DISCORDANCE BETWEEN ANTERIOR SEGMENT ANATOMY AND AXIAL LENGTH IN CATARACT SURGERY CANDIDATES IN FRANCE.

INTRODUCTION
To study ocular biometric data and their association with age and sex in a population of cataract surgery candidates. To assess the proportion of inhomogeneous eyes and the ratio anterior segment (AS) to axial length (AL). Multicentric cross-sectional analysis between April 2008 and May 2021 in public and private ophthalmic institutions in Montpellier, France. Individuals ≥ 40 years old who underwent ocular biometry before cataract surgery were included.


METHODS
Right phakic eyes were included. Ocular biometrics were measured by using the Lenstar LS900 device. We defined AS as anterior chamber depth (ACD) plus lens thickness (LT) and calculated the ratio of AS to AL. We defined inhomogeneous eyes as those with deep AS (≥ 4th quartile) and short AL (≤ 1st quartile) (AS+) or with short AS and high AL (AL+).


RESULTS
We included 11,650 individuals (11,650 eyes) (mean [SD] age 71.64 [10.50] years; 54.51% women). Older age was associated with shorter AL (p<0.01), shallower ACD (p < 0.01), thinner central corneal thickness (p< 0.01) and larger LT (p<0.001). Women had shorter AL, shallower ACD, and thinner central corneal thickness than men (p<0.001). In total, 778 (6.68%) eyes were inhomogeneous (3.22% AS+ and 3.46% AL+), for a mean (SD) AS/AL ratio of 0.36 (0.01) and 0.28 (0.01), respectively, as compared with 0.32 (0.02) for homogeneous eyes (p<0.001).


CONCLUSION
The AS/AL ratio could be useful to screen inhomogeneous eyes before cataract surgery and justify the use of new generation formulas in these eyes to avoid the risk of refractive error.