Abstract
Purpose:
Millions of people worldwide are affected with glaucoma. No studies have been done to show if the normal lid anatomy affects the intraocular (IOP) pressure. Our hypothesis is that the apposition of normal lid against the eyeball and the process of blinking maybe facilitating the pressure-dependent flow of aqueous through the trabecular meshwork, similar to digital massage maneuver. We wanted to test this hypothesis in patients with ectropion who have successfully undergone surgery and comparing the post-operative to the pre-operative IOP's.
Methods:
This was a retrospective chart analysis. 32 patients were identified who successfully underwent tarsal strip procedure from 2010-2013. All surgeries were performed by the same surgeon. Patients with glaucoma or any other condition of the eye that could potentially affect the IOP were excluded. The average of all pre-operative IOP measurements were compared to the average of all postoperative IOP measurements, taken at least 1 month after the surgery.
Results:
Nine eyes in 7 patients were finally identified that met the inclusion criteria. An average of 5.57 IOP measurements were taken pre-operatively (range, 1-13). There was an average of 2.43 IOP measurements taken post-operatively (range, 1-8). Mean follow-up was 10.14 months (range 1-32 months). The average change of IOP in post-operative eyes was a reduction of 10.21% (range -37.50%- +12.5%). In patients who had surgery done in only one eye, the pre- and post- operative IOP change was compared between the operated eye and the non-operated eye. The average reduction of IOP was 15.20% (range, -34.47% to +12.30%).
Conclusions:
The present study shows that there was a reduction in IOP by about 10-15% by re-approximating the inferior lid to the eyeball. this supports our original hypothesis that normal position of the lower lid and the blink reflex maybe contributing to some extent in the lowering of IOP in a normal eye. It maybe interesting to see f this response is exaggerated in eyes with glaucoma. Limitations of this study were retrospective nature and small sample size. Although only one oculoplastic surgeon performed all procedures, the IOP's were measured by different operators at different times of the day. Future prospective studies with more number of normal eyes and in patients with glaucoma may validate this hypothesis.
Keywords: 526 eyelid •
568 intraocular pressure •
427 aqueous