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Functional and morphological alterations in a glaucoma model of acute ocular hypertension

2020; Elsevier BV; Linguagem: Inglês

10.1016/bs.pbr.2020.07.003

1875-7855

Alejandro Gallego‐Ortega, María Norte‐Muñoz, Juan Antonio Miralles de Imperial‐Ollero, José Manuel Bernal-Garro, Francisco J. Valiente‐Soriano, Pedro de la Villa, Marcelino Avilés‐Trigueros, María Paz Villegas‐Pérez, Manuel Vidal‐Sanz,

Retinal Development and Disorders

To study short and long-term effects of acute ocular hypertension (AOHT) on inner and outer retinal layers, in adult Sprague-Dawley rats AOHT (87 mmHg) was induced for 90 min and the retinas were examined longitudinally in vivo with electroretinogram (ERG) recordings and optical coherent tomography (OCT) from 1 to 90 days (d). Ex vivo, the retinas were analyzed for rod (RBC) and cone (CBC) bipolar cells, with antibodies against protein kinase Cα and recoverin, respectively in cross sections, and for cones, horizontal (HZ) and ganglion (RGC) cells with antibodies against arrestin, calbindin and Brn3a, respectively in wholemounts. The inner retina thinned progressively up to 7 d with no further changes, while the external retina had a normal thickness until 30 d, with a 20% thinning between 30 and 90 d. Functionally, the a-wave showed an initial reduction by 24 h and a further reduction from 30 to 90 d. All other main ERG waves were significantly reduced by 1 d without significant recovery by 90 d. Radial sections showed a normal population of RBCs but their terminals were reduced. The CBCs showed a progressive decrease with a loss of 56% by 30 d. In wholemount retinas, RGCs diminished to 40% by 3 d and to 16% by 30 d without further loss. Cones diminished to 58% and 35% by 3 and 7 d, respectively and further decreased between 30 and 90 d. HZs showed normal values throughout the study. In conclusion, AOHT affects both the inner and outer retina, with a more pronounced degeneration of the cone than the rod pathway.