Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2018 Jun;15(6):5065-5069.
doi: 10.3892/etm.2018.6051. Epub 2018 Apr 11.

Positive correlation between blood reflux in Schlemm's canal and the decrease of intraocular pressure after selective laser trabeculoplasty in primary open-angle glaucoma

Jie-Ling Gong  1 , Samer Abdo Al-Wesabi  1 , Yin Zhao  1 , Hong Zhang  1
Affiliations

Positive correlation between blood reflux in Schlemm's canal and the decrease of intraocular pressure after selective laser trabeculoplasty in primary open-angle glaucoma

Jie-Ling Gong et al. Exp Ther Med. 2018 Jun.

Abstract

The aim of the present study was to investigate the association between blood reflux in Schlemm's canal (SC) and the decrease of intraocular pressure (IOP) after selective laser trabeculoplasty (SLT) in primary open-angle glaucoma (POAG). To verify this, 35 eyes from 25 POAG patients were enrolled. All eyes underwent 360° whole-circle gonioscopy via a three-mirror lens, prior to undergoing 360° SLT. The four quadrants of the examined eye were individually compressed by the lens, and the presence of blood reflux in SC after removal of the pressure was recorded. Eyes with no blood reflux in any quadrant were assigned to the negative group, while the others were assigned to the positive group. Patients were evaluated at baseline, at 1 and 2 weeks, and at 1, 3 and 6 months after SLT. The results indicated that in the reflux-positive (21 eyes) and -negative (14 eyes) group, a significant IOP decrease was seen at 1 and 2 weeks, and at 1 and 3 months after SLT as compared with that pre-SLT IOP (P<0.01). In the negative group, the IOP at 6 months after SLT was not significantly different (P>0.05), while the positive group still exhibited a significant decrease in IOP compared with that at baseline (P<0.01). The positive group also presented with a greater decline in IOP at 1, 3 and 6 months compared with that in the negative group (P<0.05). A positive correlation between the number of quadrants with blood reflux in SC and the percentage decrease in IOP after SLT was identified in the positive group (P<0.05). In conclusion, blood reflux in SC was positively correlated with the decrease in IOP after SLT in POAG (Trialapproval number, K-2014-013).

Keywords: Schlemm's canal; blood reflux; intraocular pressure; primary open-angle glaucoma; selective laser trabeculoplasty.

PubMed Disclaimer

Figures

Figure 1.
Figure 1.
Gonioscopic view of the chamber angle with iris processes. (A) In the negative group, blood reflux in SC was absent after removal of the pressure from the lens at the viewed quadrant. (B) In the positive group, blood is observed in the SC removal of the pressure from the lens at the viewed quadrant. The two images were taken at the same quadrant from different eyes. ∆ indicates blood in the SC. SC, Schlemm's canal.
Figure 2.
Figure 2.
In the positive group, the number of quadrants with blood reflux was positively correlated with the decrease in IOP after SLT. This correlation was identified at (A) 3 months (P=0.037) and (B) 6 months (P=0.020) after the SLT. The abscissa refers to the numbers of the quadrants with blood reflux in Schlemm's canal. SLT, selective laser trabeculoplasty; IOP, intraocular pressure.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Quigley HA. Glaucoma. Lancet. 2011;377:1367–1377. doi: 10.1016/S0140-6736(10)61423-7. - DOI - PubMed
    1. Tamm ER, Fuchshofer R. What increases outflow resistance in primary open-angle glaucoma? Surv Ophthalmol. 2007;52(Suppl 2):S101–S104. doi: 10.1016/j.survophthal.2007.08.002. - DOI - PubMed
    1. Bill A, Svedbergh B. Scanning electron microscopic studies of the trabecular meshwork and the canal of Schlemm-an attempt to localize the main resistance to outflow of aqueous humor in man. Acta Ophthalmol (Copenh) 1972;50:295–320. doi: 10.1111/j.1755-3768.1972.tb05954.x. - DOI - PubMed
    1. Latina MA, Park C. Selective targeting of trabecular meshwork cells: In vitro studies of pulsed and CW laser interactions. Exp Eye Res. 1995;60:359–371. doi: 10.1016/S0014-4835(05)80093-4. - DOI - PubMed
    1. Johnson DH, Johnson M. How does nonpenetrating glaucoma surgery work? Aqueous outflow resistance and glaucoma surgery. J Glaucoma. 2001;10:55–67. doi: 10.1097/00061198-200102000-00011. - DOI - PubMed