Aim of the work: this study aimed to evaluate changes in photoreceptors, inner segment/outer segment (IS/OS) junction and external limiting membrane (ELM) following grid argon laser versus intravitreal injection of antivgef ( Ranibizumab ) in diabetic type2 patients affected by clinically significant macular edema.
Methods: forty eyes of diabetic type2 patients who were affected by clinically significant macular edema were randomly categorized into two groups( Group treated by argon grid laser and group treated by intravitreal injection of antivgef for the first time) both groups were investigated for best corrected visual acuity (BCVA) and the integrity of the photoreceptors, IS/OS and ELM as being (Continuous(+), interrupted( ±) or Absent (-) ) by spectral-domain optical coherence tomography (SD-OCT)( CIRRUS HD-OCT) before treatment , 1month, 2months and 3months after treatment . Other variables, included central macular thickness (CMT) and central macular volume (CMV) were evaluated. Results: significant difference was found between [photoreceptor, is/os] (+), photorecptor, is/os (+,-) and photoreceptor, is/os (-) groups in BCVA at baseline; it was 0.61,0.73,and 1 and after 6 months it was 0.48,0.73 and 1 . Results were similar for ELM groups. Signiant difference was found between ELM (+), ELM (+,-) and ELM (-) groups in BCVA at baseline it was 0.59,0.72,and 1 and after 6 months it was 0.46,0.68 and 1 in lucentis group and signiant difference was found between photoreceptor, is/os (+) and photorecptor ,is/os (+,-) groups in BCVA at baseline was(0.32and 0.3 and after 6 months it was 0.27and 0.3 . Results were similar for ELM groups. Signiant difference was found between ELM (+) and ELM (+,-) groups in BCVA at baseline it was 0.29 and 0.5 and after 6 months it was 0.25 and 0.4 in argon laser group
Conclusion: the more damage of outer retinal layers at the time of DME the lower visual acuity following DME resolution and the presence of intact of these layers is an important factor in determining final visual acuity.