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.

[Photodynamic therapy in Germany-Quo vadis?] / Photodynamische Therapie in Deutschland ­ Quo vadis?

BACKGROUND: Photodynamic therapy (PDT) was originally approved for the treatment of neovascular age-related macular degeneration (nAMD) and secondary choroidal neovascularization in myopia (mCNV). In addition, it is used as an off-label treatment in patients with choroidal hemangioma, polypoidal choroidal vasculopathy (PCV), and central serous chorioretinopathy (CSC). OBJECTIVE: To track the development of PDT treatment numbers in Germany between 2006 and 2021 and to investigate the composition of the therapeutic indications. METHODS: In this retrospective study the quality reports of German hospitals were evaluated in the period from 2006 to 2019 and the number of PDTs performed was recorded. In addition, the range of indications for PDT was determined exemplarily for the Eye Center at Medical Center, University of Freiburg and the Eye Center at St. Franziskus Hospital in Münster between 2006 and 2021. Finally, the estimated prevalence of CSC and an estimate of cases requiring treatment were used to calculate the number of patients in need of PDT treatment in Germany. RESULTS: The number of PDTs performed in Germany decreased from 1072 in 2006 to 202 in 2019. While PDT was used in 86% of cases in patients with nAMD and in 7% of cases with mCNV in 2006, it was mainly performed in patients with CSC (70%) and choroidal hemangiomas (21%) from 2016 to 2021. With an estimated incidence of CSC of 1:10,000 and assuming that 16% of patients develop chronic CCS requiring treatment, approximately 1330 PDTs would need to be performed per year in Germany for patients with newly diagnosed chronic CSC alone. CONCLUSION: The decreasing numbers of PDT treatment performed in Germany is mainly due to a change to intravitreal injections as the preferred treatment for nAMD and mCNV. As PDT is currently the recommended treatment of choice for chronic CSC, an underprovision of PDT in Germany can be assumed. To enable an appropriate treatment for patients, a reliable verteporfin production, a simplified approval process by health insurance companies and a close cooperation between ophthalmologists in private practice and larger centers are urgently needed.

[Current situation of electronic medical records in ophthalmological departments in Germany]. / Status der elektronischen Dokumentation in ophthalmologischen Hauptabteilungen in Deutschland.

BACKGROUND: Electronic medical records are required in ophthalmology clinics to be integrated into digital care networks and efficient clinical registry databases. AIM OF THE WORK: To assess the prevalence and methods of electronic medical recordkeeping in inpatient ophthalmological care in Germany. MATERIAL AND METHODS: An online questionnaire was sent to all German university eye hospitals and ophthalmology departments in June 2021. It included 13 open and closed option questions concerning current practices of digital recordkeeping, including the structure of data storage and the recording of billing-relevant codes in the departments. RESULTS: A total of 44 (44%) out of 100 clinics responded. Patient documentation was completely digital in 15 (34%) clinics and partly digital and paper-based in the remaining 29 (66%). A total of 16 different constellations of documentation programs were specified. The most frequently used programs were Orbis (27%) (Dedalus HealthCare, Bonn, Germany), FIDUS (18%) (Arztservice Wente, Darmstadt, Germany), and SAP/i.s.h.med (16%) (SAP Deutschland, Walldorf, Germany; Cerner Deutschland, Berlin, Germany) and 3 clinics indicated primary use of paper records. Structured documentation of findings was performed in 61% of the departments, while 23% used a semistructured manner and 15% used a nonstructured format. Electronic documents are stored as DICOM (Digital Imaging and Communications in Medicine) documents 20% of the clinics and as PDF (Portable Document Format) files in 34% of the clinics while 23% store scanned printouts. DISCUSSION: Methods of medical record keeping in German eye clinics are heterogeneous, with paper-based documentation continuing to play an important role. This, as well as the high number of different electronic medical record software pose important challenges in terms of interoperability and secondary use of clinical data.

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.

[Technical aspects of quality assurance for intravitreal injections (IVI)]. / Technische Umsetzung der Qualitätssicherung bei der intravitrealen operativen Medikamenteneingabe (IVOM).

