MAR 2014

EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.

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Page 104 of 210

E W CORNEA 102 March 2014 Inconsistent research made definitive conclusions difficult I n the quest to treat patients with severe dry eye, some oph- thalmologists use autologous serum drops. Just how effective are the drops in treating dry eye? A review article published last year in the Cochrane Database of Systematic Reviews took a closer look at this topic. 1 Ultimately, they con- cluded that more research needs to be done. An extensive review The study investigators, led by Qing Pan, MD, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, and Department of Ophthalmology, Zhejiang Provincial People's Hospi- tal, Hangzhou, China, noted in the review that autologous serum eye drops can provide lubrication and important biochemical components that mimic natural tears for dry eye patients. They also noted that serum eye drops are becoming a more pop- ular second-line therapy to treat dry eye. For these reasons, they wanted to evaluate the efficacy and safety of serum eye drops compared with arti- ficial tears as analyzed in previous randomized controlled trials. Two of the review authors screened titles and abstracts and ex- tracted relevant data. They found a total of 402 titles and abstracts but whittled that down to 360 after eliminating duplicate reports. They then identified 30 reports from 29 studies that might be relevant for the review. Despite the initially large num- ber of potential titles and abstracts, they were only able to find four studies relevant to their exacting re- search criteria, specifically random- ized clinical trials—three full-text reports from three trials and one full-text report and conference abstract that presented results from another trial. A total of 72 participants with dry eye due to various etiologies (e.g., Sjogren's syndrome, non- Sjogren's syndrome, and post-LASIK) were included in the four trials. The number of participants per trial ranged from 12 to 27, and the age range was 30 to 60 years old in three trials and 50 to 75 years old in a fourth trial. Participants in all four trials were instructed to use 20% autolo- gous serum four, five, or six times a day. Participants in the four trials re- ceived similar instructions regarding serum drop storage. Each trial used a different method to evaluate participants' symptom improvement, and each trial had a different follow-up time. The findings The four trials analyzed by Dr. Pan and co-investigators had varying re- sults. One trial with 12 participants showed no improvement in partici- pant-reported symptoms when comparing 20% serum drops and artificial tears at one month. In two of the trials with a total of 32 partici- pants, the serum drops showed some improvement in participant- reported symptoms compared with a rtificial tears after two weeks of use. A fourth trial had positive results and a mean difference in tear break- up time of two seconds after two weeks. The use of serum drops did not show any improvements related to aqueous tear production based on Schirmer test results, tear quality b ased on fluorescein staining or rose bengal staining, and ocular surface condition based on impression cy- tology compared with artificial tears. However, as the investigators pointed out, these measurements were not done consistently among all four trials. Some trials used these measurements and some did not. N one of the trials evaluated tear osmolarity, corneal topography, flu- orescein clearance, or conjunctival biopsy. The studies also did not report quality of life or economic analyses. Three trials did not provide any information on adverse events. One trial reported two participants using serum drops with signs of conjunc- tivitis with negative culture, but the cases resolved with treatment. The investigators concluded that the trials included in their re- view showed inconsistency in any benefits that serum drops might pro- vide. "Twenty percent [serum drops] might provide some benefit in im- proving participant-reported symp- toms in the short term (two weeks), but improvement was not observed through longer periods of follow- up," the investigators wrote. The investigators concluded that larger-scale randomized con- trolled trials are needed to make any definitive conclusions about the effects of autologous serum eye drops for dry eye. They went on to specify how such a trial should be designed, pointing out the need for stratification by age and dry eye severity, a comparison of serum drops to artificial tears or other treatments, and the evaluation of additional concentrations of serum drops. "Any future studies should utilize standardized and validated scoring systems of dry eye clinical severity and symptom question- naires," they wrote. "Objective bio- markers … such as tear osmolarity, tear cytokines, and HLA-DR expres- sion by ocular surface cells should be by Vanessa Caceres EyeWorld Contributing Writer Review of autologous serum for dry eye finds more research needed Slit lamp photo of a patient with severe dry eye. Fluorescein staining of the cornea demonstrates significant punctate epithelial erosions inferiorly. Pre-corneal tear film is almost non-existent. Source: Esen K. Akpek, MD continued on page 104 88-107 Cornea_EW March 2014-DL2_Layout 1 3/6/14 3:47 PM Page 102

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