Diabetic RetinopathyDiabetic Retinopathy in Primary in Primary CareCare

EpidemiologyEpidemiology

Diabetes is one of the most serious challenges to health care woDiabetes is one of the most serious challenges to health care worldrld--wide. wide. According to recent projections it will affect 239 million peoplAccording to recent projections it will affect 239 million people by 2010e by 2010--doubling in prevalence since 1994.doubling in prevalence since 1994.

Diabetes will affect 28 million in western Europe, 18.9 million Diabetes will affect 28 million in western Europe, 18.9 million in North America in North America 138.2 million in Asia, 1.3 million in 138.2 million in Asia, 1.3 million in AustralasiaAustralasia..

Diabetes mellitus is the most common cause of blindness amongst Diabetes mellitus is the most common cause of blindness amongst individuals individuals of workingof working--age ( 20age ( 20--65 years). The prevalence of blindness due to DR in 65 years). The prevalence of blindness due to DR in Western Communities is estimated as between 1.6Western Communities is estimated as between 1.6--1.9/ 100,0001.9/ 100,000

About 8% of UK BD8 registrations. About 8% of UK BD8 registrations. ( The World Health Organisation (1992) ( The World Health Organisation (1992) definition of blindness is vision less than 3/60 in the better definition of blindness is vision less than 3/60 in the better eye with best eye with best available spectacle correction. 4available spectacle correction. 4thth Leading cause of blindness globallyLeading cause of blindness globally--about 2 about 2 million blind.million blind.

Regional projections of the Regional projections of the prevalence of diabetes (millions) in prevalence of diabetes (millions) in

2010 2010

PresentationPresentation

About 2% of type 2 diabetics have macular About 2% of type 2 diabetics have macular oedema at diagnosis and 10.2% have other signs oedema at diagnosis and 10.2% have other signs of DR already present when their diabetes is of DR already present when their diabetes is discovered. discovered. Mitchell and coMitchell and co-- workers found that 15.8 % of workers found that 15.8 % of

undiagnosed diabetics in an elderly Australian undiagnosed diabetics in an elderly Australian population had signs of DR, according to the population had signs of DR, according to the recent recent Blue Mountains Eye StudyBlue Mountains Eye Study. Indeed it may . Indeed it may often take from 9often take from 9--12 years for type 2 diabetes to 12 years for type 2 diabetes to be diagnosedbe diagnosed

Some Key factsSome Key facts

About 95% reduction in rate of blindnessAbout 95% reduction in rate of blindness--most treatable case of irreversible loss of most treatable case of irreversible loss of vision.vision.12% of type 1 diabetics were blind after 30 12% of type 1 diabetics were blind after 30 years of diabetic life.years of diabetic life.Control of diabetes and hypertension is as Control of diabetes and hypertension is as important as laser therapy in prevention of important as laser therapy in prevention of blindness.blindness.

A classification of diabetic retinopathyA classification of diabetic retinopathy

NonNon--proliferativeproliferative diabetic retinopathy (NPDR)/ BDRdiabetic retinopathy (NPDR)/ BDRMicroaneurysmsMicroaneurysmsDot and blot haemorrhagesDot and blot haemorrhagesHard ( intraHard ( intra--retinal ) exudatesretinal ) exudatesPPDRPPDR

ProliferativeProliferative diabetic retinopathydiabetic retinopathyNeovascularizationNeovascularization of the retina, optic disc or irisof the retina, optic disc or irisLate DRLate DR-- fibrovascularfibrovascular proliferation proliferation

Maculopathy Maculopathy Clinically significant macular oedema (CSME )Clinically significant macular oedema (CSME )IschaemicIschaemic MaculopathyMaculopathyDiffuse maculopathyDiffuse maculopathyMACULOPATHY IS LEADING CAUSE OF BLINDNESSMACULOPATHY IS LEADING CAUSE OF BLINDNESS

NonNon--proliferativeproliferative diabetic retinopathy (NPDR)diabetic retinopathy (NPDR)

Pathogenesis of Diabetic Pathogenesis of Diabetic MicroangiopathyMicroangiopathy

Hyperglycaemia causesHyperglycaemia causes--BM thickening BM thickening non non enzymaitcenzymaitc glycosylationglycosylationincreased free radical activityincreased free radical activityincreased flux through the increased flux through the polyolpolyol pathwaypathwayosmotic damageosmotic damage

Haemostatic abnormalities of the microcirculationHaemostatic abnormalities of the microcirculation--It has also been postulated that platelet abnormalities in diabeIt has also been postulated that platelet abnormalities in diabetics may tics may contribute to diabetic retinopathy. There are three steps in placontribute to diabetic retinopathy. There are three steps in platelet coagulation: telet coagulation: initial adhesion, secretion, and further aggregation. It has beeinitial adhesion, secretion, and further aggregation. It has been shown that the n shown that the platelets in diabetic patients are "stickier" than platelets of platelets in diabetic patients are "stickier" than platelets of nonnon--diabetics They diabetics They secrete secrete prostaglandinsprostaglandins that cause other platelets to adhere to them that cause other platelets to adhere to them (aggregation) and blockage of the vessel and endothelial damage.(aggregation) and blockage of the vessel and endothelial damage.

