Abstract
Purpose: :
To investigate any associations between the stage of visual field loss (VFL) and the maximum intraocular pressure (IOPmax), the age at first clinical examination, age at diagnosis (AAD), family history of glaucoma (FHG), cup to disc ratio (CDR), gender, vasospasm (VA) and migraine (MI). Which parameters are significantly associated with a more severe visual field damage?
Methods: :
Retrospective evaluation of 381 patients with Normal Tension Glaucoma (NTG) with VFL stage I–V (Aulhorn classification) or preperimetric NTG. For staging the eye with the more severe VFL was used. If both eyes had the same stage of VFL (33,5%) the selected eye was included at random. IOP: Consistently equal to or less than 21 mmHg on diurnal testing, with no single measurement higher than 24 mmHg during follow up. In USA 58.2% were examined and 41.8% in Germany. There was information on AAD in 270, CDR in 370, yes or no answer on MI in 89 and on VA in 78 patients. The 289 patients with IOP max 21 mmHg during the entire observation time with VFL in all patients were used for comparison with control groups of 136 NTG and 1241 POAG patients evaluated prospectively by means of a questionnaire for comparison of FHG, AAD, MI, and VA. For statistics the Yonckheere–Terpstra Test was used.
Results: :
22.1% of 381 eyes had a preperimetric NTG, stage I had 10.5%, stage II 12.9%, stage III 39.3%, stage IV 12.1%, stage V 3.1%. 148 of 289 eyes with VFL (51.8%) had a stage III. Stage III was most frequent at the first examination in all age groups. Associations with stage of VFL were found with the age at first examination (p=0.001), AAD (p=0.002), which was not different between females (p=0.0024) and males (p=0.016), visual acuity (p=0.001), CDR (p=0.001) and IOPmax up to 24 mmHg (p=0.005) and, in contrast to the control group, in MI (p=0.026). No significant association with the stage of VFL was found for IOP within the group with IOPmax 21 mmHg (p=0.456), for VA (p=0.571) and for FHG (p=0.190).
Conclusions: :
NTG has a female preponderance (242 of 381, 62.8%), but females did not show severe stages of VFL more frequently than males. NTG is, compared to AAD in the POAG control group, not a disease of the elderly, but a disease with more severe VFL on late detection . Increasing age, larger CDR and MI are associated with more advanced VFL. FHG does not influence VF prognosis.
For NTG we found in former studies a possibly heritable 20% larger CDR compared to POAG in stage I and II of VFL. FHG of 36.6% and of 34% in the control group suggests a genetic component in the pathogenesis.
Keywords: clinical (human) or epidemiologic studies: risk factor assessment