Chinnery Holly R, Naranjo Golborne Cecilia, Downie Laura E
Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Australia.
Ophthalmic Physiol Opt. 2017 Jul;37(4):473-481. doi: 10.1111/opo.12365. Epub 2017 Mar 12.
To investigate whether oral, long-chain omega-3 (ω-3) essential fatty acid (EFA) supplementation, for 3 months, induces changes to the central corneal sub-basal nerve plexus in dry eye disease and whether nerve alterations correlate with clinical findings.
This prospective, comparative study involved the final 12 participants enrolled in a randomised, double-masked, placebo-controlled clinical trial of 60 participants with moderate dry eye disease. Participants received either placebo (olive oil 1500 mg/day; n = 4) or ω-3 EFA supplements (~1000 mg/day eicosapentaenoic acid + ~500 mg/day docosahexaenoic acid; n = 8) for 90 days. The main outcome measure was the mean change in central corneal sub-basal plexus nerve parameters between days one and 90, quantified using in vivo confocal microscopy. Secondary outcomes included mean change in tear osmolarity, corneal dendritic cell density and basal epithelial cell density.
Compared with baseline, the reduction in OSDI score and tear osmolarity at day 90 were greater in the ω-3 EFA group than the placebo group (OSDI: ω-3 EFA, mean ± SEM: -15.6 ± 2.8 vs placebo: -2.8 ± 4.1 units, t = 2.6, p = 0.04; tearosmolarity: ω-3 EFA: -22.63 ± 5.7 vs placebo: -8 ± 2.7 mOsmol/L, t = 2.3, p = 0.04). At day 90, corneal total nerve branch density (CTBD: 91.1 ± 8.6 vs 45.1 ± 13.4 branches/mm , F = 14, p = 0.004) and corneal nerve branch density on the main fibre (CNBD: 63.4 ± 6.5 vs 27.9 ± 11.5 branches/mm , F = 6, p = 0.03) were higher in the ω-3 EFA group compared with placebo. Relative to day 1, CNBD (branches/mm ) increased at day 90 in the ω-3 EFA group (+20.0 ± 9.2, t = 3.2 p = 0.01) compared with placebo (-10.8 ± 3.2). Similar changes were evident for corneal nerve fibre length (CNFL, mm/mm ), which increased from baseline at day 90 in the omega-3 EFA group (+2.9 ± 1.6, t = 3.4 p = 0.01) compared with placebo (-2.7 ± 0.5). There was a negative correlation between CTBD and tear osmolarity (r = -0.70, p = 0.01). No significant changes were observed for basal epithelial cell or corneal dendritic cell density.
These pilot study findings suggest that ω-3 EFA supplementation imparts neuroprotective effects in the corneal sub-basal plexus that correlate with the extent of tear osmolarity normalisation.
研究口服长链ω-3（ω-3）必需脂肪酸（EFA）3个月是否会引起干眼病患者角膜中央基底膜下神经丛的变化，以及神经改变是否与临床发现相关。
这项前瞻性比较研究纳入了60例中度干眼病患者的随机、双盲、安慰剂对照临床试验的最后12名参与者。参与者接受安慰剂（橄榄油1500毫克/天；n = 4）或ω-3 EFA补充剂（约1000毫克/天二十碳五烯酸 + 约500毫克/天二十二碳六烯酸；n = 8），为期90天。主要观察指标是第1天和第90天之间角膜中央基底膜下神经丛神经参数的平均变化，使用体内共聚焦显微镜进行量化。次要观察指标包括泪液渗透压、角膜树突状细胞密度和基底上皮细胞密度的平均变化。
与基线相比，ω-3 EFA组在第90天时OSDI评分和泪液渗透压的降低幅度大于安慰剂组（OSDI：ω-3 EFA，平均值±标准误：-15.6±2.8对安慰剂：-2.8±4.1单位，t = 2.6，p = 0.04；泪液渗透压：ω-3 EFA：-22.63±5.7对安慰剂：-8±2.7毫摩尔/升，t = 2.3，p = 0.04）。在第90天时，ω-3 EFA组的角膜总神经分支密度（CTBD：91.1±8.6对45.1±13.4分支/毫米，F = 14，p = 0.004）和主要纤维上的角膜神经分支密度（CNBD：63.4±6.5对27.9±11.5分支/毫米，F = 6，p = 0.03）高于安慰剂组。与第1天相比，ω-3 EFA组在第90天时CNBD（分支/毫米）增加（+20.0±9.2，t = 3.2，p = 0.01），而安慰剂组则降低（-10.8±3.2）。角膜神经纤维长度（CNFL，毫米/毫米）也有类似变化，ω-3 EFA组在第90天时相对于基线增加（+2.9±1.6，t = 3.4，p = 0.01），而安慰剂组则降低（-2.7±0.5）。CTBD与泪液渗透压之间存在负相关（r = -0.70，p = 0.01）。基底上皮细胞或角膜树突状细胞密度未观察到显著变化。
这些初步研究结果表明，补充ω-3 EFA对角膜基底膜下神经丛具有神经保护作用，且与泪液渗透压正常化程度相关。
