Table 1.

Magnitude of intraocular pressure reduction in nonglaucomatous eyes in different studies.

Study (year)	Amount of IOP lowering (mmHg)	Length of follow-up
Matsumura et al. (1996)	1.5	3 years
Suzuki et al. (1997)	No change from preop. level	10 years
Jahn (1997)	2	5 years
Tong and Miller (1998)	2	6–8 months
Schwenn et al. (2001)	0.6 (scleral tunnel), 1.5 (clear cornea)	5 months
Pohjalainen et al. (2001)	3.5	1–2.7 years
Shingleton et al. (2006)	1.5	3 years
Kim et al. (2009)	1.5	1 month