Anterior Corneal Folds Correlate With Low Intraocular Pressure and May Serve as a Marker for Ocular Hypotony

Abstract

Purpose: Subtle folds can be seen in the anterior cornea in eyes with hypotony using fluorescein and blue light. We aim to assess their extent and grade with respect to the level of intraocular pressure (IOP). Patients and Methods: Patients who presented to the department of ophthalmology at Rambam Health Care Campus with IOP<10 mm Hg during the period between July 2016 and June 2017. Corneal folds were evaluated after instilling an anesthetic drop and fluorescein staining. Outcome measures included: IOP, presence of anterior corneal folds, and the percentage of corneal surface containing folds. Results: Overall, 100 eyes of 100 patients were included. The mean age±SD was 63.6±16.7 years (range, 19 to 96 y); 56% (n=56) were of male sex. Mean IOP was 5.3±2.7 mm Hg (range, 0 to 9 mm Hg). Subjects with and without anterior corneal folds were of similar age (P=0.25) and sex (P=0.69). Those with anterior corneal folds had a significantly lower IOP than the control group (4.0±2.4 vs. 7.4±1.7; P<0.001). Eyes with IOP of 0 to 2, 3 to 4, 5 to 6, 7 to 9 mm Hg demonstrated anterior corneal folds in 95%, 91%, 67%, and 18.4%, respectively. At an IOP≤5 mm Hg cut-off, the sensitivity and specificity of corneal folds as a predictor of hypotony was 89.8% and 70.6%, respectively. A significant inverse correlation between the relative area of the cornea covered by folds and the IOP was found (r=−0.7; P<0.001). Conclusions: Folds observed in the anterior corneal surface appear to be a robust sign of severe hypotony.

Risk Factors for Corneal Striae in Eyes After Glaucoma Surgery

“…Although corneal striae are a common clinical finding in hypotony, the only known association thus far has been low IOP 4. Our study adds to the body of knowledge by finding significant associations between striae and other measurements of the eye.…”

“…Although corneal striae are a common clinical finding in hypotony, the only known association thus far has been low IOP. 4 Our study adds to the body of knowledge by finding significant associations between striae and other measurements of the eye. In addition to low IOP, we show that striae are associated with a steeper cornea, more induced astigmatism, a higher postoperative CH, HM, shortened AL after surgery, longer duration of MMC, and lack of topical medication use.…”

“…[1][2][3] Vertical anterior corneal striae (ACS) are a frequent clinical observation in eyes with surgically induced hypotony and their presence indicate a 70% specificity of intraocular pressure (IOP) ≤ 5 mm Hg. 4 However, it is not known if these striae are visually significant.…”

“…Hypotony after glaucoma surgery can have many effects on the eye, such as worsening vision, corneal edema, hypotony maculopathy (HM), retinal hemorrhage, choroidal effusions, or choroidal hemorrhage 1–3. Vertical anterior corneal striae (ACS) are a frequent clinical observation in eyes with surgically induced hypotony and their presence indicate a 70% specificity of intraocular pressure (IOP) ≤5 mm Hg 4. However, it is not known if these striae are visually significant.…”

Clinical Significance of Corneal Striae in Thyroid Associated Orbitopathy

“…Previous studies on corneal striae were associated with abnormal intraocular pressure, especially with low IOP being reported [ 25 , 26 ]. In this study, the IOP (including in primary and upgaze) was not associated with corneal striae.…”