BACKGROUND: Successful quality assurance in intravitreal injection (IVI) of medications requires a complex information technology infrastructure. The main challenges are data availability independent of location, standardization of clinical data, integration of extensive and currently non-standardized image documentation from coherence tomography and compliance with data protection regulations. OBJECTIVE: In this article the technical implementation and data protection principles are reviewed. MATERIAL AND METHODS: Essential aspects in the implementation of quality assurance in the field of IVI are discussed in a systematic approach. RESULTS: In the field of network architectures web-based applications supplemented by local virtual private networks (VPN) and/or other software instances have recently replaced the previously commonly used physical data medium exchange. The standardization of the data, e.g. by converting the visual acuity into logMAR, plays an important role in the collection of treatment data. Multiple non-standardized data formats in optical coherence tomography complicate the general quality assurance structure and comparability of data. CONCLUSION: International standards will probably facilitate this in the near future. Until then individual solutions have to be found on site.

[Status and perspectives of registry-based studies in German ophthalmology]. / Stand und Perspektiven registerbasierter Studien in der deutschen Augenheilkunde.

BACKGROUND AND OBJECTIVE: Registry studies provide insights into real-life diagnostic and treatment data outside of clinical trials. Registry studies are interesting for quality management and explorative analyses can lead to the identification of possible risk or prognostically relevant factors and generate hypotheses. There are currently relatively few active registry studies in German ophthalmology. The aim of this survey was to collate the different infrastructure and in particular the potential hurdles in the establishment and performance of registry studies in German ophthalmology departments. METHODS: An online questionnaire collected data on participation in registry studies in German ophthalmology departments between September and December 2018. The survey was addressed to all hospital management and medical staff involved in registry studies in German ophthalmology. RESULTS: Out of 45 participants 18 were head of the department, the remaining 27 were consultants (15), medical specialists (2) and residents (10). According to the department head an average of 2.5 (2.0-3.5) employees per clinic participate in 2.0 (1.7-3.0) registry studies. The amount of reimbursement recommended by the hospital management differed significantly from the amount suggested by the staff (0.0 (0; 75) € (0-100) vs. 100.0 (50.0; 150.0) €; p = 0.0012). The most frequent hurdles to conducting a registry study were bureaucracy and limited human resources. Half of the surveyed centers profited from a separate study center and good clinical practice (GCP) courses for employees involved in studies were mandatory. A quarter of these centers received support from an IT department and/or a statistician. CONCLUSION: Registry studies are an important instrument in ophthalmology research and their importance is increasing in Germany. An agreement on national standards would make the establishment of further registry studies easier.

[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.

[3-year results of the German nationwide survey on eye injuries caused by fireworks]. / Dreijahresergebnisse der deutschlandweiten Umfrage zu Augenverletzungen durch Feuerwerkskörper.

BACKGROUND: On festive days worldwide eyes are severely injured by fireworks. The data on the number and severity are to date not registered in Germany. OBJECTIVE: How frequent are firework-induced injuries in Germany, who are the affected, how serious are the injuries, which forms of treatment are necessary and how frequent are accompanying injuries? METHOD: A German nationwide online-based survey was carried out in all inpatient eye departments and data over the last 3 consecutive years were descriptively analyzed. RESULTS: From New Years Eve 2016/2017, when 41 eye departments sent in data, the participation could be increased to 51 eye departments in 2018/2019. More than one third (33-39%) of all 1356 patients over 3 years were minors, 60% were younger than 25 years old and roughly 60% of patients were injured as bystanders or in an unclear situation. In total 25% of all eye injuries were considered severe and required inpatient treatment. Accompanying injuries of the other eye, the face and hands were more frequent in minors than in adults. Eyeball ruptures were reported in 10 minors and 38 adults over the 3 years. CONCLUSION: Particularly minors and bystanders need better protection.

Risk of aphakic glaucoma after pars plana-lensectomy with and without removal of the peripheral lens capsule.

BACKGROUND: The etiology of aphakic glaucoma is unclear. It has been suggested that remaining lens epithelium releases cytokines transducing trabecular meshwork cells. Therefore, we compared two cohorts of children undergoing lensectomy. In cohort 1, the entire lens including its capsule was removed, in cohort 2 the peripheral lens capsule was left intact, also to facilitate secondary intraocular lens implantation later on. METHODS: We included children with uni- or bilateral congenital cataract who underwent lensectomy during the first year of life with subsequent contact lenses fitting. Group 1 comprised 41 eyes, group 2 comprised 33 eyes. In group 1, the median age at surgery was 4.0 months in unilateral and 3.0 months in bilateral cases 1, in group 2, 8.1 months and 2.4 months, respectively. The mean follow-up was 12.8 years in group 1 and 9.3 years in group 2. All cases were analyzed for the prevalence of aphakic glaucoma, for visual acuity and for compliance in visual rehabilitation (contact lens/occlusion therapy). RESULTS: We found no significant difference in glaucoma prevalence between group 1 and group 2 (p = 0.68). The overall glaucoma rate was 26% after the mean follow-up of 11 years in both groups. In unilateral cases, the median visual acuity was logMAR 0.7 in both groups. In bilateral cases it was logMAR 0.4 in group 1 and logMAR 0.2 in group 2 (p = 0.05). CONCLUSIONS: Leaving the peripheral lens capsule intact had no negative effect on the incidence of glaucoma and on resulting visual acuity.

