Quantification of the effect of different levels of IOP in the astroglia of the rat retina ipsilateral and contralateral to experimental glaucoma.
OBJECTIVE
To analyze the effects of different levels of intraocular pressure (IOP) in the macroglia in ocular hypertension (OHT) and contralateral eyes at 3 weeks after laser photocoagulation and compare these with effects in age-matched control rats.


METHODS
Adult Sprague-Dawley rats were divided into an age-matched control (naive) group and an OHT group. Retinas were processed as whole mounts and immunostained with GFAP for analysis of the retinal macroglia.


RESULTS
The area of the retina occupied by astrocytes (AROA) was quantified. GFAP immunostaining showed common features in ipsilateral and contralateral eyes. First, although the astrocyte network maintained a star-shaped morphology, these cells had fewer secondary processes and thinner cell bodies and primary processes than did naive cells. Second, Müller cells appeared as punctate GFAP+ structures among astrocytes. Third, there was a significant reduction of the AROA in ipsilateral and contralateral eyes compared with naive eyes. Ipsilateral eyes had significantly less AROA than did contralateral eyes. The decrease was greater for OHT eyes with higher IOP levels.


CONCLUSIONS
OHT induces changes in the macroglia of contralateral eyes; thus, these fellow eyes should not be used as control. In eyes with OHT, there is a close relationship between IOP values and decreased AROA.
Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense, Madrid, Spain. ramirezs@med.ucm.es
Ana I
AI
Ramírez
Juan J
JJ
Salazar
Rosa
R
de Hoz
Blanca
B
Rojas
Beatriz I
BI
Gallego
Manuel
M
Salinas-Navarro
Luis
L
Alarcón-Martínez
Arturo
A
Ortín-Martínez
Marcelino
M
Avilés-Trigueros
Manuel
M
Vidal-Sanz
Alberto
A
Triviño
Jose M
JM
Ramírez
D000818:Animals; D001253:Astrocytes / Q000378:metabolism / Q000473:pathology*; D002452:Cell Count; D004195:Disease Models, Animal; D005260:Female; D007839:Functional Laterality; D005901:Glaucoma / Q000378:metabolism / Q000473:pathology*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007124:Immunoenzyme Techniques; D007429:Intraocular Pressure / Q000502:physiology*; D009798:Ocular Hypertension / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012165:Retinal Ganglion Cells / Q000378:metabolism / Q000473:pathology*; D014065:Tonometry, Ocular
D005904:Glial Fibrillary Acidic Protein