FAB a viable therapy for recalcitrant dry eye syndrome
Fingerprick autologous blood (FAB) appears to be effective and safe in the treatment of severe dry eye syndrome (DES), eliminating the need for blood donation and specialist processing, as reported in a pilot study.
“The results … indicate that FAB is a viable therapy for recalcitrant DES unresponsive to conventional therapy, and that continued application of blood is required to maintain improvements in both symptoms and signs seen during therapy,” the authors said.
In the study, a total of 16 patients (29 eyes) with severe DES were instructed to apply a drop of blood pricked from the finger four times daily for 8 weeks. After treatment, improvements were seen in mean Oxford corneal staining grade (3.31‒2.07; p<0.0001), tear break-up time (5.00‒7.80 s; p<0.05), visual acuity (0.08‒0.01 LogMAR equivalent; p<0.05), and ocular comfort index score (56.03‒39.72; p<0.0001). [Eye 2017;31:1655–1663]
At 4 weeks after treatment completion, however, mean staining grade and ocular comfort index score worsened from 2.07 to 2.86 (p<0.0001) and from 39.72 to 44.67 (p<0.05), respectively.
In terms of safety, FAB was well tolerated. There were no complications reported in any patient during the trial, and FAB had no effect on intraocular pressure.
The authors pointed out that after study completion, all patients continued FAB therapy of their own accord, the longest for 28 months, without any reported complications. This should provide some assurance to clinicians who express concern regarding the acceptability to patients of having to prick their fingers several times a day to provide relief for their eyes.
“FAB should [thus] be considered as an alternative low-cost, readily accessible treatment for severe DES,” they said, while admitting that it is not presently clear how the erythrocytes and leucocytes of FAB affect the ocular surface.
Although the study did not highlight any complications with FAB therapy, the authors noted that adverse events could potentially occur. These events pertain to the risks of ocular infection through transfer of skin pathogens via repeated close contact between finger and eye, transmission of blood-borne pathogens to the anterior eye, and tissue damage at the fingertips due to repeated fingerpricks.
“A randomized controlled trial to compare FAB therapy with conventional topical therapy and autologous serum is necessary to validate our initial findings,” as well as to address several questions regarding the biological mechanism of FAB therapy and its potential complications, the authors said.