Binocular membranous cataract associated with binocular retinal detachment

The novel mutation P36R in LRP5L contributes to congenital membranous cataract via inhibition of laminin γ1 and c-MAF

PURPOSE

The present study investigated a pathogenic mutation and its mechanism on membranous cataract in a congenital membranous cataract family.

METHODS

An autosomal dominant four-generation Chinese congenital membranous cataract family was recruited and whole-exome sequencing was performed to screen for sequence variants. Candidate variants were validated using polymerase chain reaction and Sanger sequencing. Wild-type and mutant low-density lipoprotein receptor-related protein 5-like (LRP5L) plasmids were constructed and transfected into human lens epithelial cells (HLE B-3) and human anterior lens capsules. The cell lysates, nuclear and cytoplasmic proteins, and basement membrane components of HLE B-3 cells were harvested. LRP5L and laminin γ1 were knocked down in HLE B-3 cells using specific small-interfering RNA. The protein expression levels of LRP5L, laminin γ1, and c-MAF were detected using immunoblotting and immunofluorescence.

RESULTS

We identified a novel suspected pathogenic mutation in LRP5L (c.107C > G, p.P36R) in the congenital membranous cataract family. This mutation was absent in 300 normal controls and 300 age-related cataract patients. Bioinformatics analysis with PolyPhen-2 and SIFT suggested that LRP5L-P36R was pathogenic. LRP5L upregulated laminin γ1 expression in the cytoplasmic proteins of HLE B-3 cells and human anterior lens capsules, and LRP5L-P36R inhibited the effects of LRP5L. LRP5L upregulated c-MAF expression in the nucleus and cytoplasm of HLE B-3 cells, and LRP5L-P36R inhibited c-MAF expression via inhibition of laminin γ1.

CONCLUSION

Our study identified a novel gene, LRP5L, associated with congenital membranous cataract, and its mutant LRP5L-P36R contributed to membranous cataract development via inhibition of laminin γ1 and c-MAF.

Clinical Characteristics and Surgical Procedures for Children with Congenital Membranous Cataract

Objective

In a group case series, the clinical characteristics of congenital membranous cataract in children were studied to establish a system of classification and determine the surgical method suited for each type.

Methods

Children (18 eyes) with congenital membranous cataract were examined by slit lamp, ultrasound biomicroscopy, and operating microscopy to classify cataracts. The clinical characteristics of congenital membranous cataract and its feature related to the surgical method were analyzed.

Results

Five major types of congenital membranous cataracts were classified. All of the surgeries were successful. Anterior and posterior capsulorhexis was performed using Klöti RF capsulotomy tips. The capsular flap was removed, and anterior vitrectomy was performed using a vitrectomy cutter. Postoperative complications included posterior capsule opacification in 16.7% of the patients.

Conclusion

Ultrasound biomicroscopy was used successfully to classify congenital membranous cataracts prior to surgery. Anterior and posterior capsulorhexis was performed using Klöti RF capsulotomy tips, and capsulectomy was performed using a vitrectomy cutter. These were effective techniques and should be considered for congenital membranous cataract removal surgery. This trial is registered with registration number chiCTR-OOC-17010913.

Cataract surgery in a patient with unilateral cataracta membranacea

Cataracta membranacea (CM) is a rare condition characterized by the remnants of lens capsules and fibrous proliferation that develops secondary to lens matter liquefaction and absorption. Although CM is usually bilateral and may be associated with other congenital anomalies and poor visual prognosis; it can rarely be seen in the adults with involvement of only one eye. Reported herein, is a case of 57-year-old man who presented with CM in his right eye and underwent successful in-the-bag intraocular lens implantation with good visual outcome.