Glaucoma

9 Glaucoma




Anatomy/physiology




Ciliary body (CB)


6-mm-wide structure located between the scleral spur anteriorly and the ora serrata posteriorly; composed of the pars plicata (anterior 2 mm with ciliary processes) and the pars plana (posterior 4 mm, flat)


Pars plicata consists of






Functions












Angle Structures


Visible only by gonioscopy because of total internal reflection at the air/cornea interface (Figure 9-1)










Angle Abnormalities










Testing





Tonometry


IOP measurement can be performed with a variety of devices (tonometers)






Gonioscopy






Visual Fields


Perimetry measures the ‘island of vision’ or topographic representation of differential light sensitivity. Peak = fovea; depression = blind spot; extent = 60° nasally, 60° superiorly, 70–75° inferiorly, and 100–110° temporally


Central field tests points only within a 30° radius of fixation





Humphrey (static)











Optic Nerve Head (ONH) Analyzers


Various digital and video cameras that capture ONH image; computer then calculates cup area in an attempt to objectively quantify ONH appearance (Table 9-1)








Pathology




Jun 4, 2016 | Posted by in OPHTHALMOLOGY | Comments Off on Glaucoma
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