MicroaneurysmsMicroaneurysms

DR IS A MICROVASCULAR COMPLICATION OF DIABETESDR IS A MICROVASCULAR COMPLICATION OF DIABETES--KEY KEY LESION IS MICROANEURYSMS.LESION IS MICROANEURYSMS.

Retinal Retinal microaneurysmsmicroaneurysms are focal dilatations of retinal capillaries, 10 to are focal dilatations of retinal capillaries, 10 to 100 microns in diameter, and appear as red dots. They are usuall100 microns in diameter, and appear as red dots. They are usually y seen at the posterior pole, especially temporal to the fovea. seen at the posterior pole, especially temporal to the fovea.

Beginning as dilatations in areas in the capillary wall where Beginning as dilatations in areas in the capillary wall where pericytespericytesare absent, are absent, microaneurysmsmicroaneurysms are initially thinare initially thin--walled. Later, endothelial walled. Later, endothelial cells proliferate and lay down layers of basement membrane matercells proliferate and lay down layers of basement membrane material ial around themselves. around themselves.

Fibrin and erythrocytes may accumulate within the aneurysm. DespFibrin and erythrocytes may accumulate within the aneurysm. Despite ite multiple layers of basement membrane, they are permeable to watemultiple layers of basement membrane, they are permeable to water r and large molecules, allowing the accumulation of water and lipiand large molecules, allowing the accumulation of water and lipid in the d in the retina. retina.

MicroaneurysmsMicroaneurysms

Retinal HaemorrhagesRetinal Haemorrhages

When the wall of a capillary or When the wall of a capillary or microaneurysmmicroaneurysm is sufficiently weakened, is sufficiently weakened, it may rupture, giving rise to an it may rupture, giving rise to an intraretinalintraretinal haemorrhage. If the haemorrhage. If the hemorrhagehemorrhage is deep (i.e., in the inner nuclear layer or outer is deep (i.e., in the inner nuclear layer or outer plexiformplexiformlayer), it usually is round or oval ("dot or blot") layer), it usually is round or oval ("dot or blot")

Dot haemorrhages appear as bright red dots and are the same sizeDot haemorrhages appear as bright red dots and are the same size as as large large microaneurysmsmicroaneurysms. Blot haemorrhages are larger lesions they are . Blot haemorrhages are larger lesions they are located within the mid retina and often within or surrounding arlocated within the mid retina and often within or surrounding areas of eas of ischaemiaischaemia..

If the If the hemorrhagehemorrhage is more superficial and in the nerve is more superficial and in the nerve fiberfiber layer, it layer, it takes a flame or splinter shape, which is indistinguishable fromtakes a flame or splinter shape, which is indistinguishable from a a hemorrhagehemorrhage seen in seen in hypertensivehypertensive retinopathy. They often absorb slowly retinopathy. They often absorb slowly after several weeks. Their presence strongly suggests the coafter several weeks. Their presence strongly suggests the co--existence existence of systemic hypertension.of systemic hypertension.

When an ophthalmologist sees numerous splinter haemorrhages in aWhen an ophthalmologist sees numerous splinter haemorrhages in adiabetic patient, the patient's blood pressure must be checked bdiabetic patient, the patient's blood pressure must be checked because ecause a frequent complication of diabetes is systemic hypertension. a frequent complication of diabetes is systemic hypertension.

Cotton Wool SpotsCotton Wool Spots

Cotton wool spots result from occlusion of retinal Cotton wool spots result from occlusion of retinal prepre--capillary arterioles supplying the nerve fibre capillary arterioles supplying the nerve fibre layer with concomitant swelling of local nerve fibre layer with concomitant swelling of local nerve fibre axons. Also called "soft exudates" or "nerve fibre axons. Also called "soft exudates" or "nerve fibre layer infarctions" they are white, fluffy lesions in layer infarctions" they are white, fluffy lesions in the nerve fibre layer. the nerve fibre layer. FluoresceinFluorescein angiographyangiographyshows no capillary perfusion in the area of the soft shows no capillary perfusion in the area of the soft exudateexudate. They are very common in DR, especially . They are very common in DR, especially if the patient is also if the patient is also hypertensivehypertensive. .

Cotton Wool SpotsCotton Wool Spots

Hard exudates (IntraHard exudates (Intra--retinal lipid exudates)retinal lipid exudates)

Hard exudates ( IntraHard exudates ( Intra--retinal lipid exudates ) retinal lipid exudates ) are yellow deposits of lipid and protein are yellow deposits of lipid and protein within the sensory retina. Accumulations of within the sensory retina. Accumulations of lipids leak from surrounding capillaries and lipids leak from surrounding capillaries and microaneuryismsmicroaneuryisms, they may form a , they may form a circinatecircinatepattern. pattern. HyperlipidaemiaHyperlipidaemia may correlate with may correlate with the development of hard exudates. the development of hard exudates.

