1. Retina
By:Abeer Hussein

2. Special structures of the retina :
Introduction & Anatomy :
Special structures of the retina :
1)Optic disc:
Formed by axons of ganglion cells that leave the eye to form the optic nerve.
Located medial to the fovea centralis.
Lacks receptors → insensitive to light → blind spot (physiologic scotoma).
Has a central depression called the optic cup.

3. An oval-shaped yellow spot on the lateral side of the optic disk.
Introduction & Anatomy :
2)macula:
An oval-shaped yellow spot on the lateral side of the optic disk.
near the center of the posterior wall of the retina.
Lacks blood vessels.
Contains the fovea centralis:
A central depression in the macula
 (foveola)
Only has cones
each of which is connected to one singular ganglion cell.
Point of sharpest vision (100% visual acuity).

4. Diseases of the retina:
Diseases of the retina may lead to:
visual impairment, visual field loss, and more complex disorders
 such as metamorphopsia (distorted vision) and clouding.

5. Retinal diseases •Macular dysfunction
•Peripheral retinal dysfunction>>The area of the retina outside the macula. The peripheral retina gives us our side (peripheral) vision and night vision.

6. Symptoms of retinal disease
•Macular dysfunction
The central part of the macula (the fovea ) is responsible for fine
resolution.
•Blurred central vision.
•Distorted vision ( metamorphopsia ) caused by a disturbance in the arrangement of the photoreceptors such as that which occurs in macular oedema,a grid of straight lines appears wavy and parts of the grid may appear blank. People can first notice they suffer with the condition when looking at mini-blinds in their home
.A reduction ( micropsia ) or enlargement ( macropsia ) of object size may also occur if the photoreceptors become stretched apart or compressed together.
•The patient may notice areas of loss of the central visual field ( scotomata ) if part of the photoreceptor layer becomes covered, e.g. by blood, or if the photoreceptors are destroyed.

7. •Peripheral retinal dysfunction
The patient complains of:
•Loss of visual field (usually detected clinically when a significant amount of the peripheral retina is damaged).
Small areas of damage, e.g. small haemorrhages, do not produce clinically detectable defects.
The field loss may be absolute, for example in a branch retinal artery occlusion, or relative (i.e. brighter or larger objects are visible) as in a retinal detachment.
•Some diseases affecting the retina may predominantly affect one type of photoreceptor; in retinitis pigmentosa the rods are principally affected so that night vision is reduced (night blindness).

8. Degenerative diseases of the retina:
Central serous retinopathy.
Macular hole and membrane.
Age-related macular degeneration.
Retinal detachment.

9. Degenerative diseases of the retina:
Central serous retinopathy
Definition: serous retinal detachment at the macula or in the perimacular region due to a defect in the pigment epithelium 
Pathophysiology: ****** normally retinal pigment epithelium pump fluid toward outside … in CSR there is reversible pumping of fluid toward sub retinal space . Mostly ass. With stress and adrenalin

10. Mostly affects men 20–45 years of age
Degenerative diseases of the retina:
Central serous retinopathy
Etiology:
Unknown
Glucocorticoids and an increase in the diastolic blood pressure are possible risk factors.
Stress-related
Epidemiology:
Mostly affects men 20–45 years of age

11. Metamorphopsia (distorted vision)>>images
Degenerative diseases of the retina:
Central serous retinopathy
Clinical features:
Hyperopia
Metamorphopsia (distorted vision)>>images
Patients perceive images as smaller than they are
Relative scotoma: (perception of a gray area or shadow in the central field of vision)

12. Character of patient with CSR …. IMPORTANT
1- TYPE A 1 personality .. Stressful life
2- on cortisone or with Cushing syndrome .
Organ transplant at risk of csf b/c of steroid and stress esp. heart transplant

13. Ophthalmoscopy: roundish detachment of the central retina.
Degenerative diseases of the retina:
Central serous retinopathy
Diagnostics:
Ophthalmoscopy: roundish detachment of the central retina.
Fluorescein angiography.
Optical coherence tomography (OCT).
Ophthalmoscopy is the preferred diagnostic method for identifying retinal
 diseases, but depending on the suspected disorder, other methods such as fluorescein angiography
 and optical coherence tomography (OCT) may be appropriate
Acute central serous retinopathy
Fundoscopic image
The macula is elevated and a halo-like reflex can be seen.

14. Often heals spontaneously Stress reduction Rarely: laser coagulation
Degenerative diseases of the retina:
Central serous retinopathy
Treatment:
Often heals spontaneously
Stress reduction
Rarely: laser coagulation
Examination reveals a dome - shaped elevation of the retina.

15. It is classified into two major forms: dry AMD and wet AMD.
Degenerative diseases of the retina:
3. Age related macular degeneration:
Age-related macular degeneration (AMD) is a degenerative disease of the retina and represents the most common cause of blindness in individuals > 65 years in developed countries.
It is classified into two major forms: dry AMD and wet AMD.
Dry AMD is caused by deposition of various metabolites under the retinal
 pigment epithelium (drusen) and usually develops over decades.
While wet AMD is caused by neovascularizations growing into the subretinal space and manifests within weeks to months or even acutely.

16. Family history and genetic predisposition Cardiovascular disease
Degenerative diseases of the retina:
3. Age related macular degeneration:
Etiology
Multifactorial 
Risk factors
Advanced age
Family history and genetic predisposition 
Cardiovascular disease 
Smoking 
Obesity
Smokers have an up to four times higher risk of occurrence (compared to nonsmokers) and are also more likely to experience disease progression and bilateral affliction.

17. Degenerative diseases of the retina:
3. Age related macular degeneration:
Pathophysiology
Dry AMD (∼ 90%): Also termed nonexudative AMD or atrophic AMD:
 deposition of yellow-whitish material (i.e., consists of lipids, vitronectin, proteins) in and under the retinal pigment epithelium(drusen) 
 → slow progressive atrophy of the local retinal pigment epithelium (centrally or pericentrally) 
Wet AMD (∼ 10%): Also termed exudative AMD or neovascular AMD
: choroidal neovascularization (between the retinal pigment epithelium and Bruch's membrane) → leaking of intravascular serous fluid and blood 
 → sudden localized elevation of the macula and/or detachment of the retinal
pigment 

21. Clinical features *Painless central or pericentral visual impairment
Degenerative diseases of the retina:
3. Age related macular degeneration:
Clinical features
*Painless central or pericentral visual impairment 
→ reduced visual acuity, difficulty adapting to changes in lighting.
Dry AMD: slow progressive visual impairment (usually over decades) and unilateral or bilateral onset. 
Wet AMD: acute or insidious onset (over weeks to months) and usually manifests in one eye first.
*Metamorphopsia: Common and early sign in wet AMD. Possible in dry AMD, but usually not as prominent.
*Scotoma (blind spot): Late sign in dry AMD, early sign in wet AMD. Gradually increases in size, but eventually stabilizes.

22. Diagnostics *Amsler grid: detectionof metamorphopsias and scotomas
Degenerative diseases of the retina:
3. Age related macular degeneration:
Diagnostics
*Amsler grid: detectionof metamorphopsias and scotomas
*Fundoscopy.
The Amsler grid consists of a grid of straight lines with a dot at its center. The patient is asked to look at the central spot (at normal reading distance) with one eye closed. If there is metamorphopsia, the lines appear distorted or wavy. If there are scotomas, parts of the lines appear to be missing.

23. Degenerative diseases of the retina:
3. Age related macular degeneration:
The eyes of a healthy individual perceive a grid of straight lines when looking at the Amsler grid. If there is advanced macular degeneration or macular edema in AMD, the lines appear distorted or wavy (metamorphopsia). A central scotoma may also occur.

24. Fundoscopic image of the eye
Degenerative diseases of the retina:
3. Age related macular degeneration:
Fundoscopic image of the eye
A large, sharply demarcated bright area (green overlay) is visible in the macular region, indicating retinal pigment epithelium atrophy. Small punctate and patchy yellow areas or drusen (examples marked blue) can also be seen.
This is wet or dry AMD ?

