Psychophysical Measurements of Luminance Contrast Sensitivity and Color Discrimination with Transparent and Blue-Light Filter Intraocular Lenses.

INTRODUCTION: The purpose of this study was to measure luminance contrast sensitivity and color vision thresholdfs in normal subjects using a blue light filter lens and transparent intraocular lens material. METHODS: Monocular luminance grating contrast sensitivity was measured with Psycho for Windows (version 2.36; Cambridge Research Systems) at 3.0, 6.0, 12.0, 20.0, and 30.0 cycles per degree of visual angle (cpd) in 15 normal subjects (eight female), with a mean age of 21.6 years (SD = 3.8 years). Chromatic discrimination was assessed with the Cambridge colour test (CCT) along the protan, deutan, and tritan color confusion axes. Both tests were performed in a darkened room under two situations: with a transparent lens and with blue light filter lens. Subjective impressions were taken by subjects regarding their visual experience under both conditions. RESULTS: No difference was found between the luminance contrast sensitivity measured with transparent and blue light filter. However, 13/15 (87%) of the subjects reported more comfortable vision with the blue filter. In the color vision test, tritan thresholds were significantly higher for the blue filter compared with the transparent filter (p = 0.003). For protan and deutan thresholds no differences were found. CONCLUSION: Blue-yellow color vision is impaired with the blue light filter, and no impairment occurs with the transparent filter. No significant differences in thresholds were found in the luminance contrast sensitivity comparing the blue light and transparent filters. The impact of short wavelength light filtering on intrinsically photosensitive retinal ganglion cells is also discussed.

Spectral-domain optical coherence tomography for early glaucoma assessment: analysis of macular ganglion cell complex versus peripapillary retinal nerve fiber layer.

OBJECTIVE: We sought to compare the glaucoma discrimination ability of macular inner retinal layer (MIRL) thickness with that of conventional peripapillary retinal nerve fiber layer (pRNFL) thickness as measured by spectral-domain optical coherence tomography (SD-OCT) in patients with early glaucoma. DESIGN: Cross-sectional study. PARTICIPANTS: We studied 67 patients with early glaucoma (visual field mean deviation index ≥-6 dB), and 56 healthy subjects were prospectively enrolled. METHODS: All patients underwent MIRL thickness measurement (ganglion cell complex [GCC] scan) and pRNFL thickness measurement (3.45 mm scan) by SD-OCT. Whenever both eyes were eligible, one was randomly selected. Receiver operating characteristic curves and sensitivities at fixed specificities were generated for different parameters. The areas under the receiver operating characteristic curves (AUCs) of each parameter were compared. RESULTS: The average mean deviation for the glaucomatous eyes was -2.5 ± 1.6 dB. The AUCs for average (0.815); superior (0.807); and inferior (0.788) MIRL thicknesses were not significantly different (p ≥ 0.18). The AUCs for average (0.735); superior (0.728); and inferior (0.697) pRNFL thicknesses were also similar (p ≥ 0.15). Average MIRL thickness had a significantly larger AUC compared to average pRNFL thickness analysis (0.815 vs 0.735; p = 0.03). Sensitivities at 80% specificity for average MIRL and pRNFL thicknesses were 66.7% (cutoff, 89.9 µm) and 62.9% (cutoff, 111.8 µm), respectively. CONCLUSIONS: The GCC scan showed a similar or even a slightly better ability to discriminate between healthy and early glaucomatous eyes compared to the pRNFL scan. Different from previous analyses considering total macular thickness, the GCC macular scan seems to be a useful tool for identification of early structural damage in patients with glaucoma.

Influence of blue light spectrum filter on short-wavelength and standard automated perimetries.

PURPOSE: To evaluate the influence of a blue light spectrum filter (BLSF), similar in light spectrum transmittance to the intraocular lens Acrysof Natural, on standard automated perimetry (SAP) and short-wavelength automated perimetry (SWAP). METHODS: Twenty young individuals (< 30 y.o.), without any systemic or ocular alterations (twenty eyes) underwent a random sequence of four Humphrey visual field tests: standard automated perimetry (SAP) and short-wavelength automated perimetry (SWAP) with and without a blue light spectrum filter. All patients had intraocular pressure lower than 21 mmHg, normal fundus biomicroscopy, and no crystalline lens opacity. Foveal threshold (FT), mean deviation (MD), and pattern standard deviation (PSD) indexes obtained from the visual field tests and the difference caused by eccentricity in short-wavelength automated perimetry examinations were analyzed using paired t test. Interindividual variability (standard deviation) was calculated using Pitman's test for correlated samples. RESULTS: Statistically significant reductions in the mean deviation (p < 0.001) and in the foveal threshold (p < 0.001) measured by short-wavelength automated perimetry with the use of the blue light spectrum filter in comparison to short-wavelength automated perimetry without the use of the blue light spectrum filter were observed, but not in standard automated perimetry exams. No other parameters showed statistically significant differences in the short-wavelength automated perimetry and standard automated perimetry tests. Interindividual standard deviation of the test points in the short-wavelength automated perimetry exams increased with eccentricity both with and without the use of the blue light spectrum filter, as sensitivity for inferior and superior hemifields (inferior hemifield minus superior hemifield), but no statistically significant difference in the variability when comparing the use or not of the blue light spectrum filter was noted. When comparing only the four most inferior points and the four most superior points, the inferior-superior difference increases in both situations - without and with the use of the blue light spectrum filter. The difference between without and with the use of the blue light spectrum filter was not statistically significant. CONCLUSION: Statistically significant reductions in mean deviation and foveal threshold in the short-wavelength automated perimetry with the use of the blue light spectrum filter were observed, but not in standard automated perimetry examinations. Additional studies are necessary to determine the influence of intraocular lenses with short-wavelength light filter after cataract extraction on short-wavelength automated perimetry.

