Fixation Stability and Macular Light Sensitivity in Patients with Diabetic Maculopathy: A Microperimetric Study with a Scanning Laser Ophthalmoscope

Abstract

Background: In patients with diabetic maculopathy, evaluation of visual acuity alone may not represent central retinal function sufficiently. Despite good visual acuity, patients may suffer from visual disturbances like waviness, relative scotoma, loss of fixation and decrease of contrast sensitivity. The aim of the study was to assess localized light sensitivity in the central visual field and to determine fixation stability in patients with diabetic maculopathy with moderate visual loss in comparison to healthy controls. Methods: Twenty-seven patients (mean age: 54 ± 15; range 17–81 years) with diabetic maculopathy and 61 controls (mean age: 45 ± 22; range 18–85 years) were included in the study. Light sensitivity was quantified by presenting stimuli with different light intensity with simultaneous real-time monitoring of the retina (intensity: 0–27.9 dB; size: Goldmann III, wavelength: 633 nm). Eye movements were controlled by semiautomatic fundus tracking. Fixation stability was quantified by measuring the area within 75% of all points of fixation. Results: Fixation stability was significantly decreased in diabetic patients in comparison to controls (43 ± 22 vs. 31 ± 16 arc min, p < 0.01). There was a significant difference in macular light sensitivity in diabetic patients compared to controls (19.6 ± 0.5 dB), both in mean difference (15.6 ± 1.4 dB) and if affected with macular edema (16.1 ± 4.5 dB), hard exudates (13.3 ± 6.7 dB), nonperfusion areas (10.3 ± 7.9 dB) and laser burns (3.0 ± 6.1 dB). Temporal parts of the macula were more affected than other parts. No correlation was found between visual acuity and foveal light sensitivity and foveal fixation, respectively. Conclusion: Macular light sensitivity decreased progressively with the kind and severity of retinal alteration independent of visual acuity. The assessment of macular light sensitivity and stability of fixation with automatic threshold microperimetry may help to identify patients with diabetic maculopathy and could improve the management of diabetic maculopathy.

Longitudinal comparison of visual acuity as measured by the ETDRS chart and by the potential acuity meter in eyes with macular edema, and its relationship with retinal thickness and sensitivity

“…Such an observation was confirmed by previous studies of eyes with DME and UME. [18][19][20] Our findings were in contrast with some of the other reports. 15,21 Roesel et al 21 showed a correlation between retinal sensitivity measured with the MP1 (Nidek Technologies, Padova, Italy) and BCVA measured by the ETDRS chart in eyes with UME.…”

“…[12][13][14] Recently, microperimetry has added in-depth quantification of the function of the macula and has provided detailed information about the degree and pattern of retinal alteration in the course of edema. 1,2,15,18,19 The integrated automated fundus perimetry/tomography and SD-OCT module of the Spectral OCT/SLO system has allowed an in-depth and more accurate evaluation of both retinal anatomy and corresponding function, with novel findings about their relationship as well as with associated factors. In our current study, we have measured the retinal thickness and sensitivity using the Spectral OCT/SLO device, which is an automatic, simultaneous fundus perimetry/ tomography system, with a microperimetric circular pattern to cover the central 1 mm of the fixation center.…”

“…In previous studies, after adjustment for other factors such as retinal thickness, there has been no association between BCVA measured with the ETDRS chart and retinal sensitivity in eyes with DME and in those with UME. [18][19][20] Roesel et al 21 detected a significant negative correlation between retinal sensitivity and the logarithm of the minimum angle of resolution (LogMAR) values in eyes with UME.…”

Diabetik Makula Ödeminde MP-1 Mikroperimetri ile Fiksasyon Stabilitesi ve Makuler Duyarlılığın Değerlendirilmesi

“…[6][7][8][9] In our study, consistent with previous studies, a significant decrease in mean light sensitivity was also found. Retinal sensitivity and stability of fixation in CSME were reported to be reduced compared with normal values.…”

“…This decrease is mostly due to a localized loss of light sensitivity in areas with severe tissue alteration and to a lesser extent due to diffuse loss of light sensitivity. 9 Fixation characteristic are critical for many visual tasks like reading. Variations of size, shape, and intensity of scotoma greatly influence visual performance.…”