en چشم Ophthalmology پژوهشي Research <strong>Introduction:</strong> Intravitreal Avastin (bevacizumab) injection is reportedly accompanied by ocular and systemic side-effects. Our enquiry assesses whether there are any differences between intraocular pressure (IOP) in baseline and on the day after injection in patients treated for retinal disease.<br> <strong>Methods:</strong> In this experimental study, 82 eyes with retinal diseases that had indication for anti-VEGF and were treated with injections of intravitreal bevacizumab were taken as the case group, and 82 healthy eyes were considered as controls. The IOP was measured by non-contact tonometry in both the healthy eyes and the eyes with retinal diseases before and 24 hours after intervention. Data were analyzed by paired t test and independent t-test in SPSS 19.0 software. Significance level was set at P <0.05.<br> <strong>Results:</strong> Results of the study showed that the mean IOP before injection was not significantly different in either groups (p=0.51). However, it was significantly lower after injection than before it in both case and control eyes (p<0.01). The mean IOP changes before and after infusion in the case and control eyes did not differ significantly (p=0.30).<br> <strong>Conclusions:</strong> Our study did not find an increased IOP in bevacizumab-treated eyes when compared to fellow control eyes. Further studies with a greater sample size are needed to evaluate whether an increased number of ranibizumab injections is associated with IOP changes. Bevacizumab, Intraocular pressure, Intravitreal Injections 44 46 http://jsurgery.bums.ac.ir/browse.php?a_code=A-10-72-1&slc_lang=en&sid=1 Behrooz Heydari hb51958@yahoo.com 10031947532846003286 10031947532846003286 Yes Assistant Professor, Department of Ophthalmology, Faculty of Medicine, Birjand University of Medical Sciences, Birjand, Iran Saeed Reza Heydari heydarisr29@gmail.com 10031947532846003287 10031947532846003287 No Department of Optometry, Faculty of Optometry, Mashhad University of Medical Science, Mashhad, Iran Gholamhossein Yaghoobi yaqubig@yahoo.com 10031947532846003288 10031947532846003288 No Professor, Department of Ophthalmology, Faculty of Medicine, Birjand University of Medical Sciences, Birjand, Iran