id_840. L-TYROSINE AS A DOPAMINE PRECURSOR: SYSTEMIC SUPPLEMENTATION SUPPORTS RETINAL FUNCTION IN A MOUSE MODEL OF FORM-DEPRIVATION MYOPIA
Bartosz Machna1,2,3, Klaudia Mroz1,2, Monika Katan1,2, Anna Gasiorek1,2, Anna Pacwa1,2,6,9, Maciej Oseka3, Mikołaj Górka5,7, Joanna Lewin-Kowalik1,2,6, Adrian Smedowski1,2,4,6,8
1 Medical University of Silesia, Laboratory for Translational Research in Ophthalmology, Department of Ophthalmology, Faculty of Medical Sciences in Katowice, Katowice, Poland
2 Medical University of Silesia, Department of Ophthalmology, Faculty of Medical Sciences in Katowice, Katowice, Poland
3 Oftalabs Sp. z o.o., Wałbrzych, Poland
4 Medical University of Silesia, Department of Ophthalmology, Professor K. Gibinski University Clinical Center, Faculty of Medical Sciences in Katowice, Katowice, Poland
5 Medical University of Silesia, Department of Biochemistry and Medical Genetics, Faculty of Health Sciences in Katowice, Katowice, Poland
6 Glaucotech Co, Katowice, Poland
7 Medical University of Silesia, Department of Experimental Medicine, Medical University of Silesia in Katowice, Katowice, Poland
8 Medical University of Silesia, Department of Paedriatric Ophthalmology, Faculty of Medical Sciences in Katowice, Katowice, Poland
9 Medical University of Silesia, Department of Clinical Genetics and Rare Diseases, Faculty of Medical Sciences in Katowice, Katowice, Poland
INTRODUCTION: High myopia is a growing global public health concern due to its rising prevalence and association with severe sight-threatening complications, including myopic maculopathy, retinal detachment, and glaucoma. Preclinical studies show reduced retinal dopamine signaling in form-deprivation myopia (FDM). As L-tyrosine is the precursor for dopamine synthesis, systemic supplementation is hypothesized to modulate ocular growth and retinal function in myopia.
AIM(S): This study aims to examine the effects of L-tyrosine supplementation on ocular morphometry and retinal function in a mouse model of form-deprivation myopia.
METHOD(S): Four-week-old C57BL/6 mice were used in a form-deprivation myopia model induced through unilateral tarsorrhaphy (eyelid suturing). Animals were randomly divided into two groups: an experimental group with a subcutaneous implantation of a slow-release L-tyrosine delivery system, and a control group subjected to a sham procedure. After the treatment period, axial length and corneal diameter at limbus were measured on high-resolution images using ImageJ software. Retinal function was evaluated by full-field electroretinography (ERG), including scotopic, mixed, photopic, and oscillatory potential responses.
RESULTS: Form-deprivation induced by tarsorrhaphy resulted in significantly greater ocular growth in eyes subjected to tarsorrhaphy (FDM). This growth was more pronounced in the sham-treated group compared to eyes of mice receiving systemic L-tyrosine. Electroretinographic recordings showed that tarsorrhaphy-treated eyes exhibited submaximal responses compared to the contralateral healthy eye. L-tyrosine application led to improved retinal function, particularly in rod responses, mixed responses, photopic negative responses, and oscillatory potentials.
CONCLUSIONS: L-tyrosine supplementation shows potential role in regulating emmetropization and preserving retinal bioelectrical responses. These results support further exploration of therapeutic potential in myopia management and prevention.
FINANCIAL SUPPORT: Ministry of Science and Higher Education (Poland), "Doktorat wdrożeniowy" programme, grant no. DWD/6/0407/2022