Combined vitrectomy and phacoemulsification with intraocular lens
implantation in severe proliferative diabetic retinopathy
Peter Senn (Luzern)
Background: Discussions about combined vitrectomy and lens surgery
(PPV+IOL) in
proliferative diabetic retinopathy (PDRP) are controversial: Severe
intra- and postoperative
complications might outweight the advantage of more precise work in
the
retinal periphery and the need for one operation only. Combined surgery
is the routine
procedure in proliferative diabetic patients at Lucerne Eye Hospital.
We report
on the results.
Patients and Method: A consecutive series of 133 eyes (105 patients)
underwent
combined PPV+IOL for PDRP between April 1996 and June 2002. Data of
117 eyes (91 patients, age 30 – 83 y,
mean 61.6, std ± 11, median 64. 55 male, 36 female) with minimal
folllow-up of 8 mth (8 – 64, median 25) were
available for retrospective analysis. The surgical technique consisted
in phacoemulsification (sclerocorneal
tunnel, curvilinear capsulorhexis), 3-port vitrectomy (including extensive
removal of the peripheral and postcapsular
vitreous, peeling and dissection of fibrovascular membranes, completing
previous panretinal photocoagulation
with endolaser or cryo to the outmost periphery), IOL implantation
in the bag, eventual endotamponade
at the end. Retrobulbar anesthesia was used in 96 %.
Results: Median preop. VA was 20/200 (handmoving – 20/25), median
VA at 6 mth 20/63 (20/400 – 20/20),
showing a significant (p < 0.0001) increase of mean 8 lines. Iris
retractors in pre-existing small pupils were used
3 times (2.5%). No significant intraoperative narrowing of the pupil
was noted. A capsular defect during phako
was created once, small capsular bites by the cutter during forced
removal of anterior vitreous ocurred seven
times (5 %) Endocapsular fixation of the IOL was safely possible in
all but two cases (99%), the rest had stable
sulcus implantation. One IOL damaged in the unfolder was exchanged
immediately after insertion. A 3–piece
acrylic IOL was used in 87 eyes (74%), silicone 3-piece in 8 (7 %),
hydrogel in 4 (3 %) and pmma in 18 (15 %).
Median IOL power was 23 dptr. (13 – 27, mean 22.8, ± 2.3).
In 12 eyes (10 %) an additional capsular tension
ring was inserted. Sclerocorneal tunnel leakage under indentation required
suturing in one procedure. Retinal
tears (various locations) were the most frequent intraoperative problem
(n = 22, 19 %). Endolaser alone was
applied in 91 eyes (78 %), combined exocryo+ endolaser in 23 (20 %)
and additional endocryo in 9 cases (7 %).
Air (n = 33, 28 %), SF6-18% (n = 17, 14 %), or Si-oil (n = 1,1%) was
used as an eventual endotamponade.
Limited postoperative fibrin formation resolving spontanously was seen
in 26 eyes (22%), another one (1 %)
responded well to injection of 10µg tpa).
Intraocular pressure problems (IOP) (>30 mmHg for < 24 h and/or >25
mmHg for >36 h) during the first postop.
week were noted in 15 cases (12 %). 8 patients (7 %) were known for
pre-existing glaucoma. Until the 6 month
controll 8 eyes (7 %) newly developed IOP problems: 5 of them were
medically compensated, two neovascula
glaucomas were stable after cyclophotocoagulation, one patient refused
further treatment. During longterm follow-
up another 6 patients (5 %) developped glaucoma (17 – 32mth postop),
5 doing well under topical medication,
one requiring cyclophotocoagulation.
Preop. anterior segment rubeosis was present in 14 eyes (12%). At 6
mth rubeosis had decreased in 7 patients
(6 %) and remained unchanged in 7 (6 %), 2 eyes (1.7%) had developed
new rubeosis postop. On long term,
an increase of anterior segment neovascularisation was noted in another
3 (2.5%), a decrease in 7 (6 %), no
change in 8 eyes (7 %).
During follow-up 7 eyes (6 %) had additional retinal laser and 2 (1.7
%) cryotherapy. YAG-laser capsulotomy
was performed in 21 eyes (18%). Secondary surgery for various reasons
was performed in overall 12 patients
(10%), in 5 of them within the first 3 mth (4.2 %): lavage for hemorrhage
(n = 3), Si-oil exchange after 7d for
focal rebleeding (n = 1), Si-oil surgery for retinal detachment after
gas resorption (n = 1). In all Si-oil cases,
the oil was removed uneventfully after 3 mth. Lavage for late vitreous
hemorrhage between 7 and 13 mth was
performed in 4 eyes (4.2%), one patient underwent lavage / central
capsulectomy combined with systemic
antibiotics for suspected low grade infecton after 7 mth, another one
hat epirentinal membrane peeling 18 mth
postvitrectomy. One patient did well for 32 mth (VA 20/32), then rapidly
developed rubeosis and went blind after another three sucessles interventions
2 eyes were lost completely within the first 6 mth: one patient developped
phtisis after early postop retinal detachment (showing up for controll
only 3 mth later), another one refused
glaucoma therapy.
Discussion: Combined surgery has major advantages,
allowing extensive work in the periphery, offering good
visibility to the posterior retina and avoiding the need for a secondary
intervention. Capsular defects (bites) by
the vitreous cutter during forced removal of the most anterior vitreous
are a typical intraoperative complication
(5 %) , rarely presenting a problem for IOL fixation. Even under direct
focal pressure the unsutured sclerocorneal
tunnels are stable. Inadvertend narrowing of the pupil does not seem
to be a problem. Minimal transient
postop. fibrin reaction ist frequent (23%), usually resolving spontanously.
Elevated IOP in the early postop
period (12%) usually responds well to treatment, its frequency indicates
the need for monitoring. The incidedence
of 7% new glaucomas within the first 6 mth has to be observed carefully.
The 1.7% occurence of new
rubeosis within 6 mth. is probably less than feared by many. There
were no long-term problems concerning IOL
or cornea. The question, whether macular function is negatively affected
by combined anterior and posterior
procedures, can not be answered in this study setting.
Conclusion: Combined surgery (PPV, Phacoemulsification and IOL implantation)
is effective. Even in unselected
cases, severe complications are rare. Combined surgery should be considered
in PDRP when lens opacities
are already present or have to be expected soon.