Hard exudates ( IntraHard exudates ( Intra--retinal lipid retinal lipid exudates)exudates)

Accumulations of Accumulations of lipids leak from lipids leak from surrounding capillaries surrounding capillaries and and microaneuryismsmicroaneuryisms, , they may form a they may form a circinatecircinate pattern.pattern.

NonNon--proliferativeproliferative diabetic retinopathy diabetic retinopathy (NPDR)(NPDR)

Late non Late non proliferativeproliferative changeschanges--PreproliferativePreproliferative DRDR

IntraIntra--retinal retinal microvascularmicrovascular abnormalities ( IRMA) are abnormalities ( IRMA) are abnormal, dilated retinal capillaries or may abnormal, dilated retinal capillaries or may represent represent intraretinalintraretinal neovacularizationneovacularization which has which has not breached the internal limiting membrane of the not breached the internal limiting membrane of the retina.retina.They indicate severe nonThey indicate severe non--proliferativeproliferative diabetic diabetic

retinopathy that may rapidly progress to retinopathy that may rapidly progress to proliferativeproliferative retinopathy. retinopathy. Venous beading has an appearance resembling Venous beading has an appearance resembling sausagesausage--shaped dilatation of the retinal veins. It is shaped dilatation of the retinal veins. It is another sign of severe non another sign of severe non proliferativeproliferative diabetic diabetic retinopathy.retinopathy.Blot Blot heamorrhagesheamorrhages ++++++

Late non Late non proliferativeproliferative changeschanges

ProliferativeProliferative diabetic retinopathydiabetic retinopathy

Retinal Retinal ischaemiaischaemia due to due to widespread capillary non widespread capillary non perfusion results in the perfusion results in the production of production of vasoproliferativevasoproliferativesubstances and to the substances and to the development of development of neovascularizationneovascularization. . NeovascularizationNeovascularization can can involve the retina, optic involve the retina, optic disc or the irisdisc or the iris( ( rubeosisrubeosisiridisiridis))

ProliferativeProliferative diabetic retinopathydiabetic retinopathy

RubeosisRubeosis iridisiridis is a sign of severe is a sign of severe proliferativeproliferativedisease, it may cause intractable glaucoma.disease, it may cause intractable glaucoma.

Bleeding from fragile new vessels involving the retina Bleeding from fragile new vessels involving the retina or optic disc can result in vitreous or retinal or optic disc can result in vitreous or retinal haemorrhage. Retinal damage can result from haemorrhage. Retinal damage can result from persistent vitreous haemorrhage.persistent vitreous haemorrhage.

PrePre--retinal haemorrhages are often associated with retinal haemorrhages are often associated with retinal retinal neovascularizationneovascularization, they may dramatically , they may dramatically reduce vision within a few minutes. reduce vision within a few minutes.

ProliferativeProliferative diabetic retinopathydiabetic retinopathy

ProliferativeProliferative diabetic retinopathydiabetic retinopathy

ProliferativeProliferative diabetic retinopathydiabetic retinopathy

ProliferativeProliferative diabetic retinopathydiabetic retinopathy

Bleeding into vitreous Bleeding into vitreous from new vessels, a from new vessels, a common occurrence in common occurrence in proliferative proliferative disease.disease.

Iris Iris NeovascularisationNeovascularisation

Late DiseaseLate Disease

Contraction of Contraction of associated fibrous associated fibrous tissue formed by tissue formed by proliferativeproliferative disease disease tissue can result in tissue can result in deformation of the deformation of the retina and retina and tractionaltractionalretinal detachmentretinal detachment

Late ComplicationsLate Complications

Diabetic Diabetic Maculopathy Maculopathy and and Macular OedemaMacular Oedema

Diabetic Diabetic MaculopathyMaculopathy is now is now the leading cause of the leading cause of legal blindness in legal blindness in diabetics in Western diabetics in Western Communities. Communities.

The MaculaThe MaculaThe macula subserves high resolution The macula subserves high resolution central and colour vision. It is horizontally central and colour vision. It is horizontally oval, 5mm in diameter. The foveola forms oval, 5mm in diameter. The foveola forms the central floor. It has a diameter of the central floor. It has a diameter of 0.35mm. It is the thinnest part of the retina. 0.35mm. It is the thinnest part of the retina. Its entire thickness consists only of cone Its entire thickness consists only of cone photoreceptors and it subserves the most photoreceptors and it subserves the most acute vision. acute vision.

