Planned Elevation of Intraocular Pressure With Temporary Occlusion of the Central Retinal Artery During Retinal Surgery

To the Editor.  —There are three occasions when the surgeon may deliberately elevate the intraocular pressure and close the central retinal artery (no pulsations): (1) scleral buckling without drainage, (2) elevation of the infusion bottle to tamponade intraocular hemorrhage, and (3) injection of gas into the vitreous (eg, pneumatic retinopexy¹).Animal experiments have shown that elevation of the intraocular pressure above 100 mm Hg for 60 minutes does not damage the electroretinographic function of the retina.^2,3 However, the electroretinogram is not very sensitive, and the a wave is particularly resistent to ischemia. Therefore, the functional studies on human eyes are more relevant.Bock et al⁴ studied nine human eyes with malignant melanoma, but with normal macular function, several days before enucleation. He evaluated visual acuity, perimetry, and dark adaptometry and then raised the intraocular pressure above 100 mm Hg for 60 minutes, closing the central retinal artery.