Background: The international Dry Eye Workshop 2007 (DEWS) defined dry eye syndrome (DES) as “a multifactorial disease of the tear and ocular surface that results in symptoms of discomfort, visual disturbance, and tear film instability with potential damage to the ocular surface. It is accompanied by increased osmolarity of the tear film and inflammation of the ocular surface”(DEWS, 2007a). DES is very common, affecting a significant percentage of the population, especially those older than 40 years with prevalence estimates ranging from approximately 10-30% of the population in the United States (Foster, 2015) to 27.5% (Lee, 2002) in rural Indonesia and 18.4% (Sahai, 2005) in India. In Uganda, DES is common but there is no national prevalence data available. Hospital data at Ruharo Eye Center shows that about 672 patients out of the 7726 adults who presented for eye care services in 2015 were diagnosed with DES and of these, 416 were 40 years and above (unpublished).The McMonnies questionnaire is among the earliest and most widely used screening instruments for DES and it was found to be a useful tool in detecting the presence of dry eye disease and those at risk of developing the disease(Erickson, 2002)In our current practice, diagnosis of DES is mainly symptomatic leaving many asymptomatic patients untreated which calls for the need for an easy to use and inexpensive screening tool (Erickson, 2002).
Aim: To determine the sensitivity and specificity of McMonnies questionnaire in diagnosing and grading the severity of DES among patients who are 40 years and above attending REC.
Design and methods: This was a cross-sectional hospital-based study conducted during the months of September and December 2017. We included both males (76) and females (91) who were 40 years and above using convenient sampling. All participants were screened for DES using MQ after which assessment for the signs of DES using Schirmer I, TBUT and Rose Bengal tests were done. We entered data into Excel and exported into Stata 13 for analysis.
Results: A total of 167 patients were enrolled and 91 (54.49%) were females. The female to male ratio was 1.2:1. The median age of the patients was 63 years (IQR 54-72 range 40-94). Most of the patients underwent some form of education 111 (66.47) while the remaining 56 (33.35%) had no formal education. The majority, 124 (74.25) were peasants. The median Schirmer I and TBUT scores were 14 mm (IQR 5-22 range of 1-35) and 6.67 seconds (IQR 3.33-17, range of 1-34.33) respectively and that of MQ was 12 (IQR 9-17 range of 2-27).The proportion of patients with DES was 68% as determined by the composite score and the biggest proportion, 111 (66.47%) had mild/moderate DES, 54 (32.34%) were normal while 2 (1.19%) had severe DES. The sensitivity and specificity of McMonnies questionnaire in diagnosing DES were 81.6% (95% CI, 73.2 - 88.2) and 39.6% (95% CI, 26.5 - 54) respectively and for grading DES severity were 61.1% and 18.6% for normal; 63.6% and 40.4% for mild/moderate and 50% and 87.9% for severe as shown below.
Conclusion: The proportion of patients with DES was high, (68%). The MQ proved to be a good screening tool with a sensitivity and specificity of 81.3% and 36.9% respectively; however, it yielded poor results when it came to grading the severity of DES. We therefore recommend routine screening of patients in this age group for DES using MQ but advice against using it as a grading tool.