title: Regional assessment of cone system function following uncomplicated retinal detachment surgery.
abstract: OBJECTIVE
  To evaluate regional cone system function after uncomplicated retinal detachment (RD) surgery, by recording focal electroretinograms (FERGs) from the central and paracentral regions of the posterior pole.
  
  
  METHODS
  FERGs in response to either a central (eccentricity: 0-2.25 deg) or a paracentral annular (2.25-9 deg) uniform field, presented on a light adapting background and sinusoidally flickered at 41 Hz (95% modulation depth, 93 cd/m(2) mean luminance) were recorded from 16 eyes (16 patients) 2 weeks to 420 months following uncomplicated RD surgery (encircling procedure with or without scleral buckling). Pre-operatively, 10 out of 16 eyes had a macular RD. Mean time elapsed from onset of symptoms to surgery was 20 days (range: 5-90 days). Post-operatively, visual acuity ranged 0.1 to 1.0. Eight age-matched normal subjects served as controls. Amplitude and phase of the FERG fundamental harmonic were measured.
  
  
  RESULTS
  Compared to control eyes, affected eyes' central and paracentral FERGs were on average reduced in amplitude (by 40% and 28%, respectively, p<0.01) and delayed in phase (by 70 and 100 degrees, respectively, p<0.01). Eyes with a macular RD did not differ in FERG amplitude or phase from eyes that had a peripheral RD. In individual affected eyes, central, but not paracentral FERG amplitudes were negatively correlated (p=0.05) with time elapsed from onset of symptoms to surgery.
  
  
  CONCLUSIONS
  Central and paracentral cone system dysfunction may be detected even at lengthy time intervals from retinal reattachment, independent of the presence of a pre-operative macular RD. The extent of central loss appears to be inversely related to RD duration, in agreement with previous reflectometric findings on foveal cone photopigment density [Liem et al., 1994; Ophthalmology 10: 1945-51].
authors.affiliation: Institute of Ophthalmology, Catholic University, Rome, Italy.
authors.forename: Lucrezia
authors.initials: L
authors.lastname: Montrone
authors.forename: Lucia
authors.initials: L
authors.lastname: Ziccardi
authors.forename: Giovanna
authors.initials: G
authors.lastname: Stifano
authors.forename: Marco
authors.initials: M
authors.lastname: Piccardi
authors.forename: Fernando
authors.initials: F
authors.lastname: Molle
authors.forename: Francesco
authors.initials: F
authors.lastname: Focosi
authors.forename: Antonello
authors.initials: A
authors.lastname: Fadda
authors.forename: Benedetto
authors.initials: B
authors.lastname: Falsini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004596:Electroretinography; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D013508:Ophthalmologic Surgical Procedures; D011184:Postoperative Period; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D012163:Retinal Detachment / Q000503:physiopathology / Q000601:surgery*; D014792:Visual Acuity