Reduced aqueous humour ascorbic-acid concentration in women with smaller anterior chamber depth

Sakae Ito,Takehisa Machida,Koichiro Mukai,Toshimi Sairenchi,Tadashi Senoo,Gen Kobashi,Akihito Ishigami,Yuka Takino,Yoshitaka Kondo

doi:10.1038/s41598-018-36899-8

Abstract

Short anterior chamber depth (ACD) is considered a risk factor of endothelial-cell loss after phacoemulsification. However, whether it is an independent risk factor or not remains controversial. We investigated the relationship between ascorbic acid (AA) concentrations in the aqueous humour (AqH) and ACD. We analysed 165 AqH samples of 97 patients (42 men and 55 women) who underwent small incision cataract surgery. AqH and plasma AA concentrations were measured using a high-performance liquid chromatography - electrochemical detection method. Patient characteristics were compared between and within the sexes. As a result, age and ACD were significantly correlated with AqH AA concentrations (r = −0.206, P = 0.045; r = 0.339, P < 0.001) only in women. Moreover, plasma AA concentrations were significantly correlated with AqH AA concentrations (r = 0.420, P < 0.001; r = 0.316, P = 0.002) both in men and women. After adjusting for confounding factors (age and plasma AA concentrations), ACD was significantly and positively correlated with AqH AA concentrations (partial.r = 0.275, P = 0.009) only in women. In conclusion, AqH AA concentrations were reduced in women with smaller ACD. This may suggest that women with short ACD could be more susceptible to oxidative damage.

Highlights

Ascorbic acid (AA) concentration in the human aqueous humour (AqH) is more than 20-fold higher than in the plasma[1,2,3]
AqH ascorbic acid (AA) concentrations were significantly lower in men (1535 ± 326 μmol/L vs. 1733 ± 355 μmol/L, respectively; P < 0.001), whereas there was no significant difference in plasma AA concentrations between the sexes (48.4 ± 18.1 μmol/L vs. 52.7 ± 15.9 μmol/L, respectively; P = 0.105)
The present study showed that AqH AA concentrations were significantly and positively correlated with anterior chamber depth (ACD) in women after adjusting for confounding factors

Summary

Introduction

Ascorbic acid (AA) concentration in the human aqueous humour (AqH) is more than 20-fold higher than in the plasma[1,2,3]. Ultrasonic phacoemulsification for cataract surgery results in the formation of free radical species and causes injury in corneal endothelial cells[13,14]. Walkow et al.[15] and Storr-Paulsen et al.[16] reported that eyes with shorter axial length (AL) had significantly increased risk for endothelial-cell loss. Some researchers have considered that short ACD might be a risk factor for corneal endothelial-cell damage[15,22,23]. Our knowledge, no report has considered the association between ACD and AA concentrations in the AqH. We hypothesised that short ACD would be more susceptible to oxidative damage and that it would be associated with decrease in AqH AA concentration. In this study, we examined the relationship between ACD and AqH AA concentrations in patients with cataract and examined whether the association between these two factors is affected by patient characteristics

Methods

Results

Conclusion