Abstracts abgeschlossener Masterarbeiten Vision Science and Business

Author: Christine Adler

First Examiner (Aalen University): Prof. Dr. Anna Nagl

Second Examiner (Pacific University): Prof. Dr. Hannu Laukkanen

Delivery: August 31, 2025

Purpose of the Master Thesis:

The paper version of the Brain Injury Vision Symptom Survey (BIVSS) was validated in the U.S. in 2016 then widely adopted for mild to moderate traumatic brain injury (mTBI). It was later modified into unvalidated electronic formats by different providers. A limited 2024 pilot study suggested few differences in results between the paper and an online electronic format. The main aim of this master’s thesis is to extend the pilot study reliability investigation, plus expand it to different countries. Another objective is to investigate the impact of cultural/language factors on results from BIVSS translations into other languages. Related aims include exploring scoring variability within the 8-BIVSS symptom subcategories between different countries and for different causes of acquired brain injury.

Methods:

Healthcare providers from North America, Europe and Asia cooperated to help complete this international multicenter study. Subjects 18-70 years old with trauma caused ABI and non-trauma caused ABI were recruited. Prior to data gathering the BIVSS was translated into 8-different languages using the multistep “forward-backward translation” protocol method. The BIVSS questionnaire was converted to an electronic online format on the Qualtrics platform. Participants completed the BIVSS twice approximately a month apart, once on paper and once online, or vice-versa.

The BIVSS questionnaire is a 28-item Quality of Life survey with 8-subcategories: eyesight clarity, visual comfort, doubling, light sensitivity, drey eye, depth perception, peripheral vision and reading. Visual symptoms are rated on a Likert scale from 0 = never to 4 = always. The cutoff score is ≥ 32. Patients whose symptoms exceed this cutoff score have a high risk for significant visual problems related to mTBI.

Study protocol methods differed slightly between Asia, North America and Europe because of anonymization rules and data protection regulations. Responses to both questionnaires were summarized in an Excel table and analyzed using SPSS. The regression line and a Bland Altmann plot were created. The paired t-test (CI 95%, p < 0.05) was used to test the two formats for significant differences. The TOST test (with CI = 90%) was used to test the equivalence of the paper and online formats. This was performed twice, the first time with the equivalent mark of 0.2 SD, the second time with 0.5 SD. The other targets could only be represented with diagrams due to the limited number of subjects.

Results:

125-subjects from the USA, Canada, Spain, the Philippines and Luxembourg. Israel, China and Poland participated. Only 38-subjects (~ 30%) completed the required protocol and were included in the data analysis. Mean difference between electronic and paper formats was M = 1.76-points (+/-8.67SD). Bland Altmann scatter plot difference score was within the tolerance range [15.24; -18.76]. The paired t-test, p = 0.218 [CI 95%; p > 0.05] showed no significant differences between the two formats with an equivalence margin of 0.2 SD = 0 ± 1.74 points and the 90% CI [-4.1367; 0.6104]. In contrast, the TOST test failed (p-values [0.5081; 0.0088]). the TOST test showed equivalence between the paper and online formats with an equivalence margin of 0.5X SD = ± 4.34 points. The two p-values [0.0377; 0.0001] were within the 90% CI. Statistically meaningful statements could not be made about the other objectives due to the limited data set.

Conclusions:

In clinical practice, the electronic format of the BIVSS and the paper format can be treated as equivalent in most cases. When readministering the BIVSS with a patient, repeating the same format is recommended for follow-up. When the patient’s total BIVSS score is close to 32-points, sticking with the same format reduces the risk of potential misdiagnosis. Due to the small data set, no further extrapolative statements could be made. Further research is recommended to explore potential variables from language, non-traumatic caused ABI, and BIVSS symptom subcategories.

Keywords: Traumatic Brain Injury (TBI); Acquired Brain Injury (ABI); Brain Injury Vision Symptom Survey (BIVSS); International; Translation

Vorgelegt von: Xenia Bieche

Betreut von:

Frau Prof. Dr. Ana Nagl, Hochschule Aalen

Herr Karl Amon, Hochschule Aalen

31. August, 2025

Abstract

Ziele: Die Arbeit quantifiziert die Häufigkeit und Ausprägung skleraler Asymmetrie bei pathologischen Augen und überführt die Befunde in einen entscheidbaren Haptik-Entscheidungspfad (sphärisch → torisch → quadrantenspezifisch/segmentiert → vollflächig frei geformt).

