Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, USA.
Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA.
Am J Ophthalmol. 2019 Jun;202:126-132. doi: 10.1016/j.ajo.2019.02.014. Epub 2019 Feb 19.
Hyposecretion of aqueous humor has been postulated to adversely affect the health of the trabecular meshwork and outflow resistance. However, the effect of medications that reduce aqueous humor production on outflow facility in living human eyes is unclear. This study evaluated the effect of timolol, an aqueous humor flow suppressant, on outflow facility in healthy eyes.
Prospective, before-and-after study.
In a multicenter study, 113 healthy participants over 40 years of age were included. Intraocular pressure (IOP) was measured with the participant in the sitting position by using a pneumatonometer. The outflow facility was measured with the participant in the supine position by 2-minute pneumatonography. After participants self-administered drops of timolol 0.5% for 1 week, twice daily in each eye, both measurements were repeated.
Mean IOP decreased from 15.1 ± 3.0 mm Hg at baseline to 12.4 ± 2.4 mm Hg (P < 0.001) after 1 week of timolol use. Mean outflow facility decreased from 0.23 ± 0.08 μL/min/mm Hg at baseline to 0.18 ± 0.08 μL/min/mm Hg (P < 0.001) after timolol. The change in outflow facility was negatively correlated with baseline outflow facility (r = -0.51; P < 0.001).
Timolol reduces outflow facility in healthy human eyes, and this effect is greater in eyes with higher baseline outflow facility. This phenomenon may be related to reduced aqueous humor flow, but the precise mechanism remains to be determined.
有人推测房水分泌不足会对小梁网和流出阻力的健康产生不利影响。然而，减少房水生成的药物对活体人眼中流出阻力的影响尚不清楚。本研究评估了作为房水流动抑制剂的噻吗洛尔对健康眼中流出阻力的影响。
前瞻性、前后对照研究。
在一项多中心研究中，纳入了 113 名年龄在 40 岁以上的健康参与者。使用气动眼压计让参与者坐在座位上测量眼内压（IOP）。让参与者仰卧位，通过 2 分钟的气动眼压描记法测量流出阻力。参与者自行滴用噻吗洛尔 0.5%，每天两次，每只眼各滴用 1 周后，重复这两项测量。
平均 IOP 从基线时的 15.1 ± 3.0mmHg 降至滴用噻吗洛尔 1 周后的 12.4 ± 2.4mmHg（P < 0.001）。平均流出阻力从基线时的 0.23 ± 0.08μL/min/mm Hg 降至滴用噻吗洛尔后的 0.18 ± 0.08μL/min/mm Hg（P < 0.001）。流出阻力的变化与基线时的流出阻力呈负相关（r=-0.51；P < 0.001）。
噻吗洛尔降低了健康人眼中的流出阻力，而在基线时流出阻力较高的眼中，这种作用更大。这种现象可能与房水流动减少有关，但确切的机制仍有待确定。
