Swelling and loss of photoreceptors in chronic human and experimental glaucomas.
OBJECTIVE
To determine whether outer retinal changes occur in chronic, presumed primary open-angle glaucoma (POAG).


METHODS
The outer retinas from 128 human eyes with a diagnosis of chronic glaucoma (presumably POAG in most cases) and 90 control eyes were examined histologically by 3 masked observers for photoreceptor swelling and loss. Retinas from 9 rhesus monkeys with glaucoma induced experimentally by laser trabecular destruction were compared with 7 fellow (control) eyes. The mean pressure elevations in the eyes with laser trabecular destruction ranged from 26.6 to 53.6 mm Hg with durations varying from 7 to 33 weeks.


RESULTS
Swelling of the red- and green-sensitive cones was observed in a statistically significantly greater proportion of human eyes with presumed POAG compared with the control eyes. Patchy loss of red/green cones and rods was also found in some of the glaucomatous retinas. In a subset of the human eyes with end-stage disease, cone swelling was a variable finding. Although no photoreceptor loss was found in the 9 monkey eyes with experimental glaucoma, 8 had swelling of their red/green cones that was remarkably similar to that seen in the human eyes. Swelling was not present in any of the control monkey eyes.


CONCLUSIONS
The photoreceptors are affected by chronically elevated intraocular pressure.


CONCLUSIONS
These findings may explain some of the abnormalities of color vision and the electrophysiological effects that have been observed in patients with POAG.
Nork
T M
TM
Department of Ophthalmology and Visual Sciences, University of Wisconsin Medical School, Madison 53792-3220, USA. tmnork@facstaff.wisc.edu
Ver Hoeve
J N
JN
Poulsen
G L
GL
Nickells
R W
RW
Davis
M D
MD
Weber
A J
AJ
Vaegan
Sarks
S H
SH
Lemley
H L
HL
Millecchia
L L
LL
D000368:Aged; D000818:Animals; D016923:Cell Death; D002908:Chronic Disease; D003117:Color Vision Defects / Q000209:etiology; D004195:Disease Models, Animal; D004487:Edema / Q000209:etiology* / Q000473:pathology; D005260:Female; D005902:Glaucoma, Open-Angle / Q000150:complications*; D006801:Humans; D007429:Intraocular Pressure; D008253:Macaca mulatta; D008297:Male; D020419:Photoreceptor Cells, Vertebrate / Q000473:pathology*; D012164:Retinal Diseases / Q000209:etiology* / Q000473:pathology; D012165:Retinal Ganglion Cells / Q000473:pathology