Diabetic awareness and education
Bangladeshi National Diabetes 
Awareness 1995. Healthy eating, 
exercise and good diabetic control.
Lion Club. Educating the diabetic 
patients on the importance of 
blood sugar control.

Campaign to highlight awareness of diabetes mellitus in the USA.
Section 9 Vitrectomy in Diabetic Eye Disease
(for a larger retina view click on the picture)
Vitrectomy is a specialized procedure which is the domain of
appropriately trained vitreo-retinal surgeons. Vitrectomy is used 
to achieve specific goals, which may limit or halt the progress of 
advanced diabetic eye disease. These are:
  • to remove vitreous opacity (commonly vitreous haemorrhage,

  • also intra-ocular fibrin, or cells) and/or fibrovascular proliferation
    (severe extensive proliferative retinopathy; anterior
    hyaloidal fibrovascular proliferation)
  • to allow completion of panretinal laser photocoagulation (with

  • the endolaser, introduced into the vitreous cavity or with the
    indirect laser ophthalmoscope), or direct ciliary body laser 
  • to relieve retinal traction, tractional displacement or ectopia, 

  • traction detachment by removal or dissection of epiretinal 
    membranes, in cases of non-rhegmatogenous retinal 
  • to achieve retinal reattachment by closure of breaks and 

  • placement of internal tamponade (in cases of combined traction/
    rhegmatogenous detachments)
  • to remove the posterior hyaloid face in some cases of diffuse 

