The Acute Morphologic Changes That Occur at the Optic Nerve Head Induced by Medical Reduction of Intraocular Pressure

Abstract

In the present study, it was shown that acute and statistically significant alterations in optic disc morphology occur when IOP is lowered medically with a combination of topical apraclonidine and systemic acetazolamide. The technique, therefore, may be useful to further investigate subgroups of glaucomatous eyes and test etiologic hypotheses.

Laminar Displacement and Prelaminar Tissue Thickness Change after Glaucoma Surgery Imaged with Optical Coherence Tomography

“…18,19 Because these studies used CSLT in which the ALS cannot be visualized, the source of ONH surface changes cannot be precisely elucidated. Backward bowing of the lamina has long been recognized as a characteristic feature of glaucomatous optic neuropathy.…”

“…10,11 Several studies have examined ONH surface changes with confocal scanning laser tomography (CSLT) after surgical [12][13][14][15][16][17] or medical 18,19 reduction of IOP. However, because CSLT is able to image only ONH surface changes, none of these earlier studies were able to evaluate the contribution of deep ONH structures resulting in the increase of neuroretinal rim area and decrease of optic disc cupping after IOP reduction.…”

Factors associated with topographic changes of the optic nerve head induced by acute intraocular pressure reduction in glaucoma patients

“…On the other hand, Wells et al 13 correlated higher CH values (but not CCT) with greater changes in ONH topography after IOP increase. In this study, we analyzed cupping reversal (IOP reduction), which was the methodology used in the majority of previous studies, [7][8][9][10][11][12] in a study population composed of POAG patients without intraocular surgery. Wells et al 13 evaluated cupping distension (increasing IOP to an average of 64 mm Hg) in different types of glaucoma, some with intraocular surgery and with a lower mean age than our group.…”

“…The reduction in IOP was associated with an increase in the neural rim area and a decrease in the cup size, probably due to anterior shifting of the LC. [7][8][9][10][11][12] The inverse mechanism was observed after IOP elevation. 13 Susceptibility to glaucomatous damage varies among patients and seems to be related to several individual ocular and systemic characteristics.…”

“…13 Susceptibility to glaucomatous damage varies among patients and seems to be related to several individual ocular and systemic characteristics. Although some factors such as age 1,[14][15][16] and central corneal thickness (CCT) are better established, 1,14,16 others such as corneal hysteresis (CH) 17 and diabetes mellitus (DM) 11,[18][19][20][21] remain controversial.…”