Effect of Menopause on the Ocular Protection Index (OPI) in a population of Dry Eye Patients

Abstract

Purpose. It has been shown that the interaction of the time between blinks or the Inter-Blink Interval (IBI) and tear film break-up time (TFBUT) helps maintain the integrity of an ocular surface. A protected surface exists when the TFBUT matches or exceeds the IBI. In contrast, an unprotected surface exists when TFBUT is less than the IBI. This is clinically relevant since repeated intermittent exposure of a tear film deficient cornea can lead to ocular discomfort and the development of clinical signs such as keratitis and redness. The relationship between TFBUT and IBI has been quantified by the Ocular Protection Index (OPI) which is calculated by dividing TFBUT by IBI. If the OPI is < 1, a patient is at risk and if the OPI is 1, a patient is not. The OPI has proven to be useful in assessing the factors that can cause and / or exacerbate dry eye. The purpose of this study was to evaluate the effect of menopause on the OPI in a population of dry eye patients compared to age-matched males. Methods. One-hundred and six (106) females and 118 males diagnosed with dry eye underwent ophthalmic examinations including visual acuity, blink rate, TFBUT, and fluorescein staining. An OPI was determined and compared between the pre and post menopausal patients and age-matched male groups. Results. The mean OPI in pre menopausal patients, mean age of 42 ± 7 years (N=44), was 1.32 (± 1.25). The mean OPI in post menopausal patients, mean age of 66 ± 8 years (N=62), was 0.75 (± 0.50). The mean OPI for male patients, mean age of 41 ± 11 years (N=44), was 1.02 (± 0.52). The mean OPI for male patients, mean age of 69 ± 8 years (N=74), was 1.16 (± 1.00). The mean OPI in post menopausal patients was significantly lower than in pre menopausal subjects (p=0.0015). The mean OPI in post menopausal patients was significantly lower than the age matched male patients (p=0.0038). Conclusions. In this patient population, post menopausal dry eye patients have a lower OPI score (a mean OPI <1), or an unprotected ocular surface, putting them at greater risk of exacerbating the signs and symptoms of dry eye. The data suggest that menopause has an impact on OPI. MYOFIBROBLAST GENERATION CORRELATES WITH SURFACE IRREGULARITY AFTER PRK. Steven E. Wilson, Marcelo V. Netto, Rajiv R. Mohan. The Cole Eye Institute, The Cleveland Clinic Foundation, Cleveland, OH, USA.