Background: Glaucoma is a cause of permanent blindness and occurs most often in older adults. Although glaucoma can be initially managed by conservative treatments, trabeculectomy, initially described by has traditionally been considered the "gold standard" for filtration surgery. Objective: To investigate the effect of trabeculectomy on corneal topography, anterior chamber depth, and aberrations by a SIRIUS topography.Patients and Methods: The present study was a prospective cohort study including 30 eyes of patients who were scheduled to undergo trabeculectomy at Ophthalmology Department of Al Azhar university hospital during the period from January 2018 to August 2019. Results: In the present study, we compared included eyes according to site of flap midway (between K1&K2) versus vertical flap (on K). We found no statistically significant differences between studied groups in terms of K1 (p =0.29), K2 (p =0.33), and astigmatism values (p =0.38).In our study, there was statistically significant difference between pre and postoperative values of ACD (p < 0.001). Eyes showed statistically significant decrease in ACD postoperatively. Conclusions: Trabeculectomy surgery can cause changes in keratometry values, aberrations and ACD. These changes can be significant enough to affect visual acuity, the accuracy of IOL power calculation, and refractive outcomes after combined or future cataract surgery.