Effects of early postfiltration ocular hypotony on visual acuity, long-term intraocular pressure control, and posterior segment morphology.
OBJECTIVE
To determine whether hypotony after filtration surgery has any influence on visual acuity and intraocular pressure (IOP) lowering.


METHODS
We prospectively investigated 43 eyes of 43 patients undergoing trabeculectomy without the use of antimetabolites for 12 months.


RESULTS
The lowest postoperative IOP valued 4.9 +/- 3.6 mm Hg (range, 0-14 mm Hg). It correlated statistically significant with the IOP 6 weeks (P = 0.016), 6 months (P = 0.009), and 1 year after surgery (P = 0.027). Eyes with a deterioration of visual acuity 6 weeks after surgery had undergone a stronger postoperative hypotony (correlation with lowest postoperative IOP, P = 0.035). The mean period with an IOP less than 5 mm Hg was 3.5 +/- 8.0 days, and the mean period with an IOP less than 10 mm Hg lasted 45.4 +/- 68.8 days (range, 0-276 days). A hypotony score based on IOP and duration of hypotony was introduced. A correlation was detected between morphologic signs of hypotony, such as tiny retinal folds, at the 6-month follow-up and the duration of hypotony (P = 0.029) and hypotony score (P = 0.001).


CONCLUSIONS
Hypotony after filtration surgery may decrease visual acuity in the early postoperative period. Conversely, early postoperative hypotony correlated with better long term IOP control. There was no deleterious effect on visual acuity after 6 months.
Schwenn
O
O
Eye Hospital of the Johannes Gutenberg-Universität, Mainz, Germany.
Kersten
I
I
Dick
H B
HB
Müller
H
H
Pfeiffer
N
N
D000328:Adult; D015862:Choroid Diseases / Q000175:diagnosis / Q000209:etiology; D005654:Fundus Oculi; D005902:Glaucoma, Open-Angle / Q000601:surgery; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D015814:Ocular Hypotension / Q000209:etiology / Q000503:physiopathology*; D010211:Papilledema / Q000175:diagnosis / Q000209:etiology; D011446:Prospective Studies; D012164:Retinal Diseases / Q000175:diagnosis / Q000209:etiology; D014130:Trabeculectomy / Q000009:adverse effects*; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology