# A biometric survey of known and prospective murine models of posterior microphthalmia-nanophthalmia

## TL;DR

This study compares mouse models of eye growth disorders to understand how genetic mutations affect eye size and shape.

## Contribution

The paper introduces new insights into the biometric effects of specific genetic mutations in mouse models of posterior microphthalmia and nanophthalmia.

## Key findings

- Mfrp, Prss56, and Adipor1 mutations cause similar eye size and shape changes in mice.
- C1qtnf5 mutations affect anterior eye growth, with changes in chamber depth and lens thickness.
- Prss56 mutants develop retinal folds not seen in other models or controls.

## Abstract

Posterior microphthalmia and nanophthalmia are related genetic conditions
that disrupt ocular growth. Here, we conducted a biometric analysis of mouse
models to assess shared features of these diseases. Three known microphthalmia
alleles (Mfrprd6,
Prss56glcr4, and
Adipor1tm1Dgen) and two
prospective alleles (C1qtnf5tm1.1(KOMP)
Vlcg and
Prss56em2(IMPC)J) were
introgressed onto the C57BL/6J (B6) genetic background and compared to B6 mice
at 1 through 12 months of age. Biometric parameters obtained using optical
coherence tomography were analyzed statistically to identify strain differences.
Fundus imaging and histological analyses were performed to assess ocular
morphology. Mfrprd6,
Prss56glcr4, and
Prss56em2(IMPC)J mice had
significantly shorter axial and posterior lengths, and longer anterior chamber
depth compared to controls at all ages studied.
Adipor1tm1Dgen mice
exhibited similar, but less severe, biometric changes. Axial length was not
significantly changed in
C1qtnf5tm1.1(KOMP)Vlcg
mice, but reduced anterior chamber depth and increased lens thickness were
observed at one month of age. Lens and corneal thicknesses were otherwise
unchanged in the models as compared to B6 controls. Corneal radius of curvature,
examined at 4 months of age, was significantly decreased in all models relative
to controls. Micropthalmia was observed independent of retinal degeneration
(Mfrprd6,
Adipor1tm1Dgen) or retinal
thickening (Prss56 mutants). Prss56 mutants
developed retinal folds that were absent from other mutants and controls. We
conclude that, in mice, Mfrp, Prss56, and
Adipor1 mutations yield similar microphthalmia phenotypes
involving both the anterior and posterior eye. Changes to anterior chamber
depth, lens thickness, and corneal curvature in
C1qtnf5tm1.1(KOMP)Vlcg mice
suggest a role of C1qtnf5 in anterior ocular growth.