{"id":{"repo_id":"houston","oai_identifier":"oai:uh-ir.tdl.org:10657/4812"},"canonical_url":"https://search.dev.ndltd.org/etd/houston/oai:uh-ir.tdl.org:10657/4812","repository":{"repo_id":"houston","name":"University of Houston","base_url":"https://uh-ir.tdl.org/server/oai/request"},"display":{"title":"Lamina Cribrosa and Optic Nerve Head Geometry as a Function of Myopia in Older Normal Eyes","abstract":"Purpose: Increased age and levels of myopia are potential risk factors for the development of glaucoma. However, their impact on optic nerve head (ONH) structure in normal eyes has not been fully described. We examined whether differences exist in ONH and lamina cribrosa structure with myopia in older normal eyes. Methods: Spectral domain optical coherence tomography (SDOCT) scans centered on the ONH were acquired in one eye of 15 older normal subjects (mean = 58.1 ± 7.4 years) with high myopia (spherical equivalent [SE] ≤ -6.00 D) and 16 older normal subjects (mean = 57.5 ± 6.8 years) with emmetropia to moderate myopia (SE = plano to -6.00 D). Retinal nerve fiber layer thickness (RNFLT) was quantified from 12° circular scans. ONH features were marked in each of 48 radial B-scans (20° field) using a semi-automated MATLAB program to calculate Bruch’s Membrane Opening (BMO) area and circumference, mean anterior lamina cribrosa surface depth (ALCSD), mean minimum rim width (MRW) and mean scaled MRW. Results: Refractive errors and axial lengths (ALs) in highly myopic eyes (mean SE = -7.18 ± 1.17 D; mean AL = 26.41 ± 0.76 mm) were statistically different from emmetropic/low myopic eyes (mean SE = -1.59 ± 1.63 D; mean AL = 24.92 ± 1.06 mm) (P<.01). While RNFLT was thinner in older eyes with high myopia (85.5 ± 7.7 μm) compared to those with emmetropia/low myopia (99.2 ± 5.0 μm; P<.01), no significant differences were measured in other ONH parameters between groups. Mean MRW was significantly thinner in highly myopic eyes with larger BMO areas (P=.04) and tended to be thinner in eyes with more posteriorly-located ALCS’s (P=.09). Conversely, no significant relationships were found between MRW and ALCSD (P=.60) or BMO area (P=.54) in older eyes with emmetropia/low myopia. Conclusion: The tendency for mean MRW to be thinner in highly myopic eyes with more posteriorly-located ALCS’s and larger BMO areas could indicate that axons are pulled toward the BMO in eyes with a deeper lamina. This anatomical configuration may increase the biomechanical susceptibility for glaucomatous axonal damage in older, highly myopic eyes.","abstract_html":"Purpose: Increased age and levels of myopia are potential risk factors for the development of glaucoma. However, their impact on optic nerve head (ONH) structure in normal eyes has not been fully described. We examined whether differences exist in ONH and lamina cribrosa structure with myopia in older normal eyes. Methods: Spectral domain optical coherence tomography (SDOCT) scans centered on the ONH were acquired in one eye of 15 older normal subjects (mean = 58.1 ± 7.4 years) with high myopia (spherical equivalent [SE] ≤ -6.00 D) and 16 older normal subjects (mean = 57.5 ± 6.8 years) with emmetropia to moderate myopia (SE = plano to -6.00 D). Retinal nerve fiber layer thickness (RNFLT) was quantified from 12° circular scans. ONH features were marked in each of 48 radial B-scans (20° field) using a semi-automated MATLAB program to calculate Bruch’s Membrane Opening (BMO) area and circumference, mean anterior lamina cribrosa surface depth (ALCSD), mean minimum rim width (MRW) and mean scaled MRW. Results: Refractive errors and axial lengths (ALs) in highly myopic eyes (mean SE = -7.18 ± 1.17 D; mean AL = 26.41 ± 0.76 mm) were statistically different from emmetropic/low myopic eyes (mean SE = -1.59 ± 1.63 D; mean AL = 24.92 ± 1.06 mm) (P<.01). While RNFLT was thinner in older eyes with high myopia (85.5 ± 7.7 μm) compared to those with emmetropia/low myopia (99.2 ± 5.0 μm; P<.01), no significant differences were measured in other ONH parameters between groups. Mean MRW was significantly thinner in highly myopic eyes with larger BMO areas (P=.04) and tended to be thinner in eyes