Correlation of axial length and myopic macular degeneration to levels of molecular factors in the aqueous

Abstract

To elucidate the molecular processes associated with the development of myopic macular degeneration (MMD), we measured the intraocular concentrations of molecular factors in emmetropic and myopic eyes. This is a retrospective clinic-based case-control study that included eyes undergoing routine cataract surgery whereby aqueous humour samples were obtained. We measured the concentrations of pigment epithelium derived factor(PEDF), matrix metalloproteinase 2(MMP-2), tissue inhibitor of metalloproteinase(TIMP-2), vascular endothelial growth factor isoform A(VEGF-A), interleukin 8(IL-8), interleukin 6(IL-6), C-reactive protein(CRP), angiopoietin 2(Ang2), and amphiregulin. 38 eyes (axial length (AL): 22.4–32.4 mm), including 12 highly myopic (HM) eyes (AL ≥ 26.5 mm) without MMD and 12 HM eyes with MMD but without neovascularization were included. Eyes with MMD were found to have significantly lower VEGF-A levels (p = 0.007) and higher MMP-2 levels (p = 0.02) than control eyes after adjusting for age and gender. MMP-2 levels correlated positively (r = 0.58, p = 0.002), while VEGF-A levels correlated negatively with longer axial length (r = −0.75, p < 0.001). Both the concentrations of VEGF-A (P = 0.25) and MMP-2 (P = 0.69) were not significantly associated with MMD after adjusting for AL. These findings suggest that the predominant mechanism underlying the development of non-neovascular MMD may be axial elongation, driven in part by MMP-2 related mechanisms.

IMI Pathologic Myopia

“… 137 Alterations in the cytokine levels have also been described in eyes with pathologic myopia and may contribute to the pathogenesis of myopic MNV. 138 In eyes with myopic MNV, an increased VEGF level has been found in the aqueous humor compared with eyes undergoing cataract surgery. 139 There have also been a suggestion that genetic or hereditary factors may play a role in the development of myopic MNV.…”

Correlation of vitreous chamber depth with ocular biometry in high axial myopia

“…This was done because posterior staphyloma causes posterior bulging of the eyeball and patients with myopic maculopathy can have reduced visual acuity (worse than 20/40); thus, these could have potentially been inferred in biometric evaluation. [ 25 ] An optical non-contact biometer (Lenstar LS 900, Haag-Streit, Switzerland) was used by a single ophthalmic technician for assessing the biometry of all eyes. Measurements that were recorded included AL (from the corneal epithelium to the internal limiting membrane of the retina), central corneal thickness (CCT; from the corneal epithelium to the endothelium), average Keratometry, anterior chamber depth (ACD; from corneal endothelium to the anterior capsule of the crystalline lens), lens thickness (LT; from the anterior capsule of the lens to the posterior capsule of the lens), and white to white diameter (WTW; the horizontal distance between nasal limbal border to the temporal limbal border).…”

AREG is involved in scleral remodeling in form‐deprivation myopia via the ERK1/2‐MMP‐2 pathway

“…For example, Sharma et al’s 19 study showed a higher tear concentration of dopamine than in plasma samples in adults, indicating that tear dopamine assessments can be used to monitor dopamine levels. Cheung's 24 study showed the AREG concentrations in 61% of the aqueous samples were lower than the limit of detection (2.122 pg/ml). In the present study, the average AREG concentration in tear fluids was 110.60 ± 4.31 pg/ml (Table S4), and none of the measurements were below the limit of detection, suggesting a higher concentration of AREG in tears than in aqueous samples.…”