Methodik: Retrospektives Design mit Vorstudie (Herstellerdaten 2015–2025 zur Referenzschwelle) und Hauptanalyse von n = 1 108 pathologischen Augen. Gemessen wurden ΔSag-Differenzen auf zwei Ringen (HWTW + 1 mm und HWTW + 4 mm) mittels Eye Surface Profiler (ESP) sowie Pentacam AXL Wave/CSP. Primärgröße pro Auge: Anteil gegenüberliegender Achsenpaare mit ΔSag > 225 µm. Analysen seiten- und gerätgetrennt; inferenzstatistisch Welch-t-Tests.

Ergebnisse: Relevante Asymmetrie liegt vor bei 64 % der Augen auf HWTW + 1 mm und ≈ 67 % auf HWTW + 4 mm. Die Median-Überschreitungsanteile der Achsenpaare betragen 0,778 (≈ 78 %) limbalnah und 0,861 (≈ 86 %) peripher; Unterschiede zwischen „Asymmetrie: Ja vs. Nein“ sind durchweg hochsignifikant mit großen bis sehr großen Effektstärken (z. B. d ≈ 2,19 für HWTW + 1 mm; d ≈ 1,48 für HWTW + 4 mm). Die Vorstudie verankert 225 µm als konservative Referenz (MLE-Mittel ≈ 226 µm).

Schlussfolgerung: Sklerale Asymmetrie ist häufig (≈ 2 von 3 Augen) und ausgeprägt; peripher überschreiten bei der Mehrzahl der Augen ≈ 86 % der Achsenpaare den 225-µm-Cut-off. Damit ist Rotationssymmetrie für pathologische Augen praktisch die Ausnahme. Der ringbasierte Entscheidungspfad liefert konkrete Schwellen und Prioritäten für die Haptik-Wahl:

1. Sphärisch nur bei klar sub-schwelligem ΔSag-Profil.
2. Torisch bei dominanter meridianspezifischer Differenz.
3. Quadrantenspezifisch/segmentiert bei ≥ 2 betroffenen Sektoren oder schrägen Mustern.
4. Vollflächig frei geformt bei mehrsektoralen/irregulären Profilen, Transplantatstufen oder lokalen Hindernissen (z. B. Notches).
   Dieser entscheidbare Pfad ersetzt „Trial-and-Error“ durch reproduzierbare Kriterien und ist klinisch wie versorgungstechnisch schlüssig (potenziell weniger Re-Fits, schnellere Stabilisierung, geringere Folgekosten).

Bezug zur Literatur (Auswahl): DeNaeyer et al. (2017, 2019); Ritzmann et al. (2018); Piñero et al. (2019); Barnett et al. – CLEAR Scleral (2021); Macedo-de-Araújo et al. (2022); Fadel & Consejo (2023).

Vorgelegt von: Natascha Lanz

Betreut von:

Frau Prof. Dr. Ana Nagl, Hochschule Aalen

Frau Katja Schiborr M.Sc., Hochschule Aalen

31. August, 2025

Abstract

Ziele: Diese Arbeit hat das Ziel, ein praxisnahes Manual für Optometristen zu entwickeln, welches einen strukturierten Überblick über das optometrische Sehfunktionstrainings (OSFT) in deutscher Sprache bietet. Das Manual orientiert sich an der integrativen Analyse nach Scheiman und Wick und dient als kompakter Leitfaden für die klinische Anwendung. Es werden darin ausgewählte Sehtrainingsübungen vorgestellt, die auf den Konzepten von Scheiman und Wick sowie der Pacific University College of Optometry basieren.
Optometrisches Sehfunktionstraining hat sich als wirksam bei der Behandlung von Akkommodationsstörungen und binokularen Sehstörungen ohne Strabismus erwiesen, mit Ausnahme der Divergenzinsuffizienz. Ziel ist es, eine deutschsprachige, leicht zugängliche Alternative zu den umfangreichen englischen Originalpublikationen bereitzustellen und so den klinischen Einsatz im deutschsprachigen Raum zu erleichtern.

