Linda McLoon, PhD

Dr. McLoon received her PhD from the Department of Anatomy at the University of Illinois Medical Center, followed by postdoctoral studies with Dr. Ray Lund at the University of Washington and Medical University of South Carolina. She is a tenured Professor in the Department of Ophthalmology and Visual Neurosciences. She studies pharmacologic approaches to the treatment of eye movement disorders in children, specifically strabismus and nystagmus. She is focused on the cell biology and muscle stem cell populations within the muscles that move the eyes in the orbit, the extraocular muscles, to understand their sparing in diseases such as Duchenne muscular dystrophy and what goes awry in eye movement disorders. Recently she has added an interest in sex differences in retinal function and how this relates to neuropsychiatric disease

• Member of the Editorial Boards of Scientific Reports, Investigative Ophthalmology and Visual Science, and the Journal of the American Association for Pediatric Ophthalmology and Strabismus (JAPPOS)
• Scientific Review Committee, Fight for Sight, 2011-present
• Honorary Member (one of 6 so honored), American Association for Pediatric Ophthalmology and Strabismus, 2012-present
• Elected to Board of Trustees, Association for Research in Vision and Ophthalmology, 2011-2016
• Gold Fellow, Association for Research in Vision and Ophthalmology, 2009-present
• Lew Wasserman Mid-Career Merit Award, Research to Prevent Blindness, 2005-06
• American Society of Ophthalmic Plastic and Reconstructive Surgery Research Award for the most outstanding research published in the journal in 2002.

Research Summary/Interests

My laboratory focuses on understanding the potential mechanisms for two types of eye movement disorders: strabismus and nystagmus. Untreated these result in decreased visual acuity. Both involve the ocular motor system and the specialized skeletal muscles that move the eye, the extraocular muscles (EOM). We focus on the ability of retrogradely transported neurotrophic factors to alter the function and structure of the ocular motor system with the goal of developing a permanent therapeutic approach for these movement disorders. We have used RNAseq data to identify potential new therapeutic targets for development of treatments.

A second focus is the study of the muscle stem cell populations in the EOM that cause their differential sparing in degenerative disorders such as muscular dystrophy and amyotrophic lateral sclerosis. We have identified a specific stem cell, expressing Pitx2, which we have implicated in this differential sparing. Further work will focus on using these stem cells to prevent limb muscle degeneration in these currently untreatable diseases.

Finally, we have started a new project looking at the electroretinogram (ERG) in various mouse models of disease. Our recent studies show a significant difference in ERG characteristics in a mouse model of schizophrenia compared to controls, suggesting a specific method by which differences in the brain can be measured in the retina.

Research interests:

• Development of pharmacologic treatments for strabismus and infantile nystagmus syndrome
• Extraocular muscle cell biology
• Sparing of the extraocular muscles in muscular dystrophies
• Molecular control of extraocular muscle properties and how these are affected in strabismus and nystagmus
• Sex differences in the electroretinogram

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PEER REVIEWED PUBLICATIONS

1.Johnson LL, Kueppers RB, Shen EY, Rudell JC, McLoon LK. Development of nystagmus in the absence of MYOD expression in the extraocular muscles. PMID: 34617961. Invest. Ophthalmol. Vis. Sci. 2021 Oct 4;62(13):3.

2.Torres Jimenez N, Miller RF, McLoon LK. Effects of D-serine treatment on outer retinal function. PMC8511128. Exp. Eye Res. 2021;211:108732.

3.Rudell JC, McLoon LK. Effects of fibroblast growth factor 2 on extraocular muscle structure and function. PMC8300058. Invest. Ophthalmol. Vis. Sci. 2021;62:34.

4.Rudell JC, Fleuriet J, Mustari MJ, McLoon LK. Childhood onset strabismus: a neurotrophic factor hypothesis. Invited review. PMC8102408. J. Binocul. Vis. Ocul. Motil. 2021;Apr 19:1-6.

5.Hampe CS, Wesley J, Lund TC, Orchard PJ, Polgreen LE, Eisengart JB, McLoon LK, Cureoglu S, Schachern P, McIvor RS. Mucopolysaccharidosis type I: Current treatments, limitations, and prospects for improvement. PMC7911293. Biomolecules. 2021;Jan 29;11(2):189.

6.Fleuriet J, Willoughby CL, Kueppers RB, Mustari MJ, McLoon LK. Eye alignment changes caused by sustained GDNF treatment of an extraocular muscle in infant non-human primates. PMC7368047. Sci. Rep. 2020;10:11927.

7.Rudell JC, Stager DR, Felius J, McLoon LK. Morphological differences in inferior oblique muscles from subjects with over-elevation in adduction. PMC7415317. Invest. Ophthalmol. Vis. Sci. 2020;61(6):33.

8.Torres Jimenez N, Lines J, Kueppers RB, Rankila A, Wei H, Kofuji P, Coyle J, Miller RF, McLoon LK. Electroretinographic abnormalities and sex differences detected with mesopic adaptation in a mouse model of schizophrenia: A and B wave analysis. PMC7326504. Invest. Ophthalmol. Vis. Sci. 2020 Feb 7;61(2):16.

9.Moghimi P*, Torres Jimenez N*, McLoon LK, Netoff TI, Lee MS, MacDonald III A, Miller RF. Electroretinographic evidence of retinal ganglion cell-dependent function in schizophrenia. PMC7442157. Schizophr. Res. 2020;219:34-46. *: co-first authors

10.Olson RM, Mokhtarzadeh A, McLoon LK, Harrison AR. Effects of repeated eyelid injections with botulinum toxin A on innervation of treated muscles in patients with blepharospasm. PMC6397080. Curr. Eye Res. 2019;44:257-263.

11.Fleuriet J, McLoon LK. Visualizing neuronal adaptation over time after treatment of strabismus. PMC6188464. Invest. Ophthalmol. Vis. Sci. 2018;59:5022-5024.