Eficacia del suero autólogo versus vehículo en la enfermedad de ojo seco inducida por cirugía refractiva cornealestudio prospectivo, randomizado y doble-enmascarado

Abstract

PURPOSE. To determine the efficacy of topical autologous serum (SAT) compared to its vehicle, balanced saline solution (BSS) in the intensity of the potential symptoms and signs related to the dry eye disease (DED) that patients can suffer in the postoperative period after corneal refractive surgery (CRC), specifically after advanced surface ablation (ASA). METHODS. A phase IV, randomized, double-masked and vehicle-controlled clinical trial was designed and approved by the corresponding Ethics Committee. All patients had the same protocolized treatment (antibiotics, antinflamatories, and artificial tears). The trial treatment was randomized so that one eye received SAT and the contralateral eye from the same patient, BSS from the time after CRC and for 6 months. Symptoms were evaluated using the ocular surface disease questionnaire (OSDI). The following signs were also evaluated: visual acuity (VA), tear osmolarity, tear break-up time (TBUT), cornea and conjunctiva vital staining, mechanical and thermal (heat and cold) corneal esthesiometry, and tear production using the Schirmer test. The effect of time course and treatment was statistically analyzed, comparing pre-CRC values with those at month 1, 3, and 6 post-CRC. A better outcome for the SAT group in tear osmolarity or corneal sensitivity was defined as the primary evaluation endpoints. RESULTS. 36 eyes of 18 patients (11 women, 7 men; mean age 34.6 years) were included. VA improved significantly, being a line significantly higher at one month in the BSS group and equalizing afterwards. Tear osmolarity was abnormally high preCRC and was decreasing post-CRC, doing so significantly earlier in the SAT group, where it was already normal and significantly lower than that of BSS after the 1st month, while in the BSS group did not decrease to normal values until the 3rd month. OSDI values were abnormally high pre-CRC, progressively improving without differences between groups. Conjunctival hyperemia, TBUT, ocular surface vital staining, and thermal (hot and cold) esthesiometry were always within normal limits and without influence by time or treatment. Mechanical corneal sensitivity and Schirmer test, always within normal limits, increased significantly at 6 months in both groups equally. CONCLUSIONS. No patient developed DED in the postoperative period and, in fact, all the parameters were within a normal range, except those previously altered, OSDI and osmolarity, which normalized in the postoperative period. One of the two success criteria was met, as tear osmolarity was more advantageous with SAT than with BSS, with no differences in the other parameters. Taking into account that these patients were already receiving anti-inflammatory treatment, the difference in the behavior of tear osmolarity guarantees that autologous serum is prescribed in the postoperative period of ASA-type CRC