with more posteriorly-located ALCS’s (P=.09). Conversely, no significant relationships were found between MRW and ALCSD (P=.60) or BMO area (P=.54) in older eyes with emmetropia/low myopia. Conclusion: The tendency for mean MRW to be thinner in highly myopic eyes with more posteriorly-located ALCS’s and larger BMO areas could indicate that axons are pulled toward the BMO in eyes with a deeper lamina. This anatomical configuration may increase the biomechanical susceptibility for glaucomatous axonal damage in older, highly myopic eyes.","abstract_has_math":false,"creators":["Nourani-Dargiri, Sara"],"institution":"University of Houston","degree_name":"Master of Science","degree_level":"Masters","degree_discipline":"Physiological Optics and Vision Science","degree_department":null,"school":null,"contributors":[],"advisors":["Porter, Jason"],"committee_chairs":[],"committee_members":["Harwerth, Ronald S.","Marrelli, Danica J.","Ostrin, Lisa A."],"year":2017,"date_issued":"2017-08","date_published":"2017-08","updated_at":"2026-07-24T02:32:34Z","subjects":["Myopia","Glaucoma","Glaucoma imaging","High myopia","Lamina cribrosa","Minimum rim width"],"languages":["eng"],"rights":["The author of this work is the copyright owner. UH Libraries and the Texas Digital Library have their permission to store and provide access to this work. Further transmission, reproduction, or presentation of this work is prohibited except with permission of the author(s)."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/10657/4812","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Porter, Jason"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Harwerth, Ronald S.","Marrelli, Danica J.","Ostrin, Lisa A."]},{"key":"dc:creator","label":"Author","values":["Nourani-Dargiri, Sara"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2019-09-18T02:17:05Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2019-09-18T02:17:05Z"]},{"key":"dc:date.issued","label":"Date","values":["2017-08"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Physiological Optics and Vision Science"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Houston"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Myopia","Glaucoma","Glaucoma imaging","High myopia","Lamina cribrosa","Minimum rim width"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["The author of this work is the copyright owner. UH Libraries and the Texas Digital Library have their permission to store and provide access to this work. Further transmission, reproduction, or presentation of this work is prohibited except with permission of the author(s)."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10657/4812"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Purpose: Increased age and levels of myopia are potential risk factors for the development of glaucoma. However, their impact on optic nerve head (ONH) structure in normal eyes has not been fully described. We examined whether differences exist in ONH and lamina cribrosa structure with myopia in older normal eyes. Methods: Spectral domain optical coherence tomography (SDOCT) scans centered on the ONH were acquired in one eye of 15 older normal subjects (mean = 58.1 ± 7.4 years) with high myopia (spherical equivalent [SE] ≤ -6.00 D) and 16 older normal subjects (mean = 57.5 ± 6.8 years) with emmetropia to moderate myopia (SE = plano to -6.00 D). Retinal nerve fiber layer thickness (RNFLT) was quantified from 12° circular scans. ONH features were marked in each of 48 radial B-scans (20° field) using a semi-automated MATLAB program to calculate Bruch’s Membrane Opening (BMO) area and circumference, mean anterior lamina cribrosa surface depth (ALCSD), mean minimum rim width (MRW) and mean scaled MRW. Results: Refractive errors and axial lengths (ALs) in highly myopic eyes (mean SE = -7.18 ± 1.17 D; mean AL = 26.41 ± 0.76 mm) were statistically different from emmetropic/low myopic eyes (mean SE = -1.59 ± 1.63 D; mean AL = 24.92 ± 1.06 mm) (P<.01). While RNFLT was thinner in older eyes with high myopia (85.5 ± 7.7 μm) compared to those with emmetropia/low myopia (99.2 ± 5.0 μm; P<.01), no significant differences were measured