Endothelin-1 increase in aqueous humour caused by frequency-doubled Nd:YAG laser trabeculoplasty in rabbits.
OBJECTIVE
To study the effect of Nd:YAG laser trabeculoplasty (LT) on endothelin-1 (ET-1) concentration of aqueous humour and intraocular pressure (IOP) in rabbits.


METHODS
One eye of each of 18 pigmented rabbits was subjected to 360 degrees LT with a frequency-doubled Nd:YAG laser (532 nm), and IOP was measured with a Tono-Pen tonometer before treatment. Post-LT IOP measurements followed by aqueous humour aspiration were performed under general anaesthesia at 3 and 12 h and 1, 3 and 7 days after the treatment. The concentration of ET-1 in aqueous humour was measured by means of a radioimmunoassay.


RESULTS
In the eyes that had undergone LT, the concentrations of ET-1 in the aqueous humour were significantly increased at 3, 12 and 24 h after the treatment compared with the contralateral eyes. ET-1 concentrations at 3 and 7 days after LT, however, did not differ significantly from the corresponding contralateral control values. IOP increased following the treatment at 3 and 12 h. IOP values were significantly lower in the treated eyes at 1, 3 and 7 days after the treatment than in the control eyes.


CONCLUSIONS
The results show that LT in rabbits was followed by an immediate and short-term increase in aqueous humour ET-1 that might be caused by leakage from uveal tissue. This may be responsible for the release of prostaglandins causing the IOP increase and inflammatory complications of LT.
Guzey
M
M
Department of Ophthalmology, Harran University, School of Medicine, Sanliurfa, Turkey. guzey@turk.net
Vural
H
H
Satici
A
A
D000818:Animals; D001082:Aqueous Humor / Q000737:chemistry / Q000378:metabolism*; D019332:Endothelin-1 / Q000032:analysis / Q000378:metabolism*; D007429:Intraocular Pressure; D053685:Laser Therapy; D011817:Rabbits; D011863:Radioimmunoassay / Q000379:methods; D013997:Time Factors; D014130:Trabeculectomy
D019332:Endothelin-1