Background
Myopic foveoschisis is a rare form of a tractional maculopathy, which occurs in
patients with advanced myopia. The contraction of the posterior hyaloid exerts
tangential traction on the retinal surface with a subsequent continuous splitting of the
retinal layers. This pathological process can advance inadvertently to severe visual
loss and in extreme cases to a macular retinal detachment or macular hole. Surgical
therapy of this pathology using vitrectomy with internal limiting membrane peeling is
successful, but the thinning of the foveal retina can result during the post-operative
phase in a macular hole with subsequent visual loss. We report on a modified
surgical technique, which spares the fovea and may reduce the risk for macular hole
formation.
Objectives
The aim of this project was to evaluate a novel surgical technique whereby the
epiretinal tissue is not peeled over the whole macular area but in a fovea-sparing
manner. This means that a small area of the internal limiting membrane overlying the
fovea is left in situ which thereby prevents a weakening of the perifoveal tissue and
possible macular hole formation in the post-operative phase.
Methods
We observed retrospectively six patients with myopic foveoschisis operated on using
this novel technique. The surgical technique comprised a standard 23 gauge pars
plana vitrectomy, epiretinal membrane and internal limiting membrane peeling in a
fovea-sparing manner and an intraocular gas tamponade using 23% SF6 gas. The
role of this tamponade and a face-down position during 5 days was to make sure that
the previously dissociated retinal layers will reconnect to the residual normal retina.
The macula was examined pre- and post-operatively using optical coherence
tomography (OCT) and fundus photography. Post-operative visual acuity recovery
and image analysis of the foveoschisis using OCT was evaluated with particular
emphasis on the incidence of an early stage macular hole formation. The follow-up of
these patients was on average seven months.
Criteria for inclusion :
- High myopia (> -8 Diopters)
- Foveoschisis diagnosed on OCT
Criteria for exclusion :
- Foveoschisis with macular hole
- Previous vitrectomy with entire internal limiting membrane peeling
Results
Mean best-corrected pre-operative visual acuity was 0.87 ± 0.56 logMAR, which
increased to 0.60 ± 0.40 logMAR at the end of follow-up. The retinal thickness, as
measured by optical coherence tomography, decreased from 799 ± 352 micrometers
to 318 ± 60 micrometers at the end of follow-up 7.8 ± 5.7 months. No case developed
a macular hole.
Conclusions
Myopic foveoschisis is a rare clinical entity and a randomised clinical trial for the
surgical therapy of this pathology will thus unfortunately not be feasible in the future.
Clinical management of this disorder will largely depend on clinical experience and
low grade evidence case control studies or simple case series. With this caveat we
are nevertheless convinced that our research can shed new light on the foveasparing
internal limiting membrane peeling technique as a promising surgical therapy
for foveoschisis, which improves foveal anatomy and retinal function. Due to the
sparing of the fovea, this surgical technique may reduce the risk of macular hole
formation in the post-operative period.