AIM: To observe the photoreceptor integrity by spectral-domain optical coherence tomography(SD-OCT)in diabetic macular edema(DME)with or without serous retinal detachment(SRD), and assess their association with visual acuity.

METHODS: In this prospective study, consecutive patients were observed by SD-OCT with central subfield mean thickness(CSMT)≥300μm and without definite macular traction or compact hard exudates in central 500μm. They were divided into two groups: with or without SRD. The integrity of photoreceptor was observed in the central 500μm. The integrity of external limiting membrane(ELM)in all eyes and the integrity of inner and outer segments(IS/OS)in eyes without SRD was classified as existent or completely absent. In SRD eyes, the integrity of IS/OS was classified into another two grades: preserved or atrophic. BCVA between different integrity of IS/OS or ELM were compared.

RESULTS: In all the 56 eyes of 41 patients, there were 32 eyes detected without SRD and 24 eyes with SRD. In eyes without SRD, BCVA was significantly poorer in eyes with completely absent IS/OS or ELM than those with existent IS/OS or ELM(t=-7.938, P=0.000; t= -7.347, P=0.000). In eyes with SRD, BCVA was also significantly poorer in eyes with atrophic IS/OS than those with preserved IS/OS(t=-4.354, P=0.000), but there was no significant difference in BCVA between eyes with or without completely absent ELM(t=-0.895, P=0.381).

CONCLUSION: In patients of diabetic macular edema, the integrity of subfoveal IS/OS was closely related to BCVA. But the associations between the integrity of ELM and BCVA might not consistent in eyes with or without SRD.