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

ABSTRACT

Purpose: The proportion of axial length (AL) occupied by vitreous chamber depth (VCD), or VCDAL, consistently correlates to ocular biometry in the general population. Relation of VCDAL to ocular biometry in high myopia is not known. The purpose of this study is to evaluate the relation of VCD and VCDAL to ocular biometry of highly myopic eyes. Methods: This was a cross?sectional retrospective study of records of 214 myopic eyes (<?1 D SE, aged 20–40 years) attending the refractive surgery services. High axial myopia was defined as AL >26.5 mm. Eyes with posterior staphyloma and myopic maculopathy were excluded. Records were assessed for measurements of AL, central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), white to white diameter (WTW), and vitreous chamber depth (VCD). Groups were formed based on increasing AL, while the sum of CCT, ACD, and LT was recorded as anterior segment depth (AS). The main outcome measure was the correlation of VCD and VCDAL to ocular biometry. A comparison was also performed based on of degree of axial myopia. Results: Mean age of the patients was 27.0 ± 5.2 years. VCD showed a very strong correlation with AL (R = 0.98, P < 0.001) but did not correlate to any anterior parameter. VCDAL showed moderate negative relation with AS (R = ?0.43, P < 0.001) and ACD (R = ?0.3, P < 0.001), while it had a weakly negative relation with LT (R = ?0.18, P = 0.006). VCDAL showed strong negative relation (R > ~0.7) with AS in all individual groups of AL. Among anterior parameters, WTW showed the most consistent relation with ocular biometry. Conclusion: VCDAL is a better correlate of ocular biometry in high myopia as compared to VCD. However, the correlation is weaker than that noted by previous studies done on the general population. Longitudinal studies of VCDAL in the younger age group is recommended