[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.

[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.

[Possibilities and Limitations of OCT-Angiography in Patients with Central Serous Chorioretinopathy]. / Möglichkeiten und Grenzen der OCT-Angiografie bei Patienten mit Chorioretinopathia centralis serosa.

Purpose Central serous chorioretinopathy (CSC) is a commonly acquired maculopathy characterized by the accumulation of subretinal fluid at the posterior pole. This study aims to analyze optical coherence tomography angiography (OCTA) findings in patients with acute and chronic CSC and to compare them to conventional imaging methods. Methods A series of 43 consecutive eyes of 29 patients diagnosed with CSC and 18 eyes of 9 healthy control subjects were included in this retrospective study. The OCTA images were assessed and compared to conventional fluorescence (FAG) and indocyanine green angiography (ICG). Results All CSC patients demonstrated abnormal areas of focal hypo- and hyperperfusion in the choriocapillaris. These were particularly evident in patients with chronic atrophic CSC. FAG and ICG imaging revealed leakage points in 10 of 43 eyes and choroidal neovascularization (CNV) in 3 of 43 eyes. OCTA imaging confirmed leakage points in 4 out of 10 cases and choroidal neovascularization in 2 out of 3 cases. In one case, OCTA demonstrated a CNV which was not detectable by FAG/ICG. Conclusion OCTA reveals areas of focal hypo- and hyperperfusion in the choriocapillaris in patients with CSC. Due to the inability to detect plasma flow, OCTA is not suitable to detect leakage points in CSC with confidence. However, OCTA reliably detects CNV in CSC even in the absence of exudative activity and may, therefore, represent an important supplement in the diagnosis of CSC.

[Bruch's Membrane Opening in OCT in Correlation with Corneal Correction - a Pilot Study]. / Abhängigkeit der Größe der OCT-Bruch-Membran-Öffnung von Hornhautkorrekturfaktoren ­ eine Pilotstudie.

Background: The measurement by optical coherence tomography (OCT) of the Bruch membrane opening (BMO) and the thinnest retinal fiber nerve layer in relation to it (BMO-MRW) has been performed in clinical routine since 2014. To compensate for astigmatism, or increased or decreased corneal power, a correction is performed through the mean K-value of the measured eye. The aim of this study was to measure the value of this correction and its influence on the measurement results. Methods: The sectors of BMO-MRW and BMO values of the five right eyes of five healthy patients were measured five times each with Heidelberg Spectralis OCT. Corneal compensation was systematically raised with each single measurement (7.1, 7.4, 7.7, 8.0, 8.3 mm). RESULTS: The data showed almost linear dependence on the given corneal compensation values, with intraindividual variability. For the BMO-MRW, only small effects of compensation were found (0.85 up to 1.97 % per K-value difference of 0.3 mm). For BMO, the effect was greater, with a mean change of 7.71 % for every 0.3 mm change in compensation. Conclusion: For BMO-MRW, corneal compensation is of low clinical relevance. BMO is more dependent on this correction. In follow-up measurements, the compensation might not account for significant changes, although we recommend using correct corneal compensation values when obtaining single or first-time measurements.

Long-term results of allogenic penetrating limbo-keratoplasty: 20 years of experience.

AimThe objective of the study was to evaluate the long-term results of allogenic penetrating limbo-keratoplasy. This method allows simultaneous transplantation of a corneal graft and limbal stem cells of the donor by means of eccentric trephination of the donor button.MethodThe data of 192 consecutive cases of allogenic penetrating limbo-keratoplasty from 1995 to 2015 were reviewed. These had been performed exclusively in eyes with complete failure of the limbal stem cells, in combination with deep corneal scarring. Indications were predominantly eye burns, inflammatory conditions, and congenital aniridia. Graft survival and rejection rates were assessed using Kaplan-Meier analysis.ResultsFollow-up averaged 2.1±2.2 years. Median graft survival was 3.4 years in eye burns, 3.9 years in inflammatory disease, and 3.2 years in congenital aniridia. Median survival was 3.9 years in the heterogenous group of other indications.ConclusionAllogenic limbo-keratoplasty is a suitable option used to treat patients with bilateral complete failure of the limbal stem cells and deep opacification of the central cornea. The main reasons for graft failure are the loss of graft-limbal stem cell functioning and endothelial graft rejection.

