Retinal nerve fibre layer of perimetrically unaffected eyes of glaucoma patients: an optical coherence tomography study.
OBJECTIVE
The aim of this study is to evaluate whether optical coherence tomography (StratusOCT) may detect early changes in perimetrically unaffected (PU) fellow eyes of glaucomatous patients by assessing retinal nerve fibre layer (RNFL) thickness parameters.


METHODS
Thirty-seven glaucomatous patients with unilateral field loss and 34 age-matched controls were recruited. In glaucoma patients, PU and perimetrically affected fellow eyes were analysed separately. For each group, mean values (+/-SD) of RNFL thickness parameters were calculated and comparisons between fellow eyes of glaucoma patients and between healthy and PU eyes of glaucoma patients conducted with paired t-test and Mann-Whitney U-test, respectively. Proportion of clock-hour sectors flagged with probability <5% or <1% was collected and differences between healthy and PU eyes were evaluated on Fisher exact test.


RESULTS
Global (Average Thickness) and sectoral parameters (Inferior and Nasal Average), Maximum thickness-minimum thickness (Max-min), as well as 2-o'clock (nasal side) and 6-o'clock sectors resulted significantly thinner in PU eyes than in control group. Proportion of eyes with clock-hour position flagged with probability <5% or <1% was not significantly different between healthy and PU eyes.


CONCLUSIONS
Despite a standard automated perimetry within normal limits, the StratusOCT detected both localized and diffuse RNFL thinning in PU eyes of glaucoma patients. These eyes should be considered at risk of developing functional damage over time and consequently require thorough monitoring for detecting any sign of progression.
Da Pozzo
Stefano
S
Eye Clinic, University of Trieste, Trieste, Italy. stefanodapozzo@yahoo.it
Fanni
Daniela
D
Paoloni
Marco
M
Trovarelli
Sara
S
Ravalico
Giuseppe
G
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology