in an ophthalmological study center.

Bleb-related infections and long-term follow-up after trabeculectomy.

PURPOSE: Bleb-related infections are serious complications after trabeculectomy. They can be limited to the bleb or disseminate and lead to endophthalmitis. We herein report on all bleb-related infections that have been diagnosed at the Eye Center of the University of Freiburg, Germany, since 1999. METHODS: We reviewed a total of 1816 consecutive trabeculectomies that were performed at our hospital between the years 1999 and 2014 (353 without and 1463 with intraoperative application of mitomycin C). All bleb-related infections that were diagnosed at our clinic during the same period were included in the analysis. We fitted a Cox proportional hazards model to characterize risk factors for bleb-related infections. RESULTS: We diagnosed a total of 19 bleb-related infections in this period. Three patients with bleb-related infections that came to our clinic had their trabeculectomy performed elsewhere. The overall percentage of bleb-related infections was 0.1% after 2 years (Kaplan-Meier estimate at median follow-up). Nine eyes suffered from only localized infection of the bleb. Seven eyes developed endophthalmitis. Four infections occurred during the first postoperative month. The median age on the day of diagnosis was 71 years; the median age at surgery was 69 years. In the Cox model, intraoperative application of mitomycin C and a fornix-based conjunctival flap were identified as significant risk factors (hazard ratio: 79.02, 4.69; p < 0.01, p < 0.01). The whole group showed a reduction of visual acuity in the median from logMAR 0.12 to 0.2. Eyes that suffered from endophthalmitis showed a loss from 0.3 to 0.96, while the localized infections had a reduction from 0.04 to 0.07. CONCLUSION: Bleb-related infections are a rare complication following trabeculectomy and can be localized on the bleb or can lead to endophthalmitis, thereby threatening visual acuity. The risks and benefits of mitomycin C-augmented trabeculectomies should be taken into consideration.

[Pathogenesis and diagnostic evaluation of Fuchs' endothelial corneal dystrophy]. / Pathogenese, Diagnose und Klinik der Fuchs-Endotheldystrophie.

BACKGROUND: Following new treatment options for Fuchs' endothelial corneal dystrophy, our understanding of optical and structural changes in the patient's cornea is also starting to improve. OBJECTIVE: To provide an update on clinical evaluation of Fuchs' dystrophy. MATERIAL AND METHODS: Standardized approaches to evaluate patients with Fuchs dystrophy in routine practice and research are discussed, accounting for the progressive and partially irreversible structural changes in all corneal layers. RESULTS: Early structural changes in the cornea can be detected before clinical edema becomes visible on slit-lamp exam. Optical limitations resulting from these structural changes can be quantified not only with high-contrast acuity but also with glare or contrast sensitivity tests. Characteristic vision-related limitations of patients with Fuchs dystrophy can, e.g., be assessed with V-FUCHS, a Fuchs dystrophy-specific "Visual Function and Corneal Health Status" instrument for patient-reported outcomes. CONCLUSION: Clinical grading of Fuchs dystrophy in an edematous and a non-edematous stage is outdated. Better therapy options and our improved understanding of progressive changes in the entire cornea require a standardized assessment of optical and structural changes and patient-reported limitations.

[Long-term prognosis of Peters anomaly]. / Langzeitprognose der Peters-Anomalie.

