Abstract
Purpose : Myopia prevalence is increasing globally and the choroid is considered an important biomarker in myopia development. As myopia and choroidal thinning are associated with increased glaucoma risk, understanding the role of the choroid in myopia and glaucoma is imperative. This abstract investigates the effect of transiently elevated intraocular pressure (IOP) on axial length (AL), subfoveal choroidal thickness (SFCT) and central retinal thickness (CRT) in emmetropes (EM), low myopes (LM) and high myopes (HM).
Methods : This study involved 29 young (22.8±1.2 years) adults, including 10 EM (-0.50DS< SER<+0.50DS), 10 LM (-6.00D<SER≤-0.50 DS) and 9 HM (SER≤-6.00 DS). Participants were fitted with modified swimming goggles for 5 minutes to transiently increase IOP. Non-contact tonometry, optical biometry, and optical coherence tomography were used to measure IOP, AL, CRT and SFCT, respectively. Measurements were taken at four timepoints: before, during, immediately and 3 minutes after goggles removal. RM-ANOVA with Bonferroni adjustment was used to assess the effect of transiently increased IOP and to elucidate any differences between refractive groups in response to the IOP change.
Results : There was no significant difference in baseline IOP and CRT across refractive groups (p>0.05). However, HM exhibited longer AL and thinner SFCT compared to EM and LM (p<0.001). IOP increased by 1.65±0.40 mmHg (p=0.002) from baseline, accompanied by axial elongation of 14±4 µm (p=0.012) and SFCT thinning of 12.5±2.7 µm (p=0.01; Fig.1). SFCT thinning accounted for 85% of the change in AL. IOP, AL and SFCT returned to baseline immediately following goggles removal. Refraction did not significantly contribute to the level of change. CRT did not change with increased IOP (p>0.05).
Conclusions : Transiently increased IOP caused temporary axial elongation and SFCT thinning, with no significant differences between refractive groups. Further studies are required to assess the impact of choroidal thinning induced by transiently increased IOP on ocular perfusion and its relationship with myopia.
Methods : This study involved 29 young (22.8±1.2 years) adults, including 10 EM (-0.50DS< SER<+0.50DS), 10 LM (-6.00D<SER≤-0.50 DS) and 9 HM (SER≤-6.00 DS). Participants were fitted with modified swimming goggles for 5 minutes to transiently increase IOP. Non-contact tonometry, optical biometry, and optical coherence tomography were used to measure IOP, AL, CRT and SFCT, respectively. Measurements were taken at four timepoints: before, during, immediately and 3 minutes after goggles removal. RM-ANOVA with Bonferroni adjustment was used to assess the effect of transiently increased IOP and to elucidate any differences between refractive groups in response to the IOP change.
Results : There was no significant difference in baseline IOP and CRT across refractive groups (p>0.05). However, HM exhibited longer AL and thinner SFCT compared to EM and LM (p<0.001). IOP increased by 1.65±0.40 mmHg (p=0.002) from baseline, accompanied by axial elongation of 14±4 µm (p=0.012) and SFCT thinning of 12.5±2.7 µm (p=0.01; Fig.1). SFCT thinning accounted for 85% of the change in AL. IOP, AL and SFCT returned to baseline immediately following goggles removal. Refraction did not significantly contribute to the level of change. CRT did not change with increased IOP (p>0.05).
Conclusions : Transiently increased IOP caused temporary axial elongation and SFCT thinning, with no significant differences between refractive groups. Further studies are required to assess the impact of choroidal thinning induced by transiently increased IOP on ocular perfusion and its relationship with myopia.
| Original language | English |
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| Journal | Investigative Ophthalmology & Visual Science (IOVS) |
| Publication status | Published - Jun 2024 |
| Event | Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO) - Seattle, United States Duration: 5 May 2024 → 9 May 2024 https://www.arvo.org/annual-meeting/meeting-info/past-annual-meetings/ |