The macula has the highest concentration of The macula has the highest concentration of photoreceptors and is the the area where the photoreceptors and is the the area where the RPE is most metabolically active and as a RPE is most metabolically active and as a consequence most likely to suffer the consequence most likely to suffer the consequence of enzymatic failure over time consequence of enzymatic failure over time with the accumulation of metabolic debris with the accumulation of metabolic debris and lipofuscin .and lipofuscin .

Macular OedemaMacular Oedema

Macular oedema is an important Macular oedema is an important manifestation of DR because it is now manifestation of DR because it is now the leading cause of legal blindness in the leading cause of legal blindness in diabetics. diabetics.

The intercellular fluid comes from The intercellular fluid comes from leaking leaking microaneurysmsmicroaneurysms or from diffuse or from diffuse capillary leakage capillary leakage

Macular OedemaMacular Oedema

Macular OedemaMacular Oedema

IschaemicIschaemic MaculopathyMaculopathy

Maculopathy in type 1 diabetics is often due Maculopathy in type 1 diabetics is often due to drop out of the to drop out of the perifovealperifoveal capillaries with capillaries with non perfusion and the consequent non perfusion and the consequent development of an development of an ischaemicischaemic maculopathymaculopathy..

IschaemicIschaemic maculopathy is not uncommon in maculopathy is not uncommon in type 2 diabetics, maculopathy in this group type 2 diabetics, maculopathy in this group may show both changes due to may show both changes due to ischaemiaischaemia but but also retinal thickening. also retinal thickening.

IschaemicIschaemic MaculopathyMaculopathy

Flourescein Flourescein AngiographyAngiography

Primary CarePrimary Care-- Screening for DRScreening for DR

The current consensus of opinion from The current consensus of opinion from Europe and the United States is that Europe and the United States is that screening for DR byscreening for DR by suitably trained and suitably trained and experienced practitionersexperienced practitioners is cost effective and is cost effective and results in reduced morbidity due to blindness. results in reduced morbidity due to blindness.

All diabetics over the age of 12 years should All diabetics over the age of 12 years should have their fundus examined annually.have their fundus examined annually.

www.diabeticwww.diabetic--retinopathyretinopathy--screening.screening.nhsnhs..ukuk//

Direct Direct ophthalmoscopyophthalmoscopy

Studies from the UK have shown sensitivity Studies from the UK have shown sensitivity levels for the detection of sightlevels for the detection of sight--threatening threatening diabetic retinopathy of 41diabetic retinopathy of 41--67% for general 67% for general practitioners, 48practitioners, 48--82% for optometrists, 65% 82% for optometrists, 65% for an ophthalmologist, and 27for an ophthalmologist, and 27--67% for 67% for diabetologistsdiabetologists and hospital physicians using and hospital physicians using direct direct ophthalmoscopyophthalmoscopy..

Slit Lamp Slit Lamp BiomicroscopyBiomicroscopy

The direct ophthalmoscope enables adequate The direct ophthalmoscope enables adequate examination of only the posterior pole whilst the examination of only the posterior pole whilst the indirect ophthalmoscope provides insufficient indirect ophthalmoscope provides insufficient magnification. magnification. Slit lamp examination ( using either indirect Slit lamp examination ( using either indirect ophthalmoscopyophthalmoscopy with a convex aspheric lens or with a convex aspheric lens or diagnostic contact lens) yields much more diagnostic contact lens) yields much more information by providing stereoscopic assessment information by providing stereoscopic assessment of retinal thickening and of retinal thickening and proliferativeproliferative retinopathy.retinopathy.

Screening for DRScreening for DR

PhotoscreeningPhotoscreening will not will not always detect subtle signs always detect subtle signs of DR , such as retinal of DR , such as retinal thickening, but a success thickening, but a success rate of 80rate of 80--92% in detecting 92% in detecting DR is claimed by DR is claimed by researchers.researchers.Annual digital fundus Annual digital fundus photography is now the photography is now the recommended modality of recommended modality of screeningscreening

A protocol for diabetic screening and A protocol for diabetic screening and MonitoringMonitoring

Type 2 diabetic patients without retinopathy should be assessed Type 2 diabetic patients without retinopathy should be assessed at at the time of diagnosis and annually thereafter. the time of diagnosis and annually thereafter.

Patients with diabetes and mild nonPatients with diabetes and mild non--proliferativeproliferative retinopathy should retinopathy should be assessed every 12 months by a suitably experienced be assessed every 12 months by a suitably experienced practitioner.practitioner.

Screening doctors should always look, in particular, for the onsScreening doctors should always look, in particular, for the onset of et of macular oedema. macular oedema.

Type 1 diabetics rarely develop retinopathy until after eight yType 1 diabetics rarely develop retinopathy until after eight years ears of diabetic life. The current recommendation is that type 1 diabof diabetic life. The current recommendation is that type 1 diabetics etics should be screened after puberty or age 12 years.should be screened after puberty or age 12 years.

Primary ocular care of diabeticsPrimary ocular care of diabetics

Just as effective as laser therapy in reducing Just as effective as laser therapy in reducing blindness.blindness.

