Mehdi Alizadeh - Assistant Professor, Department of Ophthalmology, School of Medicine Hamadan University of Medical Sciences & Health Services, Hamadan, Iran
fatemeh Eslami - Assistant Professor, Department of Ophthalmology, School of Medicine Hamadan University of Medical Sciences & Health Services, Hamadan, Iran
Pegah Zamanian - Assistant Professor, Department of Ophthalmology, School of Medicine Hamadan University of Medical Sciences & Health Services, Hamadan, Iran

Purpose: Study on frequency and association of co-existing connective tissue disease and other risk factors in patients with keratoconus referred to Farshchian hospitalMethods: the aim of this study was to determine the frequency and correlation between the association of connective tissue diseases and other risk factors for keratoconus in patients with keratoconus which went to Farshchian Hospital between 1395 to 1396 to prevent and take action in the case of illness Results: The mean age of people was 21.96 years . Mean age of diagnosis the disease was 20.81 years . The average duration of keratoconus was 10.46 months. 43.8% of cases were pupil-student in terms of job status. In 31.2% of cases, keratoconus was related to first-degree relatives. 53.1% had no co-existing disease and 46.9% had one or more of accompanying abnormalities. The most common association was with atopy and then mitral valve prolapse (respectively 18.8% and 5 cases 15.6%. The incidence of each of the following diseases including cutaneous infection, ichthyosis, Down syndrome, Marfan syndrome and cataract was 3.1% .floppyl eyelid syndrome included 12.5% . 26 cases (81.2%) in the right eye and 24 cases (75%) in the left eye, had moderate severity of keratoconus.However, the relationship between duration of keratoconus and severity of disease in the left eye was statistically significant , but this was not significant in both eyes , but overall, with an increase time of suffering from the disease itbecomes more severe Conclusion: prevalence of atopy in keratoconus patients is higher than normal population. The prevalence of mitral valve prolapse is higher than that of the normal population. In the case of mitral prolapse, the risk of an increase in keratoconus intensity is higher. And with the identification of most patients in the moderate stage, it is advisable to use appropriate screening methods at an early age for early diagnosis of the disease.