Medical Care
Management of PPMD varies widely based on the differences in severity of corneal decompensation. Many patients who are asymptomatic and show minimal signs of PPMD can be treated conservatively and do not require therapy.
Ruptured corneal bullae should be treated similar to a corneal abrasion.
Hyperosmotic saline drops and ointments may be used in cases of corneal failure with corneal edema.
Secondary glaucoma may require medical or surgical management.
A bandage soft contact lens may be used as a temporary measure to treat bullous keratopathy.
Future considerations: As is the case for many genetic conditions, the CRISPR/Cas system may eventually help those afflicted with this condition. The CRISPR/Cas system offers a broad scope of gene editing and engineering to correct underlying genetic causes in corneal dystrophies. Corneal tissue--specific gene correction in vitro with minimal off-target effects and optimal gene correction efficiency followed by their successful surgical implantation, or in vivo CRISPR administration targeting pathogenic genes finds a way to explore therapeutic intervention for corneal dystrophies. (footnote #30 - Asia-Pacific Journal of Ophthalmology 11(4):p 346-359, July/August 2022. )
Surgical Care
The risk factors for more advanced disease, requiring surgery, include increased intraocular pressure and iridocorneal adhesions.
Corneal transplantation is usually reserved for patients with substantially decreased visual acuity or when the disease is advanced and painful due to ruptured epithelial bullae. Penetrating keratoplasty (full thickness corneal transplantation) has been the transplant procedure of choice in the past. The newer techniques of posterior endothelial keratoplasty, such as Descemet membrane stripping endothelial keratoplasty (DSEK) and Descemet membrane endothelial keratoplasty (DMEK), have been shown to be successful. [9, 10]
Rare cases of corneal graft failure due to recurrence of PPMD in the donor graft have been reported, but the most common problem following a corneal transplant is related to uncontrolled glaucoma. [11]
To treat pain in eyes without good visual potential, other procedures, such as anterior stromal micropuncture, excimer laser phototherapeutic keratectomy, amniotic membrane transplantation, and conjunctival flap surgery, can also be considered.
When glaucoma medications no longer adequately control the intraocular pressure, glaucoma laser or incisional surgery may be required to prevent glaucomatous optic nerve damage. Surgery with limited success is often seen in patients with peripheral anterior synechiae without gonioscopy and elevated intraocular pressure. Poor intraocular pressure control, even with surgical intervention, is observed.
Consultations
Depending on the severity of the condition, consultation with corneal and glaucoma subspecialists may be warranted.
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Slit lamp image demonstrates posterior corneal vesicles and opacities in linear bands and other polymorphous configurations typical of posterior polymorphous corneal dystrophy.
