Hyaluronan (2009, 2014-2016) & Macular Holes
Learn more about macular holes.
Several studies, taken together, suggest a connection between low levels of hyaluronan in the vitreous and incidence of macular hole.
One of the causes of macular holes is retinal detachment.
In a small study researchers found that patients with retinal detachment have low levels of hyaluronan and increased activity of the enzyme hyaluronidase which degrades hyaluronan. They did also note that patients with macular holes, but no retinal detachment did not have the same low levels of hyaluronan.
Researchers: K. Kaprinis, et al,
Published: Decreased hyaluronan concentration during primary rhegmatogenous retinal detachment, European Journal of Ophthalmology, November, 2016.
Editor's Note: While there is not a direct connection between hyaluronan absence and incidence of macular hole, it is true that retinal detachment is considered one of the causes of macular holes. We feel that macular holes may be caused by a number of imbalances and hyaluronan absence may be one of these contributing factors.
There is a close relationship between the health of the structure of the vitreous (the gel-containing center sphere of the eye) and the formation of macular holes. Researchers note that when the vitreous degrades macular holes form.
In one study researchers found that the structure of the vitreous is weakened when vitreous tissue is submerged in enzymes that cause hyaluronic acid (and other macro-molecules) to deteriorate. In other words, the destruction of hyaluronic acid in the vitreous body weakens the structure of the vitreous. Following such submersion the vitreous structure contained significantly less hyaluronic acid.
Their conclusion was that the macromolecule hyaluronan acts synergistically with collagen and proteglycans to support vitreous health.
Researchers: B.A. Filas, Q. Zhang, et al,
Published: Enzymatic degradation identifies components responsible for the structural properties of the vitreous body, Investigative Ophthalmology & Visual Science, January, 2014.
During surgery for 26 patients with macular holes and 52 patients with diabetic retinopathy, doctors collected samples of the vitreous fluid. Upon analysis they found found that in all of the macular hole patients and in half of the diabetic retinopathy patients the hyaluronan levels were signficantly lower the older the patient. They also found that after surgery high-molecular hyaluronan levels appeared to not increase in the vitreous fluid following surgery.
Researchers: H. Itakura, S. Kishi, et al
Published: Decreased vitreal hyaluronan levels with aging, Ophthalmologica, October, 2009.
Editor's Note: Hyaluronic acid or substances containing large amounts of hyaluronic are commonly used in surgery to repair macular holes due to their protective value.1, 2
1. M. Hirano, et al, Case report: successful closure of a large macular hole secondary to uveitis using the inverted internal limiting membrane flap technique, BMC Ophthalmology, July, 2015.
2. M. F. Abdelkader, H.M. Moharram, Internal Limiting Membrane Closure of Idiopathic Macular Hole, Journal of Clinical & Experimental Ophthalmology, 2015.