The aim of this study is to compare the effect of tropicamide 0.5% and tropicamide 1% on intraocular pressure and anterior chamber parameters in patients with Diabetes Mellitus.

Patients with diabetes type 1 and type 2 older than 21 years of age, in the specialized clinic of Kowsar Hospital (Semnan University of Medical Sciences) are examined. Eligible individuals enter the study and are randomly assigned to group 1 or group 2. In each group, visual acuity measurement, slit lamp biomicroscopy and fundus examination are performed. Intraocular pressure is measured with Goldmann applanation tonometer. pupil size, refraction and keratometry are measured with two different autorefractokeratometers. keratometry, pupil size and other anterior chamber parameters are also evaluated by Oculus Pentacam imaging. Then, the patients receive tropicamide 0.5% drops in group 1 and tropicamide 1% drops in group 2. 30 minutes later, all previous measurements are repeated. Patients and the ophthalmologist and the data analyzer are unaware of the drug type.

Inclusion Criteria:

• Patients with Diabetes Mellitus type 1 and 2

Exclusion Criteria:

• Proliferative diabetic retinopathy
• History of cataract surgery
• severe nuclear and cortical cataract
• Glaucoma
• Intraocular pressure (IOP) greater than 21 mmHg
• Familial history of glaucoma
• Narrow angle (Van Herick 1, 2)
• Cup to disc ratio greater than 0.5
• Pregnancy
• Pterygium
• Corneal ectasia
• History of keratorefractive surgery
• Corneal dystrophy
• Iris disorders
• Anisocoria
• Iris neovascularization
• Use of miotics or mydriatics

Data can be shared without disclosing the identities of the participants.

Access period starts one year after the results are published.

Researchers can use the data for systematic review studies and meta-analysis. Researchers working in academic and scientific institutions can contact the person in charge of the scientific inquiries of the project by e-mail. After receiving the request e-mail, if the person is eligible, the data will be sent

The drops are instilled into the patients' eye by a nurse. Study participants are unaware of the type of medication used. The outcome assessor (ophthalmologist) does not know the type of medication used for each patient. The data is analyzed by an biostatistician. He or she also does not know the type of drug used for each patient.