in other ONH parameters between groups. Mean MRW was significantly thinner in highly myopic eyes with larger BMO areas (P=.04) and tended to be thinner in eyes with more posteriorly-located ALCS’s (P=.09). Conversely, no significant relationships were found between MRW and ALCSD (P=.60) or BMO area (P=.54) in older eyes with emmetropia/low myopia. Conclusion: The tendency for mean MRW to be thinner in highly myopic eyes with more posteriorly-located ALCS’s and larger BMO areas could indicate that axons are pulled toward the BMO in eyes with a deeper lamina. This anatomical configuration may increase the biomechanical susceptibility for glaucomatous axonal damage in older, highly myopic eyes."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Lamina Cribrosa and Optic Nerve Head Geometry as a Function of Myopia in Older Normal Eyes"]}]}],"canonical_facts":{"dc:contributor.advisor":["Porter, Jason"],"dc:contributor.committeemember":["Harwerth, Ronald S.","Marrelli, Danica J.","Ostrin, Lisa A."],"dc:creator":["Nourani-Dargiri, Sara"],"dc:date.accessioned":["2019-09-18T02:17:05Z"],"dc:date.available":["2019-09-18T02:17:05Z"],"dc:date.issued":["2017-08"],"dc:description.abstract":["Purpose: Increased age and levels of myopia are potential risk factors for the development of glaucoma. However, their impact on optic nerve head (ONH) structure in normal eyes has not been fully described. We examined whether differences exist in ONH and lamina cribrosa structure with myopia in older normal eyes. Methods: Spectral domain optical coherence tomography (SDOCT) scans centered on the ONH were acquired in one eye of 15 older normal subjects (mean = 58.1 ± 7.4 years) with high myopia (spherical equivalent [SE] ≤ -6.00 D) and 16 older normal subjects (mean = 57.5 ± 6.8 years) with emmetropia to moderate myopia (SE = plano to -6.00 D). Retinal nerve fiber layer thickness (RNFLT) was quantified from 12° circular scans. ONH features were marked in each of 48 radial B-scans (20° field) using a semi-automated MATLAB program to calculate Bruch’s Membrane Opening (BMO) area and circumference, mean anterior lamina cribrosa surface depth (ALCSD), mean minimum rim width (MRW) and mean scaled MRW. Results: Refractive errors and axial lengths (ALs) in highly myopic eyes (mean SE = -7.18 ± 1.17 D; mean AL = 26.41 ± 0.76 mm) were statistically different from emmetropic/low myopic eyes (mean SE = -1.59 ± 1.63 D; mean AL = 24.92 ± 1.06 mm) (P<.01). While RNFLT was thinner in older eyes with high myopia (85.5 ± 7.7 μm) compared to those with emmetropia/low myopia (99.2 ± 5.0 μm; P<.01), no significant differences were measured in other ONH parameters between groups. Mean MRW was significantly thinner in highly myopic eyes with larger BMO areas (P=.04) and tended to be thinner in eyes with more posteriorly-located ALCS’s (P=.09). Conversely, no significant relationships were found between MRW and ALCSD (P=.60) or BMO area (P=.54) in older eyes with emmetropia/low myopia. Conclusion: The tendency for mean MRW to be thinner in highly myopic eyes with more posteriorly-located ALCS’s and larger BMO areas could indicate that axons are pulled toward the BMO in eyes with a deeper lamina. This anatomical configuration may increase the biomechanical susceptibility for glaucomatous axonal damage in older, highly myopic eyes."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["https://hdl.handle.net/10657/4812"],"dc:language.iso":["eng"],"dc:rights":["The author of this work is the copyright owner. UH Libraries and the Texas Digital Library have their permission to store and provide access to this work. Further transmission, reproduction, or presentation of this work is prohibited except with permission of the author(s)."],"dc:subject":["Myopia","Glaucoma","Glaucoma imaging","High myopia","Lamina cribrosa","Minimum rim width"],"dc:title":["Lamina Cribrosa and Optic Nerve Head Geometry as a Function of Myopia in Older Normal Eyes"],"thesis:degree_discipline":["Physiological Optics and Vision Science"],"thesis:degree_level":["Masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["University of Houston"]},"updated_at":"2026-07-24T02:32:34Z"}