scholarly journals Patterns of functional vision loss in glaucoma determined with archetypal analysis

2015 ◽  
Vol 12 (103) ◽  
pp. 20141118 ◽  
Author(s):  
Tobias Elze ◽  
Louis R. Pasquale ◽  
Lucy Q. Shen ◽  
Teresa C. Chen ◽  
Janey L. Wiggs ◽  
...  

Glaucoma is an optic neuropathy accompanied by vision loss which can be mapped by visual field (VF) testing revealing characteristic patterns related to the retinal nerve fibre layer anatomy. While detailed knowledge about these patterns is important to understand the anatomic and genetic aspects of glaucoma, current classification schemes are typically predominantly derived qualitatively. Here, we classify glaucomatous vision loss quantitatively by statistically learning prototypical patterns on the convex hull of the data space. In contrast to component-based approaches, this method emphasizes distinct aspects of the data and provides patterns that are easier to interpret for clinicians. Based on 13 231 reliable Humphrey VFs from a large clinical glaucoma practice, we identify an optimal solution with 17 glaucomatous vision loss prototypes which fit well with previously described qualitative patterns from a large clinical study. We illustrate relations of our patterns to retinal structure by a previously developed mathematical model. In contrast to the qualitative clinical approaches, our results can serve as a framework to quantify the various subtypes of glaucomatous visual field loss.

2019 ◽  
Vol 12 (3) ◽  
pp. e227803
Author(s):  
Nayomi Perera ◽  
Melissa Shields ◽  
Marlon Perera ◽  
Paul A Adler

A 78-year-old man with vascular risk factors and a family history of glaucoma presents with bilateral superior arcuate visual field loss. MRI brain was reported normal. Intraocular pressure (IOP) and optical coherence tomography of the retinal nerve fibre layer (RNFL) were within normal limits. A tentative diagnosis of normal tension glaucoma was made. Over the next 5 years, IOP remained stable without treatment, serial visual fields noted repeatable bilateral superior depressions with normal RNFL. Referral to a glaucoma subspecialist and subsequently neuro-ophthalmologist prompted repeat MRIs, which demonstrated mild small vessel ischaemia. Standard visual evoked potentials (VEPs) were normal. Multifocal VEPs identified poor response across the entire visual field in both eyes. The combination of visual defects, unremarkable RNFL and reduced multifocal VEPs raised suspicion of bilateral inferior calcarine fissure change. Retrospective review of MRI’s in a multidisciplinary meeting confirmed extensive microvascular changes with bilateral inferior calcarine fissure ischaemia.


2020 ◽  
pp. bjophthalmol-2020-317034
Author(s):  
Meghal Gagrani ◽  
Jideofor Ndulue ◽  
David Anderson ◽  
Sachin Kedar ◽  
Vikas Gulati ◽  
...  

PurposeGlaucoma patients with peripheral vision loss have in the past subjectively described their field loss as ‘blurred’ or ‘no vision compromise’. We developed an iPad app for patients to self-characterise perception within areas of glaucomatous visual field loss.MethodsTwelve glaucoma patients with visual acuity ≥20/40 in each eye, stable and reliable Humphrey Visual Field (HVF) over 2 years were enrolled. An iPad app (held at 33 cm) allowed subjects to modify ‘blur’ or ‘dimness’ to match their perception of a 2×2 m wall-mounted poster at 1 m distance. Subjects fixated at the centre of the poster (spanning 45° of field from centre). The output was degree of blur/dim: normal, mild and severe noted on the iPad image at the 54 retinal loci tested by the HVF 24-2 and was compared to threshold sensitivity values at these loci. Monocular (Right eye (OD), left eye (OS)) HVF responses were used to calculate an integrated binocular (OU) visual field index (VFI). All three data sets were analysed separately.Results36 HVF and iPad responses from 12 subjects (mean age 71±8.2y) were analysed. The mean VFI was 77% OD, 76% OS, 83% OU. The most common iPad response reported was normal followed by blur. No subject reported dim response. The mean HVF sensitivity threshold was significantly associated with the iPad response at the corresponding retinal loci (For OD, OS and OU, respectively (dB): normal: 23, 25, 27; mild blur: 18, 16, 22; severe blur: 9, 9, 11). On receiver operative characteristic (ROC) curve analysis, the HVF retinal sensitivity cut-off at which subjects reported blur was 23.4 OD, 23 OS and 23.3 OU (dB).ConclusionsGlaucoma subjects self-pictorialised their field defects as blur; never dim or black. Our innovation allows translation of HVF data to quantitatively characterise visual perception in patients with glaucomatous field defects.


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