Analysis of retinal nerve fiber layer thickness and macular thickness in unaffected female carrier of Leber hereditary optic neuropathy / 中华实验眼科杂志

ABSTRACT

Background Researches documented that retinal nerve fiber layer thickness (RNFLT) in unaffected carriers of Leber hereditary optic neuropathy (LHON) becomes thickened in different quadrants to different degrees.But the change of their macular thickness is still unclear.Objective This study was to clarify RNFLT and macular thickness by optical coherence tomography (OCT) in unaffected female carriers of LHON families.Methods Five female LHON patients (5 eyes) from 5 LHON families,eighteen unaffected female carriers (18eyes) from 18 LHON families and twenty-five age-matched healthy female controls (25 eyes) were included in this study.The patients and genetic carriers were diagnosed in PLA General Hospital from 2011 September to 2012 October.Regular ocular examination were performed followed by OCT measurement of retinas.The Optic Disc Cube 200×200 and Macular Cube 200×200 protocols were used during the OCT measurement.Average (360°) RNFLT,RNFLT at four quadrantic sections,cube average macular thickness and macular thickness of nine Early Treatment Diabetic Retinopathy Study (ETDRS) sub-areas were compared among the LHON genetic carriers,LHON patients and normal controls.Results Compared to the normal control group,significant reduced values were seen in temporal,superior,nasal and inferior side of sub-area macular thickness in the LHON female carriers (P=0.022,0.046,0.024,0.008).In addition,but no significant differences were found in cube average thickness,central subarea macular thickness,temporal,superior,nasal and inferior side of lateral sub-area macular thickness,average RNFLT,and temporal,superior,nasal and inferior quadrant RNFLT between the LHON female carriers and normal controls (P=0.102,0.051,0.238,0.663,0.1 10,0.104,0.419,0.371,0.158,0.063,0.563).Compared to the unaffected female carrier group,female patients showed significant reductions in cube average macular thickness,temporal,superior,nasal and inferior side of sub-area macular thickness,temporal,superior,nasal and inferior side of lateral sub-area mac ular thickness,average R NFLT and temporal,superior,and inferior quadrant RNFLT (P =0.000,0.000,0.000,0.007,0.002,0.002,0.000,0.000,0.040,0.000,0.016,0.000,0.000) except for the central subarea macular thickness and nasal quadrant RNFLT (P=0.388,0.580).Conclusions Unaffected LHON female carriers show a normal peripapillary RNFLT,but the macular thickness at medial sub-area is thinner.This first report offers an information of macular structure change in unaffected LHON female carriers,which suggest that macular damage appears prior to RNFLT change.