The standard 24-2 perimetry test is the workhorse of glaucoma assessment. It is also insufficient on its own when premium IOL implantation is being considered.
What the 10-2 detects that the 24-2 misses
The problem is mathematical. The 24-2 samples the central visual field with relatively widely-spaced points; the 10-2 samples the central 10 degrees with denser coverage. When both tests are performed in the same patient, the 10-2 detects abnormalities in nearly as many hemifields as the 24-2, including in eyes with normal 24-2 fields. The pattern of these defects is consistent with a model of macular damage that the 24-2 cannot adequately resolve.¹
The anatomical reason
The anatomical reason is the macula’s particular susceptibility in early glaucoma. Optical coherence tomography of the retinal nerve fibre layer and ganglion cell complex demonstrates that glaucomatous damage frequently involves the macular region early in the disease, with thinning concentrated inferiorly and corresponding visual field defects close to fixation in the upper field.² A 24-2 with full mean deviation does not exclude this damage.
For premium IOL candidacy, the threshold is straightforward. Published series of EDOF IOL outcomes in early glaucoma have used selection criteria that explicitly exclude fixation-threatening defects.³ The 10-2 is the test that confirms or refutes that criterion.
Patients are reassured by structured numbers. MD better than -3 dB sounds reassuring. It does not, by itself, exclude central involvement. A clean 10-2, not just a clean 24-2, should be part of the candidacy assessment whenever there is any suggestion that the macula may be involved.
References
- Traynis I, De Moraes CG, Raza AS, Liebmann JM, Ritch R, Hood DC. Prevalence and nature of early glaucomatous defects in the central 10° of the visual field. JAMA Ophthalmol. 2014;132(3):291-297.
- Hood DC, Raza AS, de Moraes CG, Liebmann JM, Ritch R. Glaucomatous damage of the macula. Prog Retin Eye Res. 2013;32:1-21.
- Kerr NM, Moshegov S, Lim S, Simos M. Visual outcomes, spectacle independence, and patient-reported satisfaction of the Vivity extended range of vision intraocular lens in patients with early glaucoma: an observational comparative study. Clin Ophthalmol. 2023;17:1515-1523.
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