Validation of the Glaucoma Quality of Life-15 Questionnaire in Serbian language

AIM：To translate the Glaucoma Quality of Life-15（GQL-15）to Serbian language and asses its validity and reliability in the population of Serbian patients.METHODS：The study included 177 glaucoma patients.Clinical parameters（visual acuity,mean defect and square root of loss variance of visual field）and socio-demographic data were collected.Patients were stratified according to the Nelson’s glaucoma staging system as mild,moderate and advanced glaucoma.All patients filled out the GQL-15 and National Eye Institute Visual Function Questionnaire（NEI-VFQ 25）.The GQL-15 was translated following the internationally-accepted methodology,and its psychometric properties were assessed by using classical test theory and Rasch analysis.RESULTS：The mean total score for the GQL-15 was 20.68±7.31.The Cronbach’s alpha coefficient for the whole scale was 0.89（central and near vision,α=0.24;peripheral vision,α=0.85;glare and dark adaptation,α=0.83）.Factor analysis established 4 factors（70.3% of variance）：two corresponding to the original factors and two new factors specific for the Serbian population.The GQL-15 score correlated positively with almost all clinical parameters and NEI-VFQ 25 proving good criterion validity.Correlation of the GQL-15 total score on test-retest confirmed appropriate scale reproducibility（ρ=0.96,P〈0.001）.The GQL-15 discriminated well advanced from mild and moderate glaucoma.In Rasch analysis we obtained adequate item（0.95）reliability index.Almost all items had infit and outfit mean squares in the accepted range.CONCLUSION：Serbian version of the GQL-15 demonstrates adequate reliability and validity.This version of the GQL-15is a valid instrument for evaluation of quality of life among Serbian speaking patients with glaucoma and can be applied in daily clinical work.

Agreement in identification of glaucomatous progression between the optic disc photography and Heidelberg Retina Tomography in young glaucomatous patients

AIM:To evaluate concordance between the clinical assessment of glaucomatous progression of the optic disc photography and progression identified by Heidelberg Retina Tomograph(HRT)in patients with suspected primary juvenile open angle glaucoma(JOAG).METHODS:Optic disc photographs and corresponding HRTⅡseries were reviewed.Optic disc changes between first and final photographs were noted as well as progression identified by HRT topographic change analysis(TCA)and rim area regression line(RARL)Agreement between progression indentified by photography and HRT methods was assessed.Progression,determined from optic disc photographs by consensus assessment was used as the reference standard.RESULTS:A total of 31 patients(59 eyes)with suspected JOAG were studied.Agreement for progression/no progression between TCA and photography was obtained in 4 progressing eyes and 38stable eyes(71.19%,k=0.11).Agreement for progression/no progression between RARL and photography was detected in 5 progressing eyes and in 34 stable eyes(66.10%,k=0.15).The number of HRT per patient was statistically higher in the progressing group(P=0.034).CONCLUSION:Agreement for detection of longitudinal changes between photography and HRT analysis was poor.One way to improve the chance of discovery of the progression could be increasing the number of HRT examinations.