Methodik: Im Rahmen dieser vorliegenden Arbeit wird ein theoretischer Überblick über das Optometrische Sehfunktionstraining (OSFT) erarbeitet. Dieses umfasst die Diagnostik und integrative Analyse basierend auf dem evidenzbasierten Modell von Scheiman und Wick. Darauf aufbauend werden gezielte Sehübungen für Störungen des binokularen Sehens, der Akkommodation und der Okulomotorik vorgestellt. Diese werden zusätzlich durch Inhalte der Pacific University College of Optometry ergänzt. Auch werden strukturierte Trainingspläne integriert. Parallel dazu entsteht ein Manual, das eine kompaktere Theorie enthält. Darin sind die Sehübungen detaillierter, mit Schritt-für-Schritt-Anleitungen, Illustrationen und Videos zur praktischen Anwendung festgehalten.

Ergebnisse: Entstanden ist eine umfangreiche Theorie in Form dieser Thesis zum Thema Optometrisches Sehfunktionstraining (OSFT). Dazu gibt es ein Manual, welches viele Bilder, Übersichten und Videos der Sehtrainingsübungen für die Praxis enthält.

Zusammenfassung: Im Rahmen dieser Arbeit wurde ein deutschsprachiges Manual zum optometrischen Sehfunktionstraining (OSFT) erstellt. Es bietet Optometristen eine strukturierte Übersicht evidenzbasierter Sehübungen zur Behandlung von Akkommodations- und binokularen Sehstörungen. Durch die Kombination aus theoretischem Hintergrund, illustrierten Anleitungen und Videomaterial soll die Umsetzung im klinischen Alltag erleichtert werden.

Keywords: Optometrisches Sehfunktionstrainings; Integrative Analyse; Binokulare Sehstörungen; Akkommodationsstörungen; Okulomotorische Dysfunktion; Sehtrainingsübungen

Vorgelegt von: Saša Ocerlič

Betreut von:

Prof. Dr. Anna Nagl, Aalen University

Dr. Matjaž Mihelčič, M.Sc., Aalen University

31. August, 2025

Purpose: 

Diabetes mellitus (DM) is a significant public health issue that is reaching epidemic levels worldwide. The number of people with diabetes is expected to rise drastically in the coming years. Uncontrolled or untreated diabetes often leads to serious complications, including cardiovascular, kidney, and neurological diseases. Long-term metabolic changes primarily damage small vessels, with the retinal vessels being most frequently affected in the form of diabetic retinopathy (DR). Effective and appropriate care in the early stages of DR can significantly reduce vision loss and improve patients’ quality of life. The purpose of this thesis is to support optometrists in the comprehensive care of patients with DR and to demonstrate how, as individuals and professionals, we can improve the treatment, monitoring, and overall management of this condition.

Methods: 

This thesis is based on a comprehensive review of current literature, including scientific journals available on Google Scholar, PubMed, books, and clinical guidelines.

Results: 

In my review I have tried to show how essential optometrists are in the multidisciplinary management of diabetic retinopathy. In addition to issuing spectacles and managing refractive errors, optometrists are important in the multi-disciplinary management of DR. An optometrist can enhance patient care and results significantly by performing thorough ocular evaluations with ancillary diagnostic tests like visual acuity (VA) testing, refraction, biomicroscopy, tonometry, and comprehensive retinal examinations. Moreover, providing appropriate follow-up care and educating patients along with timely and appropriate referrals further improve patient management and outcomes. Artificial intelligence can also serve as additional support for optometrists and ophthalmologists. One example is IDx-DR, the first medical device that uses artificial intelligence to detect diabetic retinopathy. The system is capable of identifying more than mild diabetic retinopathy, and it was approved by the FDA in 2018. AI holds significant promise for mass screening and unlocks new possibilities in detecting diabetic retinopathy, thereby improving the efficiency of disease management.

Conclusions: 

The purpose of this guide is to support optometrists in the comprehensive care of patients with diabetic retinopathy and to demonstrate how, as individuals and professionals, we can improve our approach to the treatment, monitoring, and overall management of this condition. This guide outlines the early signs of disease and reviews the classification and stage of disease severity in order to establish appropriate therapy. Since effective and appropriate care in the early stages of diabetic retinopathy can significantly reduce vision loss and improve patients’ quality of life, early recognition, patient education, and timely intervention are highly recommended.

