Pattern electroretinogram association with spectral domain-OCT structural measurements in glaucoma

Abstract

Purpose To describe the association between pattern electroretinogram (PERG) amplitude and spectral domain-optical coherence tomography (SD-OCT) macular thickness, retinal nerve fibre layer (RNFL) thickness and optic disc topography measurements. Subjects and methods Both eyes (n ¼ 132) of 66 glaucoma patients (mean age ¼ 67.9 years) enroled in the University of California, San Diego, CA, USA, Diagnostic Innovations in Glaucoma Study (DIGS) were included. Eyes were tested with PERG (Glaid PERGLA, Lace Elettronica, Pisa, Italy), RTVue SD-OCT (Optovue Inc., Fremont, CA, USA) GCC, and NHM4 protocols on the same day. Of the 66 enroled patients, 43 had glaucoma defined by repeated abnormal standard automated perimetry (SAP) results in at least one eye and 23 were glaucoma suspects defined by a glaucomatous-appearing optic disc by physicians' examination in at least one eye and normal SAP results in both eyes. Associations (R 2 ) were determined between PERG amplitude (lV) and SD-OCT macular ganglion cell complex (GCC) thickness (lm), macular thickness (lm), macular outer retinal thickness (macular thickness minus GCC thickness) (lm), RNFL thickness (lm), neuroretinal rim area (mm 2 ), and rim volume (mm 3 ). Results PERG amplitude was significantly associated with GCC thickness (R 2 ¼ 0.179, Po0.001), RNFL thickness (R 2 ¼ 0.174, Po0.001), and macular thickness (R 2 ¼ 0.095, Po0.001). R 2 associations with other parameters were not significant (all P40.624). Significant associations remained for GCC and average RNFL thickness when age and intraocular pressure at the time of testing were included in multivariate models (both Pr0.030). Conclusions PERG amplitude is significantly (but weakly) associated with macular GCC thickness, RNFL thickness, and macular thickness. The lack of association between PERG amplitude and macular outer retinal thickness supports previous results, possibly suggesting that that the PERG is driven primarily by retinal ganglion cell (inner retinal) responses.

Progressive Loss of Retinal Ganglion Cell Function Precedes Structural Loss by Several Years in Glaucoma Suspects

“…In recent publications, PERG has been shown to be reduced in glaucoma suspects, and ocular hypertensive and glaucoma patients. [27][28][29] Many attempts have been made to correlate the structure and function of the optic nerve in glaucoma. [30][31][32][33][34][35][36] Structural measurements have been made in the past measuring the size of the optic nerve, and the thickness of the optic nerve and RNFL.…”

Comment on the role of 3T diffusion tensor imaging in glaucoma

“…2 and 3). As for criterion 2, the absence of other disease that would explain the visual field abnormality was obviously a fundamental criterion for exclusion during enrolment as stated in the Methods section.…”

Eletrorretinograma de padrão reverso macular e multifocal e tomografia de coerência óptica em olhos suspeitos de glaucoma e glaucomatosos com perda de hemicampo

“…É importante notar que enquanto a maior parte dos estudos de PERG em pacientes com SG ou glaucoma estabelecido encontraram uma redução na amplitude das respostas do PERG (13,82,92,94,98) , em nossa investigação nenhum dos parâmetros de amplitude do PERG e do PERGmf estava anormal nos olhos com SG. Uma possível explicação para esta ausência de anormalidade nas medidas de amplitude nos olhos com SG é o fato de que a amplitude de resposta do PERG pode ter sido reestabelecida após redução farmacológica da PIO, conforme sugerido por estudos prévios (99,100) .…”

“…Por outro lado, no grupo com GH, a estimulação do PERG em modo estacionário resultou em medidas de amplitude significativamente reduzidas, assim como observado por estudos prévios em pacientes com glaucoma estabelecido (13,82,92,94,98) . (11,98,105,106) .…”

“…Ventura e Porciatti (116) propuseram que diferentes tempos de início de resposta de CGR magnocelulares (M) e parvocelulares (P) poderiam explicar o encurtamento da latência em diferentes condições de estímulo já que um dano seletivo de um subgrupo de CGR poderia ocorrer no glaucoma precoce. Na doença avançada, por outro lado, a latência prolongada pode ser devido a um dano mais severo de uma maior parcela das CGR, conforme evidenciado no tempo de pico prolongado do (13,94,117) . Uma forte e significante relação também foi observada entre a fase do modo estacionário e a SM da estratégia 10-2 e a SMC da estratégia 24-2 (Tabela 5).…”