  • macular oedema with posterior hyaloid face thickening.
Simple vitreous haemorrhage is a relative indication for vitreous 
surgery, DRS studies have shown that several factors should 
considered: the patient's age, the rapidity of progress and degree 
of severity of diabetic eye disease, the patient's appreciation of risks 
and benefits of surgery, and the patients ability to co-operate with 
surgery, and in particular with post-operative positioning, and 
supplemental laser photocoagulation where indicated. Various types 
of simple vitreous haemorrhage occurs as discussed below:
9.2.1 Severe non-clearing vitreous haemorrhage
Vitreous haemorrhage often clears within a matter of days to weeks, 
and it is usually possible to achieve delivery of initial or supplemental 
panretinal laser photocoagulation without vitrectomy (see section on 
lasers). If laser photocoagulation is not possible, or vitreous 
haemorrhage persists for more than one month then vitrectomy should 
be considered since maculopathy and/or proliferative disease may 
progress unchecked, thus compromising the final visual result.
Patients with NIDDM are less likely to have severe progressive 
proliferative retinopathy and while they also gain benefit from early 
surgery, as opposed to deferred surgery (surgery deferred for more 
than 6 months) the benefit is less. These patients should nonetheless 
have surgery within 3 to 6 months from onset of persistent non-clearing 
vitreous haemorrhage.
Regular (2-4) weekly ultrasonic examinations are required to ensure 
early detection of retinal detachment, and clinical biomicroscopy to 
detect iris or iridocorneal angle neovascularization, or haemolytic/ghost 
cell glaucoma. Patients with any of these complications should be 
considered for early vitrectomy47-49.
Surgical goals and procedure
For this indication the surgical goal is to remove the vitreous
opacity through a 3-port pars plana vitrectomy procedure. The
posterior hyaloid face should be removed (this is a structural support 
for fibrovascular proliferation and its removal usually prevents 
subsequent reproliferation), and initial or supplemental panretinal laser 
photocoagulation should be performed to prevent reproliferation,
anterior hyaloidal fibrovascular proliferation, and entry site 
complications (fibrovascular ingrowth).
9.2.2 Non-clearing post-vitrectomy haemorrhage
Recurrence of vitreous haemorrhage is common in the early post-
vitrectomy period (2-4 weeks) but usually clears spontaneously within a
short time. In all cases where the retina cannot be adequately visualized, 
it is essential to confirm the absence of underlying retinal detachment 
with ultrasonography. If cavity haemorrhage does not clear within 2-3
weeks, revision surgery should be considered.
Surgical goals and procedures
The surgical goal is to remove the haemorrhage, and treat the cause. 
Revision normally requires a 3-port pars plana vitrectomy to allow an 
adequate internal search for the source of bleeding. In particular, 
examination of the previous entry sites is necessary to detect and 
treat anterior hyaloidal and/or entry site fibrovascular proliferation.
9.2.3 Dense pre-macular haemorrhage
Subhyaloid haemorrhages may be seen with or without associated
intra-gel haemorrhage (Figure 27) these are localized to the immediate 
vicinity of neovascular complexes. Most such haemorrhages respond 
to supplemental panretinal laser photocoagulation. Dense subhyaloid 
haemorrhage occurs in the pre-macular area, in areas of localized 
posterior vitreous detachment, or in an existing premacular bursa.
Progressive fibrovascular proliferation develops in non-resolving 
pre-macular haemorrhage d involves the cortical vitreous gel with 
subsequent macular traction detachment or ectopia.
Indications for vitrectomy in this type of haemorrhage include severe
visual loss (for example in only eyes), failure of regression or 
resumption of haemorrhage after supplemental laser photocoagulation  
the presence of significant subhyaloid pre-macular haemorrhage in eyes 
with good pre-existing panretinal laser photocogualtion47-49.
Figure 27 Subhyaloid haemorrhage 
occupying the premaulcar bursa 
Surgical goals and procedures
A 3-port pars plana vitrectomy is performed taking care to remove the 
posterior hyaloid face, particularly from the posterior pole and the 
temporal arcades. Haemorrhage is removed, residual membrane 
dissected and supplemental panretinal endolaser photocoagulation is 
placed if needed. Long standing cases are more likely to require 
significant membrane dissection with its attendant risk of iatrogenic 
retinal break formation.
Some surgeons have suggested that first-line treatment for dense pre-
macular haemorrhages is YAG laser therapy to the pre-hyaloid vitreous 
cortex, avoiding the macular area, thus releasing the trapped blood. This 
procedure is safe and may allow early visualization of diabetic 
maculopathy50-51. This is a promising procedure but is not yet standard 
practice and requires further evaluation.
Elevated intraocular pressures may be caused by vitreous haemorrhage 
specifically in those eyes with a disrupted anterior hyaloid face after 
previous vitrectomy surgery, or in aphakic eyes with vitreous haemorrhage. 
"Erythroclasts" pas from the vitreous cavity into the anterior chamber and 
obstruct the trabecular meshwork. It is important to differentiate this 
condition from steroid induced intra-ocular pressure elevation, since many 
of these patients may also be suing topical steroid drops. If the intraocular 
pressure remains elevated despite medical therapy after one to 3 weeks, 
surgery should be performed.
Surgical goals and procedures
Revision pars plana vitrectomy with removal of all vitreous cavity and anterior 
chamber haemorrhage is the preferred surgical procedure. Glaucoma filtering 
surgery is usually not required.
9.4.1 Tractional macular ectopia and detachment
Traction retinal ectopia or detachment involving the macula is the leading 
indication for vitrectomy surgery in PDR at the present time. Tension is 
exerted on the posterior hyaloid face or cortical vitreous remnants, and 
indirectly on the retina by contraction of fibrovascular proliferative tissue 
resulting in retinal striae, macular ectopia, macular distortion and traction 
retinal detachment (Figure 28). Since the hazards of surgery are high in 
this condition, vitrectomy is generally limited to those eyes with 
a) involvement of the macula; b) evidence of a progressive extra-macular 
traction retinal detachment; c) combined traction/rhegmatogenous retinal 
detachment which threatens to involve the macula (see below). Surgery 
in cases with macular involvement for more than 6 months is usually 
associated with little or no functional improvement and is not 
Figure 28 Diabetic tractional detachment (arrow).
Surgical goals and procedures
In addition to removal of media opacity, specific goals include release of 
tractional components by removal of fibrovascular membranes, closure of 
persistently bleeding vessels and treatment of any iatrogenic retinal breaks. 
Cases with pure tractional elevation will experience spontaneous post-operative 
retinal reattachment and macular remodelling as a result of successful surgery. 
Anatomic success has been reported in between 64% to 80% of patients 
(with a 6 month follow-up) with visual function improvement in 26% 
to 65%49,52.
9.4.2 Combined traction - rhegmatogenous retinal detachment
While most extra-macular traction retinal detachments will remain stable 
for many years even if these tissue complexes are highly elevated, in some 
patients the force of the fibrovascular traction is sufficient to create a 
retinal tear. These tears may also occur in relation to previous laser 
photocoagulation scars. These tears are frequently not identified 
Clinically, a rhegmatogenous retinal detachment caused by fibrovascular 
proliferation presents with a convex configuration rather than the concave 
contour of a tractional, non-rhegmatogenous detached retina. In addition, 
white (hydration) lines in the inner retina are more characteristic of a 
rhegmatogenous component. Surgery is indicated if there is sudden visual 
loss, evidence of progressive peripheral combined traction/rhegmatogenous 
retinal detachment, or evidence of progressive iris rubeosis.
Some patients (typically young adult type I diabetics with a history of 
diabetes since childhood) are seen with a pattern of active fibrovascular 
proliferation that progresses despite extensive panretinal laser 
photocoagulation. These eyes have a high risk of severe visual loss and 
blindness. The Diabetic Retinopathy Vitrectomy Study Group compared 
standard laser and vitrectomy indications (with vitrectomy for vitreous 
haemorrhage, or traction macular detachment) in a randomized fashion 
with early vitrectomy surgery, in  total of 370 eyes. The number of 
patients experiencing preservation of good visual function (20/40 or better) 
was almost twice as high in the early vitrectomy group (44%) compared to 
the conventional management group (28%) after 4 years of follow-up. 
However, the proportion of eyes with severe visual loss or blindness was 
similar in both groups and this stage was reached earlier in the early 
vitrectomy group. Clinical characteristics which warrant referral for 
vitrectomy, even in the absence of extensive laser photocoagulation, 
include widespread fibrovascular proliferation (three disc diameters 
or more of fibrovascular tissue).
It is to be emphasized that these patients frequently have extensive 
proliferation as their sole indication and do not necessarily have vitreous 
haemorrhage or macular tractional displacement. While these patients 
should receive panretinal laser photocoagulation, the presence of high 
risk characteristics should indicate vitreo-retinal referral at an early stage.
Surgical goals and procedures
A 3-port pars plana vitrectomy is performed, with great ce being taken 
to remove all detectable posterior hyaloid face which is typically adherent 
to the retina.
Anterior segment neovascularization which is mild and non-progressive 
may be safely monitored. Progressive iris or angle neovascularization 
requires panretinal laser photocoagulation, and if vitreous haemorrhage 
prevents adequate and effective retinal laser photocoagulation, 
vitrectomy with endolaser photocoagulation is indicated. Patients with 
established neovascular glaucoma may undergo combined surgery, 
comprising pars plana vitrectomy with extensive endolaser photo-
coagulation and in some cases with additional direct ciliary body 
photocoagulation. This surgery is combined with silicone oil exchange 
in some eyes or with glaucoma filtration surgery in others. 
Fibrovascular proliferation on the anterior hyaloidal surface or its remnant 
is typically seen after vitrectomy in severe ischaEmic eyes of patients with 
type 1 diabetes mellitus. This fibrous tissue, which causes contraction of 
adjacent tissue and may cause peripheral traction retinal detachment, 
posterior iris displacement and lens displacement or recurrent vitreous 
haemorrhage, is highly vascular and difficulty to treat. in some patients 
this process may be localized to the area of the entry site and is 
associated with typical sentinel vessels on the adjacent episclera and 
sclera55. Anterior hyaloidal fibrovascular proliferation may also occur 
after cataract extraction in patients with active proliferative disease56.
Surgical goals and procedure
The surgical goal is to remove all fibrovascular tissue. This requires 
basal vitrectomy, lensectomy, membrane dissection and extensive, 
confluent laser photocoagulation to the peripheral retina and pars plana, 
often combined with scleral buckling surgery and silicone oil exchange.
Epidemiology Clinical features Risk factors Screening
Lasers and lenses. NVD,, NVE.. Maculopathy
Vitrectomy. Cataract Special problems Counselling
References.. AAO guidelines Atlas of Retinopathy Contact lenses
Main index Main page.