BACKGROUND: Peters anomaly normally presents in early childhood. Common features are central corneal opacities and dysgeneses of the anterior eye segment. Early surgery is commonly warranted to prevent deep amblyopia or because of severe glaucoma. We herein present the clinical outcomes of all patients treated in the Eye Center of the Albert Ludwigs University of Freiburg since 2005. Emphasis is placed on the Peters subtype. METHODS: Data were collected retrospectively by means of chart review. Kaplan-Meier analyses were used to estimate visual prognosis, the indication for keratoplasty, and the incidence of retinal detachment. RESULTS: A total of 23 patients were identified. Subtype distribution was 40% type 1, 50% type 2, and 10% Peters plus syndrome. Ten patients were female (45%). Mean age at first presentation was 5 years; mean follow-up period censored in terms of eyeball preservation was 2 years (0 months-8 years). At mean follow-up, 40.5% of all patients had undergone at least one keratoplasty (up to six per eye); 43% had undergone glaucoma surgery (cylophotocoagulation, trabeculectomy, implants) at this time. Important complications were retinal detachment (31%) and phthisis bulbi (15%). After 4 years, visual acuity in the better eye was at most 0.05 in every second patient. CONCLUSION: Prognosis of visual acuity in Peters anomaly is poor. It is generally not possible to restore visual function in the long run, i. e., reading-grade visual acuity is rarely achieved. Surgical interventions are associated with a high risk of severe complications. Therefore, the young patients should be connected to institutions for visually impaired persons at an early stage.

[Keratoplasty in Children and Adolescents]. / Keratoplastiken im Kindes- und Jugendalter.

BACKGROUND: The conditions for long-term graft survival in infants and children are unfavorable, due to the different immunological features, the impaired clinical examination and the reduced compliance and treatment adherence. However, penetrating keratoplasty is often the only option to prevent amblyopia and there may be no alternative. We examined the different indications, graft survival and complications in two specialised centres. MATERIAL AND METHODS: We identified all patients who were under the age of 18 years at the time of their penetrating keratoplasty. We then assessed the electronic file on indications, graft failure, visual acuity, enucleation and further complications. RESULTS: A total of 104 eyes of 95 patients (54 % female) were identified. Median age at the time of surgery was 14 years (quartiles 8 and 16 years). Median follow-up was 2.7 years. The following indications were identified: keratoconus (39 %), penetrating injury (18 %), non-herpetic corneal scars (12 %), herpetic corneal scars (6 %), sclerocornea (3 %), chemical burn (3 %) and miscellaneous indications (19 %). Clear graft survival according to the Kaplan-Meier method ranged from 100 % (keratoconus) to 35 % (sclerocornea). Enucleation was only necessary in patients with penetrating injuries (n = 2). Kaplan-Meier analysis estimated the failure of all grafts after one year in infants. In older patients, 90 % of grafts were still clear at that time. CONCLUSION: Prognosis of penetrating keratoplasty in children is related to the indication, and therefore the underlying disease, as well as the patients' age. In particular, infants exhibited poor prognosis, with only a very short period of clear graft survival. In indications, keratoconus showed the best prognosis, whereas sclerocornea and penetrating injuries had the worst prognosis.

[Chemokines in ophthalmology]. / Chemokine in der Augenheilkunde.

Chemokines are chemotactically active cytokines, which coordinate the distribution of immune cells within the body and also regulate the migration of leukocytes in malignant and inflammatory processes. Chemokines are a heterogeneous group of short-chain proteins that are divided into different subgroups on the basis of their structure. In addition to the chemokines (ligands) various chemokine receptors also exist. The chemokine system is given its complexity by the high redundancy of ligand-receptor interactions: one single ligand can bind to different receptors and a single receptor can interact with different ligands. In terms of receptors, distinct immune cell types have characteristic receptor expression patterns, which can be used for the immunological characterization of leukocytes. Important basic research is currently leading to a better understanding of the chemokine system. The essential importance of the chemokine system in various diseases of the anterior and posterior eye segments is becoming increasingly apparent. The following synopsis explains the individual clinical aspects as well as the underlying scientific work in the context of "chemokines in ophthalmology".

[Good practice procedures for acquisition and preparation of cryopreserved human amniotic membranes from donor placentas]. / Gute fachliche Praxis zur Gewinnung und Herstellung von kryokonservierter humaner Amnionmembran aus Spenderplazenta.

