RESEARCH ARTICLE Quantitative phase imaging of erythrocyte in epilepsy patients Aysun Ünal 1 | Özlem Kocahan 2 | Bengü Altunan 1 | Aslı Aksoy Gündo  gdu 1 | Merve Uyanık 2 | Serhat Özder 3 1 Department of Neurology, Tekirda g Namık Kemal University, Tekirdag, Turkey 2 Department of Physics, Tekirda g Namık Kemal University, Tekirdag, Turkey 3 Department of Physics, Çanakkale Onsekiz Mart University, Çanakkale, Turkey Correspondence Özlem Kocahan, Department of Physics, Tekirdag Namık Kemal University, Tekirda g, Turkey. Email: okocahan@nku.edu.tr Funding information Tekirdag Namık Kemal University Scientific Research Project Commission, Grant/Award Number: NKUBAP.02.GA.19.230; Turkish Scientific and Technical Research Council, Grant/Award Number: 115F168 Abstract The present study focuses on the quantitative phase imaging of erythrocytes with the aim to compare the morphological differences between epilepsy patients under antiepileptic treatment, who have no other disease which may affect the erythrocyte morphology, and the healthy control group. The white light diffraction phase micros- copy (WDPM) has been used to obtain the interferogram of the erythrocyte surfaces. The continuous wavelet transform with Paul wavelet has been chosen to calculate the surface profiles from this interferogram image. For the determination of alter- ation in morphology, besides WDPM, erythrocyte surfaces have been investigated by light microscope and scanning electron microscope. In this way, it has been possi- ble to see the difference in terms of precision and implementation between the most commonly used methods with regard to the quantitative phase imaging. Erythrocytes from all the samples have been examined and displayed in both two- and three- dimensional way. We have observed that erythrocytes of patients with effective anti- epileptic blood levels were more affected in morphology than healthy subjects. When we compared the erythrocyte morphological changes of patients who received mon- otherapy or polytherapy, no difference was observed. In conclusion, antiepileptic drugs (AEDs) cause red blood cell (RBC) morphological changes and a combined usage of WDPM with Paul wavelet and light microscopy methods are very conve- nient for studying the erythrocyte morphologies on multiple patients. KEYWORDS epilepsy, erythrocyte morphology, light microscopy, scanning electron microscopy, white light diffraction phase microscopy 1 | INTRODUCTION In recent years, research on cell surface has gained importance in bio- medical optical measurement studies. Red blood cells (RBC), or eryth- rocytes, representing discoid cells with thick rim and thin sunken center, are the most abundant among blood cells. Different blood abnormalities at different stages alter the original biconcave shape of erythrocytes into different morphologies (Ahmadzadeh, Jaferzadeh, Lee, & Moon, 2017; Jaferzadeh & Moon, 2016; Moon et al., 2013; Singh, Srivastava, & Mehta, 2020). Apart from studies on clustering irregular shapes of erythrocytes at different duration of storage from the sample collected from healthy person (Ficarra et al., 2013; Piety, Reinhart, Pourreau, Abidi, & Shevkoplyas, 2016; Suwalsky et al., 2004; Suwalsky, Mennickent, Norris, Villena, & Sotomayor, 2006), there are various other articles investigating the erythrocyte morphologies from the sample collected from patients (Buys et al., 2013; Kurantsin-Mills, Samji, Moscarello, & Boggs, 1982; Oprisan, Stoica, & Avadanei, 2017). The effects of the antiepileptic drugs (AEDs) on erythrocyte morphol- ogy have been studied in vitro (Ficarra et al., 2013; Suwalsky et al., 2006). Here, erythrocyte surface observations were generally performed with scanning electron microscopy (SEM) and atomic force microscopy (AFM; Mukherjee, Saha, Routray, & Chakraborty, 2015). Received: 29 September 2020 Accepted: 6 December 2020 DOI: 10.1002/jemt.23676 Microsc Res Tech. 2020;1–9. wileyonlinelibrary.com/journal/jemt © 2020 Wiley Periodicals LLC 1