Eye is the window of the soulEye is the window of the soul--factors which factors which prevent retinopathy also prevent other multiprevent retinopathy also prevent other multi--system complications of diabetes.system complications of diabetes.

In particular there is a strong relationship between In particular there is a strong relationship between DR and nephropathyDR and nephropathy-- marovascularmarovascular compicationscompicationsmay also be prevented.may also be prevented.

Primary ocular care of diabeticsPrimary ocular care of diabetics

Factors that can worsen diabetic Factors that can worsen diabetic retinopathyretinopathy-- and indeed the general and indeed the general prognosis of diabetes, include poor diabetic prognosis of diabetes, include poor diabetic control, obesity,systemic hypertension, control, obesity,systemic hypertension, hyperlipidaemiahyperlipidaemia, cigarette smoking, diabetic , cigarette smoking, diabetic nephropathy, anaemia, pregnancy and nephropathy, anaemia, pregnancy and cataract surgerycataract surgery

GlycaemicGlycaemic controlcontrol

It is now proven that good diabetic control It is now proven that good diabetic control may slow the development and progression may slow the development and progression of diabetic retinopathy in both type 1 and type of diabetic retinopathy in both type 1 and type 2 diabetes. 2 diabetes.

Overall there was a 30% reduction in Overall there was a 30% reduction in microvascularmicrovascular end points in the group end points in the group exhibiting good exhibiting good glycaemicglycaemic control.control.

HbA1c HbA1c The HbA1C test is currently one of the best ways to check The HbA1C test is currently one of the best ways to check diabetes is under control.diabetes is under control.

Coincidentally the sugar/HbA1C numbers for good control Coincidentally the sugar/HbA1C numbers for good control are rather similar though: sugar levels 5.5are rather similar though: sugar levels 5.5--6.5 6.5 mmolsmmols/l half /l half an hour before meals versus 5an hour before meals versus 5--7% HbA1C.7% HbA1C.

When should the HbA1C be measured?When should the HbA1C be measured?

If diabetes is controlled (an HbA1C lower than 7%), every If diabetes is controlled (an HbA1C lower than 7%), every 33--6 months. 6 months.

GlycatedGlycated haemoglobin in relation to the risk of retinopathy in haemoglobin in relation to the risk of retinopathy in conventionally treated (top) and intensively treated patients.conventionally treated (top) and intensively treated patients.

Aetiology and pathogenesis of the development of obesity Aetiology and pathogenesis of the development of obesity

and nonand non--insulin dependent diabetes mellitusinsulin dependent diabetes mellitus

American Heart Association American Heart Association Recommendations 2000Recommendations 2000

At least five servings of fruits and vegetables daily. At least five servings of fruits and vegetables daily. Six or more servings of whole grains and legumes (beans). Six or more servings of whole grains and legumes (beans). Six ounces of lean meat or poultry per day. Six ounces of lean meat or poultry per day. At least two servings of fatty fish, such as tuna or salmon per At least two servings of fatty fish, such as tuna or salmon per week week No more than one alcoholic drink per day for women and two for mNo more than one alcoholic drink per day for women and two for men, en, for those who consume alcohol. for those who consume alcohol. To prevent weight gain, the new guidelines also recommend at leaTo prevent weight gain, the new guidelines also recommend at least 30 st 30 minutes of brisk walking daily. The walking can be done all at ominutes of brisk walking daily. The walking can be done all at once or nce or in segments throughout the day. in segments throughout the day. The guidelines also stress the importance of The guidelines also stress the importance of preventing obesitypreventing obesity, which , which research has shown can contribute to medical problems such as research has shown can contribute to medical problems such as diabetes, high blood pressure and heart disease. The associationdiabetes, high blood pressure and heart disease. The association's diet 's diet plan recommends a gradual weight loss no more than one to two plan recommends a gradual weight loss no more than one to two pounds per week using a simple process of cutting calories and pounds per week using a simple process of cutting calories and increasing exercise. increasing exercise.

Tightening Tightening GlycaemicGlycaemic controlcontrol

Tightening of Tightening of glycaemicglycaemic control may initially produce control may initially produce worsening of retinopathy. The postulated mechanism worsening of retinopathy. The postulated mechanism includes lowering of retinal blood low or overproduction of includes lowering of retinal blood low or overproduction of IGFIGF--1 by the liver.1 by the liver.

It is therefore recommended that monitoring of retinopathy It is therefore recommended that monitoring of retinopathy is increased if major changes to is increased if major changes to glycaemicglycaemic control are control are made particularly in previously poorly controlled diabetics. made particularly in previously poorly controlled diabetics. Ideally Ideally glycatedglycated haemoglobinhaemoglobin ( HbA1c)( HbA1c) should be should be maintained below 7%. maintained below 7%.

