ROPARD Online Education Section Introduction
Evolution of Retinal Detachment and
Treatment of early stages of Retinopathy of Prematurity
Introduction to Retinopathy of Prematurity
Retinopathy of prematurity was first described by
Terry and Kinsey in the early 1940s when they described a process called retrolental
fibroplasia. Since that time, Arnold Patz and Everett Kinsey developed the concept
that increased oxygen might be responsible for retinopathy of prematurity, then called
retrolental fibroplasia.
With the evolution of the International Classification of Retinopathy of Prematurity (ICROP), much of the confusion with regards to retinopathy of prematurity was
resolved because better communication was allowed between examiners.
It was later proven that oxygen was not the sole
culprit of retinopathy of prematurity by John Flynn. The advancing retinal vascular
disease of retinopathy of prematurity can progress to retinal detachment and lead to
blindness.
What is retinopathy of prematurity?
Retinopathy of prematurity (ROP) has been divided into five stages. Stages 1 and 2 customarily get better on their
own. Some eyes, however, go on to Stage 3
retinopathy of prematurity. This happens
when new blood vessels start to grow from the retina toward the center of the eye, forming
a ridge between retina that has blood vessels in the back of the eye, and the retina that
does not have blood vessels in the front of the eye.
This difference in the blood vessels of the retina is because the premature baby
has not had the time while in the womb to allow the blood vessels within the retina to
grow all the way from the optic nerve in the back of the eye to the front of the eye.
Stage 3 ROP
Stage 3 ROP exists when these disturbing new
blood vessels grow out from the ridge in the retina toward the center of the eye. If this blood vessel growth becomes severe and is
accompanied by “plus” disease, the child may reach the point where treatment of
the peripheral retina with laser (or rarely freezing) treatment is performed. “Plus” disease is defined as enlarged
and twisting blood vessels in the back part of the eye.
Plus Disease
Peripheral retinal treatment can reduce, but not
eliminate, the chance of the ROP progressing to the potentially blinding stages 4 and 5. When stage 4 or 5 ROP is reached, the retina is
detached and other therapies can be performed.
Stage 4 ROP
One such
therapy is scleral buckling, which involves encircling the eyeball with a silicone band to
try and reduce the pulling on the retina.
Other
therapies include vitrectomy (removal of the gel-like substance called the vitreous that
fills the back of the eye).
Sometimes the
removal of the lens as well is required during vitrectomy to try and eliminate as much
pulling as possible from the retinal surface.
Removal
of the lens is performed if the retina is touching the back surface of the lens, which would make it impossible to enter the eye
for vitreous surgery without damaging the retina.
When scleral
buckling is considered the appropriate procedure, the success rate is 70% retinal reattachment. Vitreous surgery for stage 4B, where the
retina responsible for central vision is detached, or stage 5, where all the retina is
detached, had a success rate of 76% reattachment.
The
child’s vision after these procedures were in the ranges of:
20/60 to 20/300 for 15% of eyes
20/60 to 20/800 for 30% of eyes
20/60 to 20/1900 for 48% of eyes (ambulatory vision)
light perception for 72% of eyes
Ambulatory vision is defined as being able to see
objects and move around a room without stumbling or bumping into obstacles. Unfortunately, 28% of children even with
appropriate management and vitreous surgery end up with no light perception.
Recently, vitreous surgery is being performed
earlier, at stage 4A, where the retina responsible for central vision remains attached,
and shows promise of success rates of up to 90%.
Visual
results in this population are not available currently, but are suspected to be perhaps
better than when surgery is performed at stage 4B or 5.
The development of vision is dependent on many
factors, much of which we probably don’t fully understand, but certainly issues
relative to the child’s glasses needs, central nervous system development, and
developing the “wiring” for vision based on competition between the two eyes are
all factors that enter into the child’s final visual acuity. Fortunately, children are able to adapt to lower
levels of vision and use their vision at levels much higher than what their measured
visual acuity might suggest.
Children with a
visual acuity of 20/200, which would be classified as legally blind, very often function
at a level much better than that when they are
observed
performing their daily tasks.
Certainly there is much progress to be made in
the area of retinopathy of prematurity and other forms of pediatric retinal detachment
that hopefully will yield even better visual results.
Some of these things will be aided by the development of drugs that can control
this new blood vessel growth, as well as developments of microelectronics and other tissue
manipulation techniques.
Module 1
The following module will outline the
International Classification of Retinopathy of Prematurity treatment and management of
stage 3 retinopathy of prematurity as well as management of stages 4 and 5 retinopathy of
prematurity.
|
