Abstract
Purpose:
To investigate the visual and structural prognosis of the untreated initial non-glaucomatous fellow eyes of unilateral normal tension glaucoma (NTG) patients.
Methods:
NTG patients with unilateral visual field (VF) loss and no visual field defect, retinal nerve fiber layer (RNFL) defect or neuroretinal rim (NRR) notching in the fellow eyes and those who had initial non-glaucomatous fellow eyes not treated were included. For the fellow eyes of the 50 subjects, the development of VF defect, RNFL defect, and NRR notching was inspected retrospectively by two observers. Baseline clinical characteristics including initial intraocular pressure (IOP), central corneal thickness, and spherical equivalent were compared between glaucomatous and contralateral eye.
Results:
The mean follow-up period was 8.77±2.92 years. Among 50 unilateral NTG patients 5 (10%) patients developed RNFL defect in 5.55±2.69 years and 4 (8%) patients developed NRR notching in 5.17±3.09 years in the fellow eye. Among 6 (12%) patients who had developed either RNFL defect or NRR notching, only 3 (6%) patients developed VF loss in 1.81 years, 3.09 years, and 9.27 years, respectively. Initial IOP was significantly higher (17.20±3.07 mmHg vs 16.58±3.24 mmHg, p=0.031), SE was more myopic (-1.81±2.27 D vs -1.40±2.14 D, p=0.025), and the occurrence of disc hemorrhage (15/50 vs 6/50, p=0.049) was significantly higher in the glaucomatous eye than the contralateral eye.
Conclusions:
The incidence of glaucoma development in the fellow eye is rather low, and even glaucoma develops in the fellow eye, it takes quite a long period of time. Therefore, the initial non-glaucomatous fellow eye of the unilateral NTG patient may be observed without treatment until the glaucoma develops.
Keywords: 758 visual fields •
610 nerve fiber layer •
627 optic disc