Systemic hypertension and DR in type 2 Systemic hypertension and DR in type 2 diabetesdiabetes

Recent literature indicates that there is a Recent literature indicates that there is a striking correlation between the presence of striking correlation between the presence of systemic hypertension and progression of systemic hypertension and progression of diabetic retinopathy. diabetic retinopathy. It is important to note that many type 2 It is important to note that many type 2 diabetics will need a combination of antidiabetics will need a combination of anti--hypertensivehypertensive agents to lower their blood agents to lower their blood pressure. pressure.

HypertensionHypertension

Systemic hypertension and DR in type 2 Systemic hypertension and DR in type 2 diabetesdiabetes

The hypertension in diabetes study was launched within the origThe hypertension in diabetes study was launched within the original inal UKPDS study in 1987. UKPDS study in 1987.

The study compared diabetics whose blood pressure was tightly The study compared diabetics whose blood pressure was tightly controlled ( BP < 150/85)with ACE inhibitors and beta blockers wcontrolled ( BP < 150/85)with ACE inhibitors and beta blockers with a ith a cohort whose blood pressure was less tightly controlled. (BP <18cohort whose blood pressure was less tightly controlled. (BP <180/ 95 ) 0/ 95 ) Median follow up was 8.4 years.Median follow up was 8.4 years.

The reduction of The reduction of macrovascularmacrovascular events was significant with a 32% events was significant with a 32% reduction in diabetes related deaths. There was a 44% reduction reduction in diabetes related deaths. There was a 44% reduction in in stroke and a 34% reduction in overall stroke and a 34% reduction in overall macrovascularmacrovascular disease.disease.

UKPDS is a unique study in that it also looked at UKPDS is a unique study in that it also looked at microvascularmicrovascular end end points in type 2 diabetics. Overall the tight control group had points in type 2 diabetics. Overall the tight control group had a 37% a 37% reduction in reduction in microvascularmicrovascular disease.disease.

This effect was manifested as a reduction of the risk of havinThis effect was manifested as a reduction of the risk of having to g to undergo laser photocoagulation by 34%. undergo laser photocoagulation by 34%.

Systemic hypertension and DR in type 2 Systemic hypertension and DR in type 2 diabetesdiabetes

The risk of reduction of visual acuity was lowered The risk of reduction of visual acuity was lowered by 47%.by 47%.

AtenololAtenolol and and CaptoprilCaptopril were equally effective in were equally effective in reducing the risk of progression of retinopathy in reducing the risk of progression of retinopathy in type 2 diabetics. type 2 diabetics.

The Hypertension Optimal Treatment ( HOT ) The Hypertension Optimal Treatment ( HOT ) study indicates that the lowest incidents of cardiac study indicates that the lowest incidents of cardiac events occurs when blood pressure is lowered to events occurs when blood pressure is lowered to 82.6 mmHg diastolic and 136 mmHg systolic. 82.6 mmHg diastolic and 136 mmHg systolic.

Systemic hypertension and DR in type 2 Systemic hypertension and DR in type 2 diabetesdiabetes

Each 1 mmHg of blood Each 1 mmHg of blood pressure rise causes a pressure rise causes a 1.3% increase in the 1.3% increase in the number of problems number of problems that may develop.that may develop.Target BP 130/80Target BP 130/80

AngiotensinAngiotensin Converting Enzyme (ACE) Converting Enzyme (ACE) inhibitors in Type 1 diabetesinhibitors in Type 1 diabetes

The EUCLID study is currently investigating the The EUCLID study is currently investigating the prophylactic treatment of type 1 diabetics with the prophylactic treatment of type 1 diabetics with the AngiotensinAngiotensin Converting Enzyme (ACE) Inhibitor Converting Enzyme (ACE) Inhibitor Lisinopril Lisinopril and the progression of nephropathy and and the progression of nephropathy and other other microvascularmicrovascular disease including DR . Preliminary disease including DR . Preliminary reports are of a specific benefit are encouraging, with a reports are of a specific benefit are encouraging, with a claimed 50% reduction in progression of DR in type 1 claimed 50% reduction in progression of DR in type 1 diabetics.diabetics.

The study did not look at maculopathyThe study did not look at maculopathy-- so that so that implications are unclear for type 2 diabetics, although implications are unclear for type 2 diabetics, although no specific advantage of ACE inhibitors (no specific advantage of ACE inhibitors (CaptoprilCaptopril) over ) over AtenololAtenolol was seen in UKPDS.(31)was seen in UKPDS.(31)

HyperlipidaemiaHyperlipidaemia and diabetic maculopathyand diabetic maculopathy

There is evidence in the literature that There is evidence in the literature that diabetics who have diabetics who have exudativeexudativemaculopathy with extensive lipid exudes maculopathy with extensive lipid exudes benefit from active treatment of benefit from active treatment of hyperlipidaemiahyperlipidaemia..StatinsStatins are very helpful.are very helpful.

