IPoster: Impact of Form Deprivation-Induced Myopia on the Ciliary Body

Purpose: Human refractive error is negatively correlated with ciliary body thickness. The purpose of this study was to determine if form deprivation-induced myopia concomitantly impacts guinea pig ciliary body development.

Methods: Changes in ciliary body gene expression were assessed following monocular form deprivation of Strain 13 guinea pigs (n = 3) for ~1 week. Eyes were then enucleated, placed in RNAlater®, RNA was isolated from the ciliary bodies, sequenced (Illumina HiSeq 4000 platform), and treated and control eye gene expression differences were determined with bioinformatics and Ingenuity Pathways Analysis (IPA). Morphologically induced ciliary muscle changes were investigated by monocularly form depriving Strain 13 (n=4) and Cincinnati (n=4) guinea pigs for ~1 week and histologically analyzing between eye differences.

Results: Bioinformatics determined that collagen alpha-1 (XII) chain (-2.30 fold) and thrombospondin-1 (-2.30 fold) were significantly (P < 0.10) downregulated in the treated eyes compared to the control eyes. IPA found an additional 470 genes that met a 1.5 fold differential expression threshold, genes that were primarily associated with (number of genes) cell morphology (169), cell movement (143), cellular development (161), cellular growth and proliferation (225), and cellular assembly and organization (152). Morphological analysis indicated that mean ciliary muscle growth was inhibited in treated compared to control eyes (cross-sectional areas: 0.045 ± 0.01 mm2 vs. 0.052 ± 0.02 mm2; cell sizes: 244.02 ± 22.83 μm2/cell vs. 250.23 ± 23.77 μm2/cell).

Conclusion(s): Both approaches failed to find evidence of ciliary body hypertrophy in response to monocular form deprivation after 1 week, a stimulus that may actually inhibit growth. These data are in contrast to human findings, which may indicate that form deprivation-induced myopia is different than human juvenile myopia.

Andrew D. Pucker, OD, PhD, FAAO

Dr. Andrew D. Pucker earned his OD and MS in Vision Science from The Ohio State University College of Optometry in 2011. His MS work focused on contact lenses lipid deposition. He also developed new methods for analyzing the tear film lipid layer. Dr. Pucker is presently a Senior Research Associate and pursuing a PhD in Vision Science at The Ohio State University, where he also currently serves as the Principal Investigator of a five-year, NIH Award titled “Mechanotransduction in the Ciliary Muscle” (NEI: K08EY023264). The aim of his grant is to characterize molecular and biomechanical changes related to mechanical stretch in the ciliary muscle during eye growth. Dr. Pucker also continued his interest in tear film, dry eye, and contact lenses by serving as a co-chair of the Contact Lens Assessment in Symptomatic Subjects (CLASS) Study group and by implementing other independent projects related to these topics. Dr. Pucker is a regular contributing author to the American Optometric Association’s Contact Lens and Cornea Section Newsletter. He is a Fellow of the American Academy of Optometry (2011), and he is a past winner of the Carl Zeiss Vision Fellowship (2010), William C. Ezell Fellowship (2011 & 2012), and The Ohio State University’s Outstanding Professional Student Award (2011).