Intracameral platelet-rich plasma shows efficacy for severe, chronic hypotony
The combination of the fibrin's sealant properties with growth factors leads to repair and revitalization of the overfiltering areas.
Intracameral platelet-rich plasma injected into the anterior chamber can treat cases of chronic hypotony that are nonresponsive to other treatment options, according to Jorge L. Alió, MD, PhD.
“The hypothesis is that the combination of the fibrin’s sealant properties with growth factors seal the overfiltering and leaky areas and revitalize the tissue,” Alió said.
Platelet-rich plasma is a blood-derived product containing growth factors and cell adhesion molecules. Several reports have demonstrated its efficacy in various fields of medicine, including ophthalmology.
“We started using it in ocular surface disorders, such as epithelial defects, severe cases of ocular surface syndrome, punctate keratopathy and severe dry eye, which is the most frequent indication. From this we moved to the macula and then to the anterior chamber,” Alió said.
There is currently no industrial product containing platelet-rich plasma for the eye, but there are safe methods to prepare it in a hospital environment by centrifugation of a patient’s blood sample drawn at the time of treatment. Alió said that three layers are obtained: platelet-poor plasma on the top, white and red cells on the bottom, and in the middle platelet-rich plasma, which is aspirated and transferred to amber glass bottles with eye drops applicators.
The first case
Chronic hypotony may occur as a complication of glaucoma surgery, mainly due to the toxic effect of mitomycin C that makes the sclera weak or to the incidental creation of a cyclodialysis cleft following glaucoma stent implantation. Other cases may be due to poor ciliary body action or microperforations in the cornea.
“These are emergency cases that need prompt treatment to avoid severe visual loss. Hypotony can lead to corneal, macular and disc edema, maculopathy, shallow chamber, choroidal hemorrhage and retinal detachment. Treatment options include injection of viscoelastic or blood, which have short-lasting effects, or silicone oil, which causes pupillary block glaucoma. Tissue suturing or patching to reduce transscleral flow may induce the opposite effect, elevating IOP to dangerous levels,” Alió said.
He used platelet-rich plasma for the first time in a patient with bilateral Axenfeld-Rieger syndrome who developed severe ocular hypertension after penetrating keratoplasty. The patient underwent successful Ex-Press (Alcon) valve filtering surgery with MMC, but 2 years later IOP started to fall dramatically due to overfiltration and leakage from a conjunctival bleb and a wide area of thinned, atrophic sclera, both affected by MMC.
“We unsuccessfully tried all methods to block the filtering effect, and eventually, after 1 month of chronic hypotony from 0 mm Hg to 4 mm Hg and persistent corneal edema, we injected autologous platelet-rich plasma. IOP went up to 30 mm Hg within 1 hour, and 6 hours later it was 18 mm Hg,” Alió said.
The platelet-rich plasma remnants were dissolved by YAG laser 2 weeks later, the cornea regained transparency, and IOP remained stable within a normal range of 12 mm Hg to 21 mm Hg.
Potentially safe and stable treatment
According to Alió, the use of platelet-rich plasma for chronic hypotony is a radical innovation that may potentially solve problems for which other methods have failed.
“The procedure is effective, stable and risk-free. We treated seven cases, including the one I mentioned, and had no complications,” he said.
Due to its autologous nature, this treatment is safe, but there could potentially be problems with angle clogging or inflammation. That is why so far Alió has used it only in extreme cases that do not respond to conventional methods.
Once the plasma is injected in the anterior chamber, it is activated by the aqueous humor and becomes a clot that blocks filtration in the area. Within about 2 weeks, the clot becomes disorganized and eventually dissolves, but meanwhile the platelets have been promoting stable tissue healing, repair and regeneration, with no scar.
“These patients don’t relapse. We have a follow-up of almost 3 years with the first case, and IOP is stable,” Alió said.
This first case was published in July, and a paper that includes all cases is ready for publication. – by Michela Cimberle
- Abdalrahman O, et al. Eur J Ophthalmol. 2019;doi:10.1177/1120672118803515.
- For more information:
- Jorge L. Alió, MD, PhD, can be reached at Vissum Corporation, Avenida de Denia, s/n, 03016 Alicante, Spain; email: email@example.com.
Disclosure: Alió reports no relevant financial disclosures.