Keywords: diabetes mellitus, diabetic retinopathy, optometry, ocular evaluation, management and referral, patient education

Author: Laura Ternik

Advisors:

Prof. Dr. Anna Nagl

Dr. Matjaž Mihelčič, M. Sc. Vision Science and Business (Optometry)

Delivery: August 31, 2025

Abstract

Purpose:

Multiple Sclerosis (MS) is a common autoimmune disease, that too often goes unnoticed in standard practice. The aim of this thesis is to provide optometrists with a structured framework on how to detect Multiple Sclerosis symptoms, and how to effectively identify MS-related ocular manifestations in their practice, as early recognition plays a crucial role in patients’ health outcomes. While there is existing literature on detecting Multiple Sclerosis through early visual symptoms, there remains no standardized framework to guide optometrists in their clinical approach.

Methods:

This will be a theoretical-based thesis, where I will use some examples of existing studies, to further prove some assumptions. Despite advancements in diagnostic tools, some early signs are still overlooked due to inconsistent examination protocols. An additional focus of this research, is to discuss specific biomarkers used in diagnosing MS with Optical Coherence Tomography (OCT), and how they correlate with the progression of the disease. Given their accessibility and expertise in ocular imaging, optometrists are in a position to detect these biomarkers early, able to contribute to timely diagnosis and referral, which can improve long-term outcomes for patients with MS.

Results:

The central research question for this thesis is: How can optometrists systematically detect early signs of MS to improve timely diagnosis and patient outcomes by doing the right measurements, asking the right questions and knowing when a patient needs referral to a specialist.

Conclusions:

Implementing a standardized approach - combining evidence-based clinical tests such as acuity, contrast sensitivity and color vision testing, including visual evoked potentials (VEP) and visual field (VF) testing, retinal nerve fiber layer (RNFL), ganglion cell inner plexiform layer (GCIPL) and macular volume (MV) analysis via OCT - can significantly improve the accuracy of early MS detection in optometric practice. However, the role of an optometrist is not only limited to identifying or diagnosing the disease; they can also aid in the treatment and visual rehabilitation, like prescribing prisms, vision therapy or other occupational strategies.

Keywords: Multiple Sclerosis; visual symptoms; optometrist; optic neuritis; Optical Coherence Tomography

Author: Bishal Hamal

Advisors:

Prof. Dr Anna Nagl, Aalen University

Dr Matjaž Mihelcic

Delivery: August 31, 2025

Abstract

Purpose:

To compare the Novel Nidek A-scan, Ultrasonic biometer, manual keratometer, and ultrasonic pachymeter in measurement of various ocular parameters.

Methods:

This study was done in Nepal eye hospital from February 2025- August 2025. A total of 326 patients presenting to the cataract clinic in Nepal eye hospital with clinically diagnosed age related cataract were enrolled in this study. Ultrasound biometry Echo Scan US-4000 (Nidek CO., LTD, Japan) and optical biometry AL-Scan (Nidek CO., LTD, Japan) were used to compare the axial length and IOL power in this study. Optical and ultrasonic pachymeter, optical biometer and manual keratometer were the devices opted for comparison.

Results:

The mean axial length in this study was 22.893 ± 0.850 mm in the optical biometry group and 22.723 ± 0.79 mm in ultrasound biometry group (range 21.38 - 24.44 mm and 20 -24.27 mm respectively). The mean axial length difference between the two groups was 0.169 ± 0.301 mm which is statistically significant (P<0.05). The mean IOL power in this study was 21.920 ± 1.736 D in the optical biometry group and 21.527 ± 1.758 D in ultrasound biometry group (range 17.50 - 26 D and 17-26 D respectively). The mean IOL power difference between the two groups was 0.39 ± 0.353 D (P<0.05) which is statistically significant. The mean AL in female subjects was 22.725 ± 0.044 and the AL in male subjects was 22.919 ± 0.048 and the difference is 0.19 mm which is statistically significant with (P value =0.00295). The mean IOL power in female subjects was 21.960 ± 0.094 D and the IOL power in male subjects was 21.407 ± 0.096 with p value < 0.001. The mean AL in Aryan subjects was 22.82 ± 0.70 mm and the AL in Mongolian subjects was 22.870 ± 0.043.

Conclusions:

Optical biometry has notable benefit over ultrasound biometry in measurement of axial length and determination of IOL power to be implanted for the cataract surgery. It is fast and convenient to use, has a high resolution and lower variability which may translate to more accurate measurements.