Within the framework of obtaining a valid authorization for tissue preparation of cryopreserved human amniotic membranes at the Paul Ehrlich Institute, pursuant to § 21a paragraph 1 of the German Medicines Act (AMG), parts of the existing good practice procedures for acquisition of cryopreserved human amniotic membranes from donor placentas were reviewed and supplemented by new knowledge. The present good practice procedures were formulated in cooperation with members of the section for tissue transplantation and biotechnology of the German Ophthalmological Society. The current revised version is presented in this article.

[Blepharitis component of dry eye syndrome]. / Blepharitiskomponente des trockenen Auges.

This review contains a compilation of long-standing and more recent relevant information on chronic blepharitis, especially in the context of dry eye disease regarding epidemiology, symptoms, clinical findings and pathophysiology. Chronic blepharitis often represents the underlying cause of dry eye disease but remains undetected and untreated in many cases; however, it can be a result of (hypovolemic) dry eye disease and leads to sometimes severe corneal complications, which are illustrated by material from our own patient archives. Recent findings regarding the lipid composition in the tear film in correlation with that of Meibomian gland secretions and the hypothesis of a biofilm as the basis of chronic blepharitis as a theoretical, not yet proven addition to the previously known pathophysiological factors, are discussed.

[Ophthalmological health care of the institutionalized elderly : The OVIS study]. / Ophthalmologische Versorgung in Seniorenheimen : Die OVIS-Studie.

BACKGROUND: Due to demographic change and societal transformation the number of elderly persons living in retirement homes is growing in Germany. Access to health care is more complicated in the setting of nursing homes. Different regional studies suggest unmet ophthalmological health care needs in institutionalized elderly people. This study assessed the current ophthalmological health care structure and supply status in nursing homes in Germany. METHODS: This prospective, multicenter cross-sectional study was conducted by 14 study centers in Germany. Elderly people living in 32 nursing homes were included after approval by the local institutional review boards. A standardized examination was performed which included a detailed medical and ocular history, refraction, visual acuity testing, tonometry, biomicroscopy and dilated funduscopy. Unmet ophthalmological health care needs were documented and the data were analyzed descriptively and via logistic regression modelling. RESULTS: A total of 600 participants (434 women and 166 men) aged 50-104 years were examined of which 368 (61%) had ophthalmological conditions requiring treatment. The most prevalent findings were cataracts (315; 53%), disorders of the eyelids (127; 21%), dry eye disease (57; 10%) and posterior capsule opacification (43; 7%). In 63 (11%) of the participants glaucoma was suspected and 55 (9%) of the examined population had a known diagnosis of glaucoma, of whom one third was not on any or on insufficient anti-glaucomatous therapy. 236 (39%) showed signs of age-related macular degeneration (AMD). Only 52% of the examined cohort had been examined by an ophthalmologist within the last 5 years and 39% stated that they would currently not be able to consult an ophthalmologist. Reported barriers were mainly transport and lack of support. CONCLUSION: This study demonstrates considerable unmet ophthalmological health care needs of the institutionalized elderly in Germany. Novel and reformed models of specialist care provision have to be developed.

[Riboflavin UVA crosslinking in progressive keratoconus]. / Riboflavin-UVA-Crosslinking bei progredientem Keratokonus.

In patients with keratoconus, a progressive, ectatic disease of the cornea, the shape of the cornea is continuously changing leading to a reduction in visual acuity by progressive myopia and more and more (irregular) astigmatism. The symptomatic treatment consists of the prescription of glasses or special gas-permeable rigid contact lenses. Corneal tomography is generally used for diagnosis. After initial diagnosis of keratoconus, regular tomographic follow-ups should be performed. If clinically significant progression is found and confirmed by repeated measurements, riboflavin UVA collagen crosslinking should be offered to the patients. The aim of riboflavin UVA collagen crosslinking is to halt the progression of the disease to avoid further complications. The therapeutic principle is a combined effect of the photosensitizer riboflavin and UVA light. This stiffening effect of the corneal tissue halts the progression of keratoconus. The efficacy of this treatment has been demonstrated in various randomized, controlled trials.