25. Degenerative diseases of the retina:
3. Age related macular degeneration:
rThere are yellow plaques, or drusen, in the macula (M). Drusen are localized deposits of lipid-rich material (phospholipids, neutral fats) located under the pigment epithelium.

26. Treatment Degenerative diseases of the retina:
3. Age related macular degeneration:
Treatment
No causal treatment available (Goal of management is to slow or prevent disease progression.)
Supportive treatment
Patient education (E.g., instructions on self-monitoring using the Amsler grid.)
Visual and reading aids: magnifying glass
Avoid risk factors (e.g., cessation of smoking)
Improve diet (i.e., high in green leafy vegetables and fish)
Antioxidants therapy: vitamins A, C, and E, beta-carotene, zinc 
Treatment of Wet AMD
First-line: injection of VEGF inhibitors (Vascular endothelial growth factor INHIBITORS)
Second-line: when VEGF is contraindicated:
 Laser coagulation: direct thermal coagulation of  NEOVASCULARIZATION. 

27. Vitreous floaters and posterior vitreous detachment:
•With ageing, the vitreous gel undergoes degenerative changes over the age of 60 (earlier in myopes), with liquefaction and the formation of fragments of condensed vitreous They cast shadows on the retina, giving rise to the common symptom of vitreous ‘ floaters ’ (black moving spots)
Sometimes, in older patients or myopes, the vitreous gel collapses and separates from points of retinal attachment, a condition termed a posterior vitreous detachment.
This gives rise to acute symptoms of:
• photopsia (flashing lights) – due to traction on the peripheral retina by the detaching vitreous;
• a shower of floaters – representing condensations within the collapsed vitreous, or sometimes a vitreous haemorrhage caused when the detaching vitreous ruptures a small blood vessel during the formation of a retinal tear or hole.

28. Degenerative diseases of the retina:
4. RETINAL DETACHMENT:
Retinal detachment refers to the detachment of the inner layer of the retina (neurosensory retina) from the retinal pigment epithelium.
It is an ophthalmic emergency requiring urgent diagnosis and treatment.
Pathogenesis The potential space between the neuroretina and its pigment epithelium corresponds to the cavity of the embryonic optic vesicle. The two tissues are loosely attached in the mature eye and may become separated:
• If a tear occurs in the retina, allowing liquefied vitreous to gain entry to the sub - retinal space. This causes a progressive, rhegmatogenous, retinal detachment which may be partial or total.
• If it is pulled off by contracting fibrous tissue on the retinal surface, e.g. in the proliferative retinopathy of diabetes mellitus ( traction retinal detachment ).
• When, rarely, fluid accumulates in the sub - retinal space as a result of an exudative process, which may occur with retinal tumours or during toxaemia of pregnancy ( exudative retinal detachment ).

29. Degenerative diseases of the retina:
4. RETINAL DETACHMENT:
The most frequent causes of retinal detachment are tears or holes in the retinal pigment epithelium (rhegmatogenous detachment), risk factors for which include , previous intraocular surgery, trauma, and/or posterior vitreous detachment.

30. •have experienced a detached retina in the fellow eye;
Degenerative diseases of the retina:
4. RETINAL DETACHMENT:
Epidemiology
About 1 in of the normal population will suffer a rhegmatogenous retinal detachment. The risk is greater in patients who:
•are high myopes;
•have undergone cataract surgery, particularly if this was complicated by vitreous loss;
•have experienced a detached retina in the fellow eye;
•have been subjected to recent severe eye trauma.

31. Progression may be rapid when a superior detachment is present.
Degenerative diseases of the retina:
4. RETINAL DETACHMENT:
Symptoms
Retinal detachment may be preceded by symptoms of a posterior vitreous detachment, including floaters and flashing lights. With the onset of the retinal detachment itself the patient notices the progressive development of a field defect, often described as a ‘shadow ’ or ‘curtain’ .
Progression may be rapid when a superior detachment is present.
If the macula becomes detached there is a marked fall in visual acuity.

32. MOST COMMON CAUSE OF TRACTIONAL retinal detachment is
MOST COMMON CAUSE OF TRACTIONAL retinal detachment is .. Fibrosis in diabetic retinopathy
Causes of exudative retinal detachment ..
1-toxemia
2-tumor
3-hypertensive retinopathy

33. Degenerative diseases of the retina: 4. RETINAL DETACHMENT:
Type of retinal
 detachment
Rhegmatogenous retinal
 detachment 
Non-rhegmatogenous retinal
Tractional retinal
Exudative
 retinal
Mechanism
Most common type
Retinal
 tears → retinal
 fluid, which is formed by vitreous
 degeneration, seeps into the subretinal space → retinal
Formation of vitreoretinal bands 
 → traction on the vitreoretinal band during eye movements or as a result of sudden decrease in intraocular pressure
 → retinal
Subretinal fluid accumulation without retinal
 tears
Tumor growth

34. Degenerative diseases of the retina: 4. RETINAL DETACHMENT:
Type of retinal
 detachment
Rhegmatogenous retinal
 detachment 
Non-rhegmatogenous retinal
Tractional retinal
Exudative
 retinal
Risk factors
Pathological myopia
Previous intraocular surgery (e.g., cataract
 surgery) 
Posterior vitreous detachment
Trauma
Retinal
 detachment of the other eye 
Peripheral retinal
 breaks
Lattice degeneration 
Retinoschisis
CMV retinitis
Family history of retinal
 detachment
Proliferative diabetic retinopathy
Retinopathy of prematurity
Sickle cell
 retinopathy
Systemic diseases
Pre-eclampsia
Hypertension
Bleeding disorders
Polyarteritis nodosa
Ocular diseases
Sudden decrease in intra-ocular pressure due to perforating injuries or intraocular surgery
Retinoblastoma
Malignant melanoma
 of 

35. Degenerative diseases of the retina: 4. RETINAL DETACHMENT:
Clinical features:
 symptoms
*Floaters
*Flash of light (photopsia)
Localized retinal detachment: scotoma
 (visual field defect)
Depending on the location of the detachment, a rising wall/dark shadow may appear from the top to the bottom (descending curtain) or from the bottom to top.
The visual field
 defects may begin in either the nasal or temporal visual field .
Extensive retinal detachment and/or macular involvement:
Sudden, painless loss of vision in the affected eye
Relative afferent pupillary defect

36. Retinal vascular disease

37. Signs of retinal vascular disease

38. Diabetic retinopathy Epidemiol
Type I diabetes
Onset is relatively acute and diabetic retinopathy begins to appear about 5 years after onset.
Type II diabetes
retinopathy may be found at presentation because type II diabetes may be present for several years prior to diagnosis.
Diabetes is associated with the following ocular events:
retinopathy
cataract: a rare ‘ snowflake ’ cataract in youth, and a greater frequency and earlier onset of age - related cataract;
glaucoma (e.g. rubeotic glaucoma, but an association with chronic open angle glaucoma is disputed);
extraocular muscle palsy due to microvascular disease of the third, fourth or sixth cranial nerves.

39. Pathology
Factors thought to be important in the development of diabetic retinopathy include:
duration of diabetes: 80% have retinopathy after 20 years of disease;
poor diabetic control;
coexisting diseases, particularly hypertension;
smoking.
the development of retinopathy may also be accelerated by pregnancy, and patients require careful screening.
Retinal damage results from damage to the circulation. Pathological studies show:
a decrease in the number of pericytes surrounding the capillary endothelium;
development of microaneurysms on the capillary network, which allow plasma to leak out into the retina;
patchy closure of the capillary net, (capillary non-perfusion), resulting in areas of ischaemic retina and the development of arteriovenous shunts.

40. History
Diabetic retinopathy should be diagnosed before it is symptomatic. All diabetics should have fundoscopy performed at least yearly. Screening for sight - threatening retinopathy (maculopathy and proliferative retinopathy) should begin by 5 years after diagnosis in patients with type I disease, and may be from the time of presentation in type II disease, since its time of onset is unknown. Visual acuity may be reduced gradually by a maculopathy