24-2 Visual Fields Miss Central Defects Shown on 10-2 Tests in Glaucoma Suspects, Ocular Hypertensives, and Early Glaucoma

Abstract

Purpose To investigate the prevalence of visual field defects in glaucomatous eyes, glaucoma suspects, and ocular hypertensives with 24-2 and 10-2 visual fields. Design Prospective, cross-sectional study. Participants Patients with or suspected glaucoma. Testing 24-2 and 10-2 visual fields. Patients were classified into 3 groups based upon the presence of glaucomatous optic neuropathy (GON) and 24-2 visual field abnormalities: early glaucoma (GON and abnormal visual field, mean deviation >−6 dB), glaucoma suspects (GON and normal visual field), and ocular hypertensives (normal disc, normal visual field, and intraocular pressure >22 mmHg). For the classification of visual field abnormalities, 24-2 and 10-2 tests performed on the same visit were analyzed. Main outcome measure Comparison of the prevalence of abnormal 24-2 versus 10-2 visual field results based upon cluster criteria in each diagnostic group. Results 775 eyes (497 patients) were evaluated. 364 eyes had early glaucoma, 303 were glaucoma suspects, and 108 were ocular hypertensives. In the glaucoma group, 16 of the 26 (61.5%) eyes classified as normal based upon cluster criteria on 24-2 tests were classified as abnormal on 10-2 visual fields. In eyes with suspected glaucoma, 79 of the 200 (39.5%) eyes classified as normal on 24-2 were classified as abnormal on 10-2 visual fields. In ocular hypertensive eyes, 28 of the 79 (35.4%) eyes classified as normal on the 24-2 were abnormal on the 10-2. Patients of African descent were more likely to have an abnormal 10-2 result (67.3 vs. 56.8%, P=0.009). Conclusions Central visual field damage seen on 10-2 is often missed with 24-2 strategy in all groups. This finding has implications for the diagnosis of glaucoma and classification of severity.

Association of Macular Visual Field Measurements With Glaucoma Staging Systems

“…In recent years, this misconception has been challenged by investigators who used different methods to reach very similar conclusions. 7,9,10,[13][14][15]30 Another important reason is the more recent implementation of SD-OCT for glaucoma diagnosis and monitoring. High-resolution imaging of the macula has allowed the visualization of the RGCP layer, where glaucomatous damage occurs.…”

“…There is growing evidence that 24-2 SAP results can miss damage within the central 10°of the visual field that would otherwise be detected if one used a denser grid (2 × 2°), such as that tested with 10-2 SAP. [7][8][9][10][11][12][13][14][15] Furthermore, studies using spectral-domain optical coherence tomography (SD-OCT) have shown that macular damage in early glaucoma is much more common than previously thought and is often present in eyes with 24-2 mean deviation (MD) better (ie, closer to 0) than −6 dB. [16][17][18][19][20] Because of their importance in clinical and research settings, and given their substantial association with measures of vision-related quality of life, 21,22 24-2 (or 30-2) SAP metrics have traditionally been used to stage glaucoma severity.…”

Recent Developments in Glaucoma

“…However, in a recent study in the US 22 in patients with suspected glaucoma, 79 of the 200 eyes (39.5%) classified as normal on the 24-2 test were classified as abnormal on 10-2 visual fields. In ocular hypertensive eyes, 28 of the 79 eyes (35.4%) classified as normal on the 24-2 test were classified as abnormal on the 10-2 test.…”

Neuroprotection in Glaucoma: Towards Clinical Trials and Precision Medicine

“…76 It has also been suggested that the 10-2 visual field may be a more appropriate outcome measure as the 24-2 field can underestimate the degree of damage at the macular region involved in glaucomatous optic neuropathy. 77 The 10-2 visual field has also been shown to correlate with quality of life outcome measures 78 and may reduce the time required to detect glaucomatous progression. 79 Wu et al also indicates that lengthy and large trials are not essential, suggesting that the sample size required to assess the effect of any neuroprotective intervention depends on the baseline rate of progression, study duration, and quantification and outcome parameter.…”