Influence of blue light spectrum filter on short-wavelength and standard automated perimetries / Influência de filtro para o espectro azul da luz na perimetria computadorizada branco-branco e azul-amarelo

PURPOSE: To evaluate the influence of a blue light spectrum filter (BLSF), similar in light spectrum transmittance to the intraocular lens Acrysof NaturalTM, on standard automated perimetry (SAP) and short-wavelength automated perimetry (SWAP). METHODS: Twenty young individuals (<30 y.o.), without any systemic or ocular alterations (twenty eyes) underwent a random sequence of four Humphrey visual field tests: standard automated perimetry (SAP) and short-wavelength automated perimetry (SWAP) with and without a blue light spectrum filter. All patients had intraocular pressure lower than 21 mmHg, normal fundus biomicroscopy, and no crystalline lens opacity. Foveal threshold (FT), mean deviation (MD), and pattern standard deviation (PSD) indexes obtained from the visual field tests and the difference caused by eccentricity in short-wavelength automated perimetry examinations were analyzed using paired t test. Interindividual variability (standard deviation) was calculated using Pitman's test for correlated samples. RESULTS: Statistically significant reductions in the mean deviation (p<0.001) and in the foveal threshold (p<0.001) measured by short-wavelength automated perimetry with the use of the blue light spectrum filter in comparison to short-wavelength automated perimetry without the use of the blue light spectrum filter were observed, but not in standard automated perimetry exams. No other parameters showed statistically significant differences in the short-wavelength automated perimetry and standard automated perimetry tests. Interindividual standard deviation of the test points in the short-wavelength automated perimetry exams increased with eccentricity both with and without the use of the blue light spectrum filter, as sensitivity for inferior and superior hemifields (inferior hemifield minus superior hemifield), but no statistically significant difference in the variability when comparing the use or not of the blue light spectrum filter was noted. When comparing...

OBJETIVO: Avaliar a influência de um filtro para o espectro azul da luz, semelhante à lente intra-ocular Acrysof Natural®, nos exames de perimetria automatizada padrão (branco-no-branco) e de comprimento de onda curto (azul-no-amarelo). MÉTODOS: Vinte pacientes jovens sem alterações oculares (20 olhos) realizaram seqüência de 4 exames de campo visual: perimetria automatizada padrão e azul-no-amarelo com e sem o filtro para o espectro azul da luz. Os índices de limiar foveal (FT), desvio médio (MD) e desvio-padrão (PSD) obtidos em todos os exames e a diferença causada pela excentricidade nos exames de perimetria automatizada azul-no-amarelo foram analisados. Variabilidade interindivíduos (desvio-padrão dos pontos testados) foi calculada. RESULTADOS: Observou-se redução estatisticamente significante no desvio médio (p<0.001) e no limiar foveal (p<0.001) medidos pela perimetria automatizada azul-no-amarelo com o uso do filtro para o espectro azul da luz comparado quando realizado sem o filtro. Nenhum outro índice avaliado apresentou diferença estatisticamente significante nos exames de perimetria automatizada padrão ou azul-no-amarelo. Foi notado aumento da variabilidade interindivíduos com a excentricidade nos exames de perimetria automatizada azul-no-amarelo com e sem o uso do filtro para o espectro azul da luz, assim como a diferença de sensibilidade entre os hemisférios inferior e superior (hemisfério inferior menos superior), mas não houve diferença estatisticamente significante quando comparados os exames com e sem o uso do filtro. Quando foram comparados os 4 pontos mais inferiores e os 4 pontos mais superiores, a diferença inferior-superior aumentou com e sem o uso do filtro para o espectro azul da luz. CONCLUSÃO: Observou-se redução estatisticamente significante no desvio médio e limiar foveal nos exames de perimetria automatizada azul-no-amarelo com o uso do filtro para o espectro azul da luz, mas não nos exames de perimetria automatizada padrão.