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from use of contact lenses used to treat keratoconus;
there was no more progression of refractive changes in
family members after adolescence.
17
Isolated cases of OI
type I and keratoconus have also been reported.
18
South African family of Indian ancestry with four broth-
ers and two cousins having severe OI with blindness due
to vitreous hyperplasia, corneal opacities and secondary
glaucoma with multiple skeletal anomalies, but this con-
dition has been reclassified as osteoporosis-pseudoglioma
syndrome due to mutations in LRP5.
25-27
Keratoglobus
Keratoglobus is a bilateral ectatic disorder that is non-
progressive or minimally progressive with generalized
corneal thinning, usually in the periphery, that produces
globular protrusion of the cornea. No iron rings are
observed and there is minimal scarring. While hydrops
is less frequent than in keratoconus, keratoglobus
patients are more prone to corneal perforation and rup-
ture after minimal trauma or even when there is no his-
tory of trauma. Associated scleral thinning has also been
described. Corneas are normal in size or with slightly
increased diameter. Hyams et al. reported keratoglobus
in a family with blue sclera and joint hypermobility with
features overlapping OI.
19
Others have also reported on
the association of keratoglobus and blue sclera.
20,21
Variations in Corneal Size
Both small corneal diameter
15
and large cornea -
megalocornea
28
- have been reported in cases of OI.
Refractive Errors and OI: Myopia , Hyperopia
and Astigmatism
Refractive errors are aberrations that cause poor focus
of light onto the retina and thereby result in blurred
vision. Refractive errors may be corrected optically by
glasses or contact lenses. The prevalence of refractive
errors in the OI population is unknown. Refractive errors
include myopia, hyperopia and astigmatism.
Myopia - or near sightedness - is a reported feature
of many connective tissue disorders including OI.
29-32
The focal plane of light entering the eye is anterior to the
retina in this condition which leads to poor visual acuity
for distant objects but improved visual acuity for close
objects. In refractive myopia, the near sightedness may
be caused by refractive errors in the cornea, refractive
errors in the lens or a combination of the two. In axial
myopia, the near sightedness is caused by elongation
of the eye such that the increased axial length of the eye
causes the myopia. Myopia can be corrected by glasses
or contact lenses.
Hyperopia - or far sightedness - is another refrac-
tive error that may occur with OI. In hyperopia, the focal
plane of light entering the eye is posterior to the retina,
resulting in sharper visual acuity for objects at distance
and decreased visual acuity for closer objects. In refrac-
tive hyperopia, this far sightedness may be caused by
refractive errors in the cornea, lens or both. In axial
hyperopia, the far sightedness is due to a short axial
length for the eye. Treatment is also through refractive
correction, including glasses or contact lenses.
Astigmatism is the refractive error caused by optical
aberrations of the cornea and/or lens away from a per-
fectly spherical refractive configuration. Astigmatism is
also commonly found in many connective tissue disor-
ders, including OI.
29
As with hyperopia and myopia, the
condition may be corrected by glasses or contact lenses.
Cornea Plana
Cornea plana is a congenital development disorder
with a marked reduction in the curvature of the cornea.
The radius of curvature is often less than 40 diopters -
often 30 to 33 diopters - similar to the radius of curvature
of the sclera. In cornea plana, the cornea has a “latter”
configuration that reduces vision because of high refrac-
tive error. Desvignes reported cornea plana in a patient
with Lobstein's disease (OI type I) in 1967.
22
Descemet's Membrane Detachments
The Descemet's membrane lining the posterior endo-
thelial surface of the cornea may spontaneously open and
separate from the rest of the cornea in disorders like kera-
toconus. This rupture of Descemet's membrane causes
separation of the endothelial cells from the rest of the cor-
neal stroma and leads to stromal hydration, loss of cor-
neal clarity and loss of vision. In keratoconus, this corneal
hydration from Descemet's membrane rupture is called
hydrops. Jaeger reported a case of Descemet's membrane
rupture and keratoschisis in a patient with OI (van der
Hoeve-Lobstein syndrome) in 1970.
23
With the develop-
ment of reined corneal surgical techniques in the last
decade, Gorovoy et al. reported the successful repair of
a spontaneous Descemet's membrane detachment using
Descemet stripping automated endothelial keratoplasty
(DSAEK) in a 25-year-old OI patient in 2012.
24
This OI
patient was also suspected of having keratoconus.
Corneal Opacities
Small or large regions of corneal opacities have also
been reported in OI. The opacities may be small and
visually insignificant or very large and part of the major
reasons for visual disability. Beighton et al. reported on a
Anterior Segment Anomalies including Reiger's
Anomaly and OI
Abnormalities in the anterior segments of the eyes
have been reported in a patient with OI and some