Diabetic nephropathyDiabetic nephropathy

Diabetic nephropathy accelerates the Diabetic nephropathy accelerates the progression of retinopathy, especially progression of retinopathy, especially macular oedema, macular oedema, inter inter aliaalia via increased via increased levels of fibrinogen and lipoprotein and levels of fibrinogen and lipoprotein and associated hypertension.associated hypertension.The visual prognosis is often better if the The visual prognosis is often better if the nephropathy is treated by renal nephropathy is treated by renal transplantation rather than by dialysistransplantation rather than by dialysisAny anaemia resulting from renal disease Any anaemia resulting from renal disease

must be aggressively treated.must be aggressively treated.Diabetic retinopathy is a common prelude to Diabetic retinopathy is a common prelude to the development of renal disease. the development of renal disease.

Diabetic nephropathyDiabetic nephropathy

InvestigationsInvestigationsU+E’s U+E’s CreatinineCreatinineProteinuriaProteinuriaMorning Albumin/Morning Albumin/CreatinineCreatinine ratioratioFormal 24h Formal 24h creatininecreatinine clearanceclearance

PregnancyPregnancy

Diabetic retinopathy may worsen during pregnancy. Diabetic retinopathy may worsen during pregnancy. Screening should therefore be undertaken at Screening should therefore be undertaken at confirmation of pregnancy and every two months confirmation of pregnancy and every two months during pregnancy if no retinopathy is present, or during pregnancy if no retinopathy is present, or monthly, if retinopathy is present. monthly, if retinopathy is present.

Retinal status should not preclude pregnancy since Retinal status should not preclude pregnancy since contemporary methods of management can result in contemporary methods of management can result in satisfactory ocular and pregnancy outcomes even in satisfactory ocular and pregnancy outcomes even in the presence of advanced diabetic the presence of advanced diabetic microvascularmicrovasculardisease providing sufficient care is takendisease providing sufficient care is taken

PregnancyPregnancy

Pregnancy may accelerate the progression of Pregnancy may accelerate the progression of diabetic retinopathy. Frequency of monitoring NPDR diabetic retinopathy. Frequency of monitoring NPDR should therefore be increased.should therefore be increased.

Women who begin a pregnancy with no retinopathy, Women who begin a pregnancy with no retinopathy, the risk of developing diabetic retinopathy is about the risk of developing diabetic retinopathy is about 10%. 10%.

Women who begin pregnancy with poorly controlled Women who begin pregnancy with poorly controlled diabetes and who are suddenly brought under strict diabetes and who are suddenly brought under strict control frequently have severe deterioration of their control frequently have severe deterioration of their retinopathy and do not always recover after deliveryretinopathy and do not always recover after delivery

The role of the ophthalmic hospitalThe role of the ophthalmic hospital

Monitoring DR

Liasing with other health professionals

Education

Specialist therapeutics

Laser TherapyLaser Therapy

Laser Laser photocoagulation photocoagulation causes a retinal burn causes a retinal burn which is visible on which is visible on fundoscopyfundoscopy. . Retinal and optic disc Retinal and optic disc neovascularizationneovascularization can can regress with the use of regress with the use of retinal laser retinal laser photocoagulation. photocoagulation.

PanretinalPanretinal laser photocoagulation for laser photocoagulation for proliferativeproliferative DRDR

The mainstay of treatment of The mainstay of treatment of diabetic retinopathy is retinal diabetic retinopathy is retinal laser photocoagulation. laser photocoagulation.

Laser therapy is highly effective; Laser therapy is highly effective; the rate of severe visual loss at the rate of severe visual loss at 2 years due to 2 years due to proliferativeproliferativedisease can be reduced by disease can be reduced by 60%. 60%.

RubeosisRubeosis iridisiridis requires urgent requires urgent panretinalpanretinal photocoagulation to photocoagulation to prevent ocular pain and prevent ocular pain and blindness from glaucoma.blindness from glaucoma.

PanretinalPanretinal laser photocoagulationlaser photocoagulation

PanretinalPanretinal laser photocoagulation for laser photocoagulation for proliferativeproliferative DRDR

Macular laser therapyMacular laser therapy

The indications for laser therapy now include The indications for laser therapy now include CSME which is treated with a macular laser grid or CSME which is treated with a macular laser grid or treatment of focal lesions such as treatment of focal lesions such as microaneuryismsmicroaneuryisms. . Early referral and detection of disease is important Early referral and detection of disease is important as treatment of maculopathy is far more as treatment of maculopathy is far more successful if undertaken at an early stage of the successful if undertaken at an early stage of the disease process. disease process. There is a reduction in the rate of loss of vision by There is a reduction in the rate of loss of vision by 50% at 2 years with macular grid therapy. 50% at 2 years with macular grid therapy.

