Oral Hyaluronic Acid Supplementation for the Treatment of Dry Eye Disease: A Pilot Study

Purpose . To evaluate the clinical efficacy of oral hyaluronic acid (HA) in patients with dry eye disease (DED). Study Design . Prospective randomized controlled trial. Methods . This trial enrolled 54 subjects and they were randomized into the study or control group. The inclusion criteria were as follows: (1) &gt;18 years of age; (2) distance best-corrected visual acuity ≥ 20/40 Snellen equivalent in each eye; (3) IOP ≤ 21 mmHg in both eyes; (4) ocular surface disease index (OSDI) score of ≥18 and &lt;65; (5) &lt;10 seconds of tear break up time (TBUT); (6) &gt;5 corneal spots of corneal fluorescein staining (CFS); and (7) ≤ 10 mm/5 min of the Schirmer test. All subjects were treated with a topical HA, and the study group was supplemented with oral HA. OSDI, TBUT, CFS, and the Schirmer test were evaluated for ocular surface parameters. Results . 24 patients were assigned in the study group. Significant improvement of OSDI, TBUT, and CFS was observed at 1 month and 3 months after oral HA administration in the study group. At baseline and follow-up at 1 and 3 months, OSDI scores were 61.8 ± 16.2, 47.3 ± 11.6, and 42.3 ± 9.1, respectively (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:mi>P</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.001</mml:mn></mml:mrow></mml:math>). TBUT was improved after treatment for 1 month and 3 months (4.2 ± 1.1; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mrow><mml:mi>P</mml:mi><mml:mo>=</mml:mo><mml:mn>0.005</mml:mn></mml:mrow></mml:math> and 4.7 ± 1.1; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mrow><mml:mi>P</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.012</mml:mn></mml:mrow></mml:math>). There were also statistically significant improvements in the CSF (1.8 ± 1.0, 0.8 ± 0.7; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mrow><mml:mi>P</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.001</mml:mn></mml:mrow></mml:math>) at baseline compared with those at 1 month. Conclusions . A combined supplement of both oral and topical HA more efficiently improves corneal epithelial wound healing and related symptoms than topical HA alone, in DED.