[Alterations in intraocular pressure and the CorVis parameters after LASIK]. / Änderung des Augeninnendrucks und der CorVis-Parameter nach LASIK.

INTRODUCTION: The reduction of corneal thickness following laser-assisted in-situ keratomileusis (LASIK) requires a correction of intraocular pressure (IOP) measurements. The corneal visualization Scheimpflug technology (CorVis ST, Oculus, Wetzlar, Germany) not only measures the IOP and central corneal thickness (CCT) but also determines 10 additional corneal parameters, such as the time to first and second applanation and velocity. Besides CCT we compared various corneal parameters before and after LASIK in order to detect possible correlations and to correct IOP measurements. METHODS: Measurements with CorVis ST were made before and after LASIK in 45 myopic patients (45 left eyes). We compared the IOP and CorVis ST parameters using a paired t­test before and after LASIK and corrected for possible correlations in a multifactorial linear model. Finally, we correlated the changes in IOP to changes in biomechanical parameters. RESULTS: We observed a direct correlation between the IOP measurements and the corneal thickness. The IOP was underestimated by 0.039 mm Hg per micrometer in reduction of corneal thickness. The multifactorial linear model showed a correlation of IOP change to A2 velocity and the radius of applanation. CONCLUSION: Surgical thinning of the central cornea via LASIK demonstrated a direct correlation between corneal thickness and IOP measurements using the CorVis ST technique. Postoperative changes of the A2 velocity and the applanation radius also had a statistically significant influence on post-LASIK IOP measurements. Our findings could be useful to obtain more precise post-LASIK IOP measurements.

[Surgical removal of Salzmann's nodules using intraoperative mitomycin C]. / Chirurgische Abtragung von Salzmann-Knoten unter Anwendung von intraoperativem Mitomycin C.

Salzmann's nodules comprise a heterogeneous group of greyish superficial corneal opacities. A substantial percentage is most likely caused by dystrophies. This could explain the recurrences after surgical removal. The Eye Center of the University Hospital Freiburg has been using mitomycin C intraoperatively during surgical removal of Salzmann's nodules since 2007 to prevent recurrences. We recently performed an uncontrolled prospective trial to evaluate this approach and also reviewed the literature. Worldwide, a total of 38 eyes have been treated with mitomycin C during surgery for Salzmann's nodules. No recurrences have been reported so far with follow-up exceeding at least 2 years in almost all eyes. No severe side effects have been observed to date. We therefore think that mitomycin C during surgery for Salzmann's nodules is advisable despite the lack of evidence from a randomized clinical trial. However, all patients must consent to the off label use of mitomycin C.

[Freiburg keratoconus registry : Example of application of smart data for clinical research and inititial results]. / Freiburger Keratokonusregister : Beispiel des Einsatzes von Smart Data zur klinischen Forschung und erste Ergebnisse.

BACKGROUND: Keratoconus is a progressive corneal disease with thinning and scarring of the cornea. Diagnostic and treatment options are usually evaluated in large prospective or retrospective trials. Big data and smart data provide the possibility to analyze routine data for clinical research. In this article we report the generation of a monocentric keratoconus registry by means of computerized data analysis of routine data. This demonstrates the potential of clinical research by means of routine data. METHODS: A "clinical data warehouse" was created from all available routine electronic data. At the time of first presentation, each eye was classified into one out of four categories: suspected, early disease, late disease and status postkeratoplasty. Through integration of multiple data sources the clinical course for each patient was documented in the registry. RESULTS: A total of 3681 eyes from 1841 patients were included. The median follow-up time was 0.54 years. Patient age was higher in the groups with more severe stages of keratoconus, the proportion of female patients was higher in the group of suspected keratoconus and patient age and male to female ratios showed statistically significant differences between the groups (p < 0.001). CONCLUSION: We were able to create a "clinical data warehouse" by linking multiple data sources and normalizing the data. With this tool we established a novel, monocentric keratoconus registry. Only the grading of disease severity and the exclusion of false positive results were carried out manually. In our opinion establishing a structured clinical data warehouse has a huge potential for clinical and retrospective studies and proves the value of the Smart Data concept.