Hemoderivative therapy has long been explored to manage ocular blast trauma and persistent epithelial defects — related methods, including serum- and plasma-based eye drops have also shown usefulness, but treatments such as autologous serum (AS) eye drops for dry eye disease (DED) are expensive and require laboratories to process blood. A randomized controlled trial published in Clinical Ophthalmology explores how finger-prick autologous blood (FAB) can improve severe DED.
The investigation took place at 2 centers in the UK affiliated with Moorfields Eye Hospital, and included 60 patients who were cluster-randomized into 1 of 2 cohorts; FAB treatment plus conventional DED therapy, or conventional therapy alone — the control group. Case participants watched a 5-minute finger stick and self-administration video, and practiced with an ophthalmic nurse. After hand-washing and 70% isopropyl wipe, a safety lancet was used to produce a drop of blood to be rolled into the lower conjunctival fornix. A masked clinician assessed individuals at baseline, and weeks 4 and 8.
After 8 weeks, the ocular surface disease index (OSDI) scores of the FAB cohort improved; -17.68 (-37.67 to -2.96) points, compared with those for the control set at -7.04 (P =.02). After multivariable adjustment, results remained superior for case participants, but with less significance (P =.05). At 12 weeks — 4 weeks after completing FAB — patients treated with autologous blood continued their lower OSDI scores, although these scores were comparable with control individuals (P >.05). No safety issues or adverse events occurred.
Investigators measured objective signs including fluorescence tear film break-up time (TBUT), Schirmer’s test, and fluorescein Oxford corneal surface grading (OCSG). Participants treated with FAB had more improvement than control individuals in TBUT and OCSG, but these data did not reach the level of statistical significance (P >.05).
Previous research demonstrates that blood-derived therapies offer trophic nutrition for epithelial cells. Whole blood directly applied to the eye is helpful for ocular surface conditions because it contains both trophic peptides and substances found in tears; fibronectin and growth factors. Whole blood has no supplementary anticoagulants or other additives, and is available right away.
“A key concern from clinicians is the acceptability to patients of having to prick their fingers several times a day, however, the FAB technique is chiefly suited to those patients who cannot access AS either because of the aforementioned lack of funding or access to appropriate licensed laboratory services to process blood such as in developing nations,” according to the investigators. “Furthermore, interviews with patients were conducted to ascertain the acceptability of the technique with all saying they would recommend this to family and friends if they had severe DED.” Therapy entailed 4 daily sticks to 1 finger per eye, which can be difficult for older adults.
This trial was a feasibility study, which limits it due to a relatively small population and no sample size power estimate. Notably, post-hoc interviews found that all participants would suggest FAB to friends and family with severe dry eye. However, the placebo effect is not ruled out because individuals self-administered the blood drop and could not be masked. Two systematic study reviews demonstrated similar results to the present work, specifically that AS eye drops bettered OSDI scores, but did not meaningfully change results of Schirmer’s test or TBUT. The trial adds unique data on FAB for severe dry eye disease.
Hassan A, Balal S, Cook E, et al. Finger-prick autologous blood (fab) eye drops for dry eye disease: single masked multi-centre randomised controlled trial. Clin Ophthalmol. Published online on December 2, 2022. doi:10.2147/OPTH.S384586