Autologous serum eyedrops for dry eyes and epithelial defects: clinical and in vitro toxicity studies. Poon AC, Geerling G, Dart JKG, Fraenkel GE, Daniels JT. Br J Ophthalmol 2001;85:1188–1197

Abstract

Autologous serum drops have been reported to be beneficial in keratoconjunctivitis sicca (KCS) and persistent epithelial defects (PED). The authors conducted a clinical pilot study to examine these potential uses. In vitro toxicity testing on corneal epithelial cell cultures was performed to compare the effect of serum drops with unpreserved hypromellose (hydroxypropylmethylcellulose 0.3%). Patients with KCS and PED unresponsive to conventional treatment were recruited. Patients were examined before treatment, at 1 and 2 weeks after initiation, and then twice weekly until treatment ceased. Clinical examination included Schirmer test without anesthesia, rose bengal staining, and fluorescein staining. Epithelial defects were measured with the slit beam. In the laboratory, cultured human corneal epithelial cells were exposed to serum drops and hypromellose and their viability evaluated with fluorescent viability staining (Calcein AM ethidium homodimer) and an ATP assay. Autologous serum was used in 15 eyes of 13 patients with PED and 11 eyes of 9 patients with KCS. In two patients serum drops were started after penetrating keratoplasty (PK). The PKs were performed for perforations secondary to PEDs. Of the 15 eyes with PED, 9 healed at a mean of 29 days and 6 failed. The mean duration of PED before the use of serum drops was 48.2 days. Of the 11 eyes with KCS, 6 had improved subjective scores and fluorescein scores, and 5 had improved rose bengal scores after the use of serum drops. For the two patients who used serum eyedrops post-PK, there was a stable and intact epithelium at 1 week. Cessation of serum drops during the postoperative period led to deterioration in the subjective and objective scores in both patients. One developed a PED that responded to reinstitution of serum drops. The morphology and ATP levels of cultured epithelial cells exposed to serum were better maintained than those exposed to hypromellose. The authors conclude that autologous serum drops are useful for PED and KCS. This effect may be related to a number of active factors in serum, including growth factors, fibronectin, vitamin A, and antiproteases. In vitro toxicity testing demonstrated that serum drops have reduced toxicity compared with unpreserved hypromellose.—Thomas J. Liesegang