title: Correlation between retinal sensitivity and cystoid space characteristics in diabetic macular edema.
abstract: OBJECTIVE
  To evaluate the correlation between retinal sensitivity and cystoid space characteristics in eyes with diabetic macular edema (DME).
  
  
  METHODS
  Prospective cross-sectional study of 22 subjects with DME (32 treatment-naïve eyes). All study subjects underwent complete ophthalmic examination, including slit-lamp biomicroscopy and dilated fundus examination. All subjects underwent spectral domain optical coherence tomography (SD-OCT) and microperimetry (MP). Intraretinal cystoid space (ICS) volume was generated after manual delineation of cystoid space boundaries using the three-dimensional-OCT software. Various SD-OCT parameters, including retinal thickness, retinal volume, cystoid space volume, cystoid space intensity, and outer retinal structure integrity, were correlated with MP parameters and best-corrected visual acuity (BCVA).
  
  
  RESULTS
  Subject's mean age was 57 ± 9 years. The mean logarithm of minimum angle of resolution BCVA was 0.4 ± 0.2. The intraclass correlation coefficient for inter- and intra-grader assessment of cystoid space volume by manual delineation was 0.99 and 0.99, respectively. Mean total ICS volume was 0.4 ± 0.4 mm 3 and for the foveal center, subfield was 0.1 ± 0.1 mm 3 . Mean retinal sensitivity was 12.89 ± 10 dB; however, foveal retinal sensitivity was 12.3 ± 11.1 dB. We found no significant correlation between BCVA and total cystoid space volume (r = 0.33, P = 0.06). Correlation between total retinal sensitivity and total ICS was negative and nonsignificant (r = -0.17, P = 0.36). Correlation between foveal retinal sensitivity and foveal cystoid space intensity was moderate and marginally significant (r = -0.43, P = 0.05).
  
  
  CONCLUSIONS
  Total cystoid space volume was not significantly correlated with BCVA or total retinal sensitivity in subjects with DME. Foveal cystoid space optical intensity was negatively correlated with foveal retinal sensitivity. These findings suggest further investigation of cystoid space characteristics in the setting of DME may be of value.
authors.affiliation: Department of Ophthalmology, Doheny Eye Institute, University of Southern California, Los Angeles, California, USA.
authors.forename: Swetha B
authors.initials: SB
authors.lastname: Velaga
authors.affiliation: Department of Ophthalmology, Doheny Eye Institute, University of Southern California, Los Angeles, California, USA.
authors.forename: Muneeswar G
authors.initials: MG
authors.lastname: Nittala
authors.affiliation: Smt. Kanuri Santhamma Retina Vitreous Centre, L. V. Prasad Eye Institute, Hyderabad, Telangana, India.
authors.forename: B
authors.initials: B
authors.lastname: Parinitha
authors.affiliation: Department of Ophthalmology, Doheny Eye Institute, University of Southern California, Los Angeles, California, USA.
authors.forename: S R
authors.initials: SR
authors.lastname: Sadda
authors.affiliation: Smt. Kanuri Santhamma Retina Vitreous Centre, L. V. Prasad Eye Institute, Hyderabad, Telangana, India.
authors.forename: Jay Kumar
authors.initials: JK
authors.lastname: Chhablani
mesh_terms: D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D003930:Diabetic Retinopathy / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008269:Macular Edema / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012160:Retina / Q000473:pathology / Q000503:physiopathology*; D041623:Tomography, Optical Coherence; D014792:Visual Acuity