Keywords: Biometry, optical, ultrasonic, pachymetry, keratometry

Erstellerin: Dora Grle

Erstprüfer: Prof. Dr. Anna Nagl, Aalen University

Zweitprüfer: Damjan Žunić, Aalen University

Abgabe: 10. April 2025

Purpose:

The main purpose of this master thesis is to understand all available surgical treatments for presbyopia and match patients to the best option for them. These approaches offer different mechanisms for correcting presbyopia, each with advantages and limitations. However, objective ocular parameters are important in optimizing refractive outcomes in presbyopia surgery. A pre-operative assessment provides valuable insights that inform the selection of the most appropriate surgical approach for each patient. Personalized treatment plans and individual approaches are best suited to each patient's unique demands and preferences. Incorporating objective ocular parameters into surgical planning makes these possible. Ophthalmic surgeons and other healthcare professionals must have a comprehensive understanding of the technical aspects of these procedures and the importance of comprehensive patient care. Surgeons can determine each patient's optimal course of action through a thorough discussion and examination.

Methods:

In this work, secondary research will be carried out, encompassing pertinent sources such as controlled studies, cases extracted from public records, European and global journals, books, as well as private cases.

Conclusions:

Presbyopia is challenging for people who want to maintain near vision, which worsens with age. Surgical treatment of presbyopia offers a solution for better near vision without using glasses. When deciding which surgical treatment the patient is the best candidate for, we must consider objective ocular parameters that will help us optimize refractive outcomes. This thesis contributed valuable insights into the management of presbyopia, focusing on patient selection, surgical techniques, and postoperative care protocols. A personalized, patient-centered approach that combines technical precision, detailed analysis of all objective ocular parameters, and clear communication optimizes clinical outcomes and patient satisfaction in presbyopia surgery. A personalized, patient-centered approach combining technical precision, detailed analysis of all objective ocular parameters, and clear communication optimizes clinical outcomes and patient satisfaction in presbyopia surgery.

Keywords: Presbyopia, Monovision, Surgical treatment, Refractive surgery, Intraocular lens (IOL), Near vision

Author: Ivana Vrdoljak

First Examiner: Prof. Dr. Anna Nagl, Aalen University

Second Examiner: Damjan Žunić, M.Sc. Vision Science and Business (Optometry)

Delivery: October 31, 2025

Purpose of the Master Thesis:

This thesis explores the extent to which artificial intelligence (AI) can support, but not replace, human expertise in optometric care. It aims to evaluate the diagnostic capabilities and limitations of AI systems in detecting major ocular diseases—diabetic retinopathy, glaucoma, age-related macular degeneration, cataract, and keratoconus—and to examine ethical, regulatory, and professional implications of AI integration. The research further investigates how eye-care professionals perceive and use AI in clinical settings through a mixed-methods survey.

Methods:

A comprehensive literature review was conducted on peer-reviewed studies and meta-analyses concerning FDA- and CE-approved AI diagnostic systems. The analysis was supplemented by an original survey distributed to 81 optometrists and ophthalmologists worldwide. Quantitative data were analyzed in SPSS using descriptive statistics, Kruskal–Wallis tests, ordinal and multinomial logistic regressions, and correspondence analysis. Qualitative content analysis was performed on open-ended responses to identify common themes related to AI misdiagnosis, ethical concerns, and perceived professional impact.

Results:

AI systems such as IDx-DR, EyeArt, and Medios AI demonstrated high sensitivity (≥90%) and strong negative predictive value for detecting diabetic retinopathy, while AI in glaucoma, AMD, cataract, and keratoconus showed high potential but limited clinical generalizability. Among survey respondents, 45.7% reported occasional AI use, 11.1% regular use. 76.5% viewed AI as an assistive tool. Regular users rated AI’s diagnostic accuracy significantly higher than non-users (p = 0.010). Profession and years of experience influenced adoption of AI, with ophthalmologists and more experienced clinicians showing greater usage. Qualitative findings confirmed concerns about false positives, automation bias, and ethical accountability, while emphasizing that empathy, communication, and contextual interpretation remain uniquely human competencies.

Conclusions:

AI has become an indispensable adjunct in modern optometric diagnostics, capable of enhancing efficiency, consistency, and early disease detection. However, it cannot substitute for the holistic, ethical, and interpretative dimensions of human clinical judgment. The European AI Act and related medical-device regulations reinforce this principle through mandatory human oversight. The findings support a complementary model in which optometrists and ophthalmologists collaborate with AI to deliver safer, fairer, and more comprehensive eye care.

Keywords: Artificial intelligence, Optometry, Ophthalmology, Diagnostic accuracy, Diabetic retinopathy, Glaucoma, Ethical oversight, Human expertise, EU AI Act, Automation bias