Macular laser therapyMacular laser therapy

Complications of laser photocoagulationComplications of laser photocoagulation

Although laser therapy can be highly effective in preventing bliAlthough laser therapy can be highly effective in preventing blindness, it is ndness, it is associated with numerous complications. associated with numerous complications. Retinal vein occlusion can follow inadvertent photocoagulation oRetinal vein occlusion can follow inadvertent photocoagulation of a retinal vein. f a retinal vein. Rarely, there may be loss of central acuity from inadvertent phoRarely, there may be loss of central acuity from inadvertent photocoagulation of tocoagulation of the fovea. the fovea. Vitreous haemorrhage can follow photocoagulation of retinal or Vitreous haemorrhage can follow photocoagulation of retinal or choroidalchoroidalvessels. vessels. There may be visual field restriction, decreased contrast sensitThere may be visual field restriction, decreased contrast sensitivity, impaired ivity, impaired night vision or impaired colour vision. night vision or impaired colour vision. Visual field constriction may impair fitness to drive although oVisual field constriction may impair fitness to drive although ophthalmologists phthalmologists increasingly strive to avoid this most undesirable problem, for increasingly strive to avoid this most undesirable problem, for example by example by avoiding confluent laser burns. avoiding confluent laser burns. A recent study indicates that 88% of diabetics who have undergonA recent study indicates that 88% of diabetics who have undergone laser e laser photocoagulation would pass the photocoagulation would pass the EstermanEsterman binocular field test which is the legal binocular field test which is the legal criterion for fitness to drive in the United Kingdom, even if bocriterion for fitness to drive in the United Kingdom, even if both eyes were th eyes were treated. 42% of treated. 42% of uniocularuniocular fields failed to make the criterion of a 120 degree fields failed to make the criterion of a 120 degree horizontal field. Patients who have already lost the sight in onhorizontal field. Patients who have already lost the sight in one eye therefore e eye therefore have a significant chance of failing to meet legal parametershave a significant chance of failing to meet legal parameters for fitness to drive for fitness to drive in the United Kingdom.in the United Kingdom.Headache can sometimes follow laser therapy. The headache is usHeadache can sometimes follow laser therapy. The headache is usually ually relieved with rest and simple analgesia. relieved with rest and simple analgesia. Glaucoma Glaucoma must be excluded if the must be excluded if the headache is severe or persistent. headache is severe or persistent.

Cataract surgeryCataract surgery

Cataract surgery may lead Cataract surgery may lead to progression of preto progression of pre--existing macular oedema existing macular oedema and and proliferativeproliferative diabetic diabetic retinopathy. However, retinopathy. However, cataracts may impede cataracts may impede fundoscopyfundoscopy and therefore and therefore interfere with the treatment interfere with the treatment of diabetic retinopathy. of diabetic retinopathy. If possible, diabetic If possible, diabetic retinopathy should be retinopathy should be treated prior to cataract treated prior to cataract surgerysurgery

VITRECTOMY IN DIABETIC PATIENTSVITRECTOMY IN DIABETIC PATIENTS

VitrectomyVitrectomy, plays a vital , plays a vital role in the management of role in the management of severe complications of severe complications of diabetic retinopathy. diabetic retinopathy.

The major indications are The major indications are nonclearingnonclearing vitreous vitreous hemorrhagehemorrhage, traction , traction retinal detachment, and retinal detachment, and combinedtractioncombinedtraction//rhegmatrhegmatogenousogenous retinal retinal detachment. detachment.

SummarySummaryBDA recommends BDA recommends treatment which aims for treatment which aims for the following: the following: Blood pressure levels of Blood pressure levels of 140/80 mm Hg or below 140/80 mm Hg or below HbA1c levels of 7.0% or HbA1c levels of 7.0% or below below Fasting blood glucose Fasting blood glucose levels of 4 levels of 4 -- 7 7 mmolmmol/litre /litre Self monitored blood Self monitored blood glucose levels before glucose levels before meals between 4 and 7 meals between 4 and 7 mmolmmol/ /

SummarySummaryPrimary care is just as Primary care is just as effective as laser therapy effective as laser therapy in reducing blindness.in reducing blindness.All diabetics over the age All diabetics over the age of 12 years should have of 12 years should have their fundus examined their fundus examined annually.annually.Factors that can worsen Factors that can worsen diabetic retinopathydiabetic retinopathy--include poor diabetic include poor diabetic control, obesity, systemic control, obesity, systemic hypertension, hypertension, hyperlipidaemiahyperlipidaemia,diabetic ,diabetic nephropathy.nephropathy.

Web SitesWeb Sites

www.www.diabeticretinopathydiabeticretinopathy.org..org.ukukwww.eyetextbook.org.ukwww.eyetextbook.org.uk

ScreeningScreeningwww.diabeticwww.diabetic--retinopathyretinopathy--screening.screening.nhsnhs..ukuk//

AcknowledgementsAcknowledgementsDr. David Kinschuck, Dr. Robert HarveyDr. David Kinschuck, Dr. Robert Harvey