A meta-analysis of alterations in the retina and choroid in high myopia assessed by optical coherence tomography angiography

Peripapillary retinal thickness and its risk factors in dry-type high myopia

INTRODUCTION

To evaluate the alterations in the peripapillary retinal thickness and its risk factors in dry-type high myopia (HM).

METHODS

One hundred and twenty eyes in 69 HM subjects were collected from March 2023 to July 2023 with the age, refractive diopter, axial length (AL), posterior scleral staphyloma, type of myopic maculopathy, and peripapillary retinal thickness. Divided into three groups according to the international photo-graphic classification system: Category 0 (C0) with no myopic retinal degenerative lesions, Category 1 (C1) with tessellated fundus, and Category 2 (C2) with diffuse chorioretinal atrophy. Peripapillary retinal thickness was assessed using swept-source optical coherence tomography (SS-OCT) B-scans. All data were analyzed with the SPSS software version 23.0 by one-way ANOVA test among three groups. Linear regression and pearson correlation analysis were used to determine the relationships among measurements.

RESULTS

The retinal thickness of the peripapillary was measured from the superior, nasal, inferior, and temporal directions around the optic disc. The superior, nasal, and inferior peripapillary retinal thickness in the C2 group decreased significantly in all three groups. The retinal thicknesses decreased significantly with the increase of AL in the superior, nasal, and inferior. The retinal thicknesses increased significantly with the increase of refractive diopter, except for the temporal sector. The retinal thickness decreased significantly with the increase of age in dry-type HM. There was no significant difference between peripapillary retinal thickness and the wide macular staphyloma.

CONCLUSIONS

Individuals in the C2 group had a thinner peripapillary retinal thickness than other groups, except for the temporal sector. The retinal thicknesses of the peripapillary decreased significantly with the increase of AL and increased significantly with the increase of refractive diopter, except for the temporal sector. With the increase of age, the retinal thickness of the peripapillary decreased significantly. Ophthalmologists and HM patients should pay attention to changes in the thickness of the peripapillary retina and the growth of age.

A cohort study of 19 patients with gyrate atrophy of the choroid and retina (GACR)

PURPOSE

Gyrate atrophy of the choroid and retina (GACR) is an autosomal recessive inherited metabolic disorder (IMD) characterised by progressive retinal degeneration, leading to severe visual impairment. The rapid developments in ophthalmic genetic therapies warrant knowledge on clinical phenotype of eligible diseases such as GACR to define future therapeutic parameters in clinical trials.

METHODS

Retrospective chart analysis was performed in nineteen patients. Data were analysed using IBM SPSS Statistics version 28.0.1.1.

RESULTS

Nineteen patients were included with a mean age of 32.6 years (range 8-58). Mean age at onset of ophthalmic symptoms was 7.9 years (range 3-16). Median logMAR of visual acuity at inclusion was 0.26 (range -0.18-3.00). Mean age at cataract surgery was 28.8 years (n = 11 patients). Mean spherical equivalent of the refractive error was -8.96 (range -20.87 to -2.25). Cystoid maculopathy was present in 68% of patients, with a loss of integrity of the foveal ellipsoid zone (EZ) in 24/38 eyes. Of the 14 patients treated with dietary protein restriction, the four patients who started the diet before age 10 showed most benefit.

CONCLUSION

This study demonstrates the severe ophthalmic disease course associated with GACR, as well as possible benefit of early dietary treatment. In addition to visual loss, patients experience severe myopia, early-onset cataract, and CME. There is a loss of foveal EZ integrity at a young age, emphasising the need for early diagnosis enabling current and future therapeutic interventions.

VEGFA may be a potential marker of myopic choroidal thickness and vascular density changes

To evaluate the changes of choroidal thickness (CT) and blood flow related to myopia, and its effects of vascular endothelial growth factor (VEGFA) on choroidal vessels in myopia. Subjects were included and divided into emmetropia (EM), non-high myopia (Non-HM) and high myopia (HM) groups. we measured choroidal thickness (CT), choriocapillaris vessel density (VD), and VEGFA content in tears in humans (137 subjects for CT, VD and 84 for tear) and detected the role of VEGFA in the choroid in form-deprivation myopia (FDM) in guinea pigs. Twenty-four guinea pigs were divided into control and FDM groups, and the expression changes of choroidal vessels and VEGFA were observed and compared using immunohistochemistry and Western blotting. Twenty-one guinea pigs were divided into control, FDM + Vehicle and FDM + Conbercept groups. The changes of diopter, axis length and choroidal vessels after intravitreal injection of Conbercept were observed. There were significant differences in CT and VD among the three groups (p < 0.05). VEGFA levels in tears were significantly lower in the myopic groups, with a decreasing trend from EM to Non-HM to HM. The choroidal vascular area fraction of FDM decreased compared to the control group. FDM guinea pigs exhibited reduced choroidal vasculature and significant downregulation of VEGFA expression. Following intravitreal injection of conbercept, the FDM + Conbercept group showed greater myopia, longer axial length, and lower choroidal vascular area fraction compared to the control group. VEGFA may participate in the regulation of choroidal blood vessels and blood flow in the progression of myopia. The reduction in VEGFA may accelerates the progression of myopia.

Microvasculature and microstructure alteration in dry-type high myopia

BACKGROUND

To investigate the alterations in the retinal vasculature and microstructure in dry-type high myopia.

METHODS

One hundred and eighty-nine dry-type high myopia eyes were classified into three groups. Group 1 consisted of 86 eyes with no myopic retinal degenerative lesion (C0). Group 2 consisted of 71 eyes with tessellated fundus (C1). Group 3 consisted of 32 eyes with diffuse chorioretinal atrophy (C2). Retinal vascular density and retinal thickness were measured with optical coherence tomography angiography. The scanning area was a 3 × 3 mm2 ring with the fovea of the macular. All data were analyzed with the SPSS 23.0 by one-way ANOVA test among comparison groups. Pearson's correlation analysis was used to determine the relations among measurements. Univariate linear regression showed a correlation between the vascular densities and retinal thicknesses.

RESULTS

The microvessel density significantly decreased and significant thinning of the superior and temporal macular thickness in the C2 group. The vascular densities of macular decreased significantly with the increase of axial length (AL) and refractive diopter in the C2 group. The retinal thicknesses of the macular fovea increased significantly with the increase of vascular densities in the C0 group and C1 group.

CONCLUSIONS

The impairment of retinal microstructure is more likely related to reduced oxygen and nutrients due to microvessel density decreases.

Choroidal Vascular Density Quantification in High Myopia with or without Choroidal Neovascularization Using Optical Coherence Tomography Angiography

Purpose

The aim of this study was to analyze choroidal vascular density alteration in high myopia with or without choroidal neovascularization by using optical coherence tomography angiography (OCTA).

Methods

This was a cross-sectional, observational study that included 60 high-myopia eyes. All the participants had comprehensive ophthalmic assessments with visual acuity, intraocular pressure, slit lamp-assisted biomicroscopy, color fundus photography, axial length, optometry, and OCTA. Age, sex, and comorbidities were collected from their medical charts. Univariate and multiple analyses were made to compare the age, spherical equivalent, choroidal vascular density, gender, and choroidal thickness between normal and patients with choroidal neovascularization.

Results

60 eyes with high myopia were included in our study, including 30 eyes with choroidal neovascularization and 30 eyes without choroidal neovascularization or other fundus pathology. The mean age of high myopic patients was older in the choroidal neovascularization group than in the normal group (48.43 ± 19.06 years vs. 28.83 ± 9.92 years, p < 0.01). The mean choroidal thickness of high myopic patients was thinner in the neovascularization group than in the normal group (68.81 ± 48.81 μm vs. 137.80 ± 66.33 μm, p < 0.01). The mean choroidal vascular density in the normal group was greater than in the choroidal neovascularization group (82.43 ± 8.73 vs. 67.54 ± 12.56, p < 0.01). There was no significant difference in spherical equivalent between the choroidal neovascularization group and the normal group (-10.56 ± 2.97D vs. -11.93 ± 3.38D, p = 0.11). Multivariate analysis showed that after adjusting for covariates, less choroidal vascular density and older age were independent factors associated with choroidal neovascularization in the high myopic eye.

Conclusion

Decreased choroidal vascular density and older age played an important role in the development of choroidal neovascularization in high myopic eyes. OCTA may help us to identify the highly myopic patients that need to intervene.

Assessment of macular structures and vascular characteristics in highly myopic anisometropia using swept-source optical coherence tomography angiography

Purpose: This study aimed to explore the macular structures and vascular characteristics of more myopic (MM) and contralateral eyes with highly myopic anisometropia.

Methods: Comprehensive ophthalmic examinations were performed for 33 patients with highly myopic anisometropia. Macular structures (total retinal layer [TRL], ganglion cell and inner plexiform layer [GCIPL], inner nuclear layer [INL], outer retinal layer [ORL], nerve fiber layer [NFL], choroidal layer [CHL]) and vascular characteristics (superficial vascular complex density [SVD], deep vascular complex density [DVD], choriocapillaris perfusion area [CCPA]) were assessed using swept-source optical coherence tomography (SS-OCT) and OCT angiography (OCTA). Macular structures and vascular characteristics of each subregion were compared to those of the Early Treatment of Diabetic Retinopathy Study (ETDRS).

Results: With highly myopic anisometropia, the thicknesses of the TRL, GCIPL, INL, and ORL in MM eyes were smaller than those in contralateral eyes in at least one quadrant of the perifoveal and parafoveal circles (all p &lt; 0.05), with no changes in the foveal and temporal quadrants of perifoveal regions (all p &gt; 0.05). A thicker NFL (p = 0.018) was found in MM eyes than in contralateral eyes in the superior perifoveal quadrant. The CHL (all p &lt; 0.05) in MM eyes was thinner in all regions than in the contralateral eyes according to the ETDRS. There were no statistical differences in the SVD, DVD, and CCPA of MM and contralateral eyes (all p &gt; 0.05).

Conclusion: All retinal layers, except the NFL, tended to be thinner in all subregions, except the temporal perifoveal and foveal quadrants in MM eyes, and choroidal thickness was thinned in all areas.