The clinical spectrum of posterior polymorphous dystrophy

Area of Science:

• Ophthalmology
• Genetics
• Medical Research

Background:

• Inherited corneal dystrophies encompass a range of conditions affecting the cornea.
• Previous classifications recognized distinct entities like posterior polymorphous dystrophy and congenital hereditary endothelial dystrophy.
• The phenotypic variability within families has historically complicated diagnosis and classification.

Purpose of the Study:

• To investigate the clinical spectrum and genetic basis of inherited corneal dystrophies within multiple families.
• To determine if previously described separate corneal dystrophies represent a single, variable condition.
• To identify potential genetic transmission patterns (autosomal dominant or recessive).

Main Methods:

• Clinical examination of 61 affected individuals across eight families.
• Detailed documentation of corneal abnormalities, including endothelial vesicles, stromal edema, and epithelial edema.
• Assessment for associated ocular conditions such as ocular hypertension, glaucoma, and iridocorneal adhesions.
• Pedigree analysis to determine inheritance patterns.

Main Results:

• Significant variability in corneal abnormalities was observed, even within the same family.
• Manifestations ranged from isolated endothelial vesicles to severe stromal and epithelial edema, with variable onset.
• Associated findings included ocular hypertension, open-angle glaucoma, iridocorneal adhesions, pupillary ectropion, and Descemet's membrane abnormalities.
• Autosomal dominant inheritance was observed in most families, with autosomal recessive inheritance noted in two.

Conclusions:

• The wide spectrum of clinical presentations suggests a unifying diagnosis for several previously classified corneal dystrophies.
• This familial corneal dystrophy exhibits variable expressivity and can be inherited in an autosomal dominant or recessive manner.
• Further genetic studies are warranted to elucidate the specific genes and mutations responsible for this condition.