206
This is a procedure that demands a high level of surgi-
cal skill and experience, with a rather flat learning curve.
The number of complications is unacceptably high. At
the present time, the very small incidence of cases that
could benefit from this procedure does not allow every
Ophthalmology department with vitreoretinal surgical
capability to gain expertise on macular translocation.
Referral this few cases to selected surgical units with the
proper human and technical resources and experience,
seems the best choice.
3. Submacular surgery
As already has been said, a variety of surgical treatments
have been developed for exudative AMD disease and one
of those are the different modalities of submacular sur-
gery. We will review these surgical approaches and there
actual role in the AMD treatment.
3.1 Surgery with subfoveal neovascular membrane
removal
In 1988, Juan and Machemer
(31)
published the first
results regarding removal of blood or fibrous submacular
complications in four AMD patients. Countless pub-
lications of retrospective studies in small numbers of
patients ensued, with no control group, describing the
benefits of this technique in stabilizing the disease, albeit
displaying reduced functional benefits
(32-34)
. The need to
determine the actual benefits of submacular surgery in
the treatment of choroidal neovascularization led to the
Submacular Surgery Trials (SSTs). One of the objectives
of this study was to determine whether surgery not only
stabilizes vision for the various types of AMD lesions but
also increases vision with actual repercussion in the qual-
ity of life of these patients
(35)
.
In the pilot trial used as a test to determine the best
method to be used in this multicentre, randomized, con-
trolled study no reason was found to prefer submacu-
lar surgery instead of laser photocoagulation in AMD
patients with similar lesions to those displayed by study
patients
(36)
.
Several surgical techniques are described in the litera-
ture. In summary, these techniques include standard
pars plana vitrectomy, with or without posterior hya-
loid membrane removal; posterior retinotomy followed
by infusion of subretinal saline solution or r-TPA into
lesions with a large haemorrhagic component, mem-
brane mobilization and its removal with surgical forceps,
followed by eventual aspiration of blood or clot aspira-
tion, depending on the situation. Possible intraocular
haemorrhages may be controlled by increasing the intra-
ocular pressure, either by raising the irrigation bottle or
using heavy perfluorocarbon liquids. The procedure is
finished with a fluid-air exchange, followed by gas buff-
ering, maintaining the patient in the prone position until
gas reabsorption
(37-40)
.
Due to the physiopathology of this disease, it was
observed in histopathological studies that inadvertent
and undesired removal of the pigment epithelium often
occurs during membrane removal, especially for type
1 membranes. The absence of the pigment epithelium
leads to loss or atrophy of photoreceptors and choriocap-
illaries, which unfavorable visual recovery
(41)
. The per-
centage of removed epithelium is variable but may reach
significantly high values, as observed in the SSTs, where
the pigment epithelium was involved in 84% of removed
membranes
(42)
. Therefore, both the functional results and
the impact on the quality of life observed for the various
subgroups considered in the SSTs, compared to natural
disease progression, led the authors not to recommend
submacular surgery as a treatment option
(43-46)
.
3.2 Autologous pigment epithelium transplants
As previously referred, the poor results achieved with
surgical removal of subfoveal membranes, largely due to
resulting atrophy or rupture of the photoreceptor-retinal
pigment epithelium complex, led some groups to com-
bine neovascular membrane removal with simultaneous
transplant of iris or retinal pigment epithelium, with the
objective of restoring normal subretinal conditions
(47-49)
.
The surgical technique used is similar to that used in sub-
macular surgery, in addition to the aspiration and subse-
quent pigment epithelial cell transplant procedures.
I had the good fortune and the pleasure of assisting in a
surgical procedure performed during my training at the
Eye Hospital of Rotterdam with Dr. van Meurs, a pio-
neer in this field (A.M.); therefore, it is his technique
which is described in general terms: complete pars plana
vitrectomy after inducing posterior hyaloid membrane
detachment, paramacular retinotomy and removal of
the subfoveal membrane, creation of a peripheral retinal
detachment in the walled off inferior retina by the tran-
sretinal injection of Ringer’s solution into the subretinal
space, removal of the detached retina with the vitrec-
tome, aspiration of pigment epithelial cells with a micro-
pipette connected to an insulin syringe, centrifugation of
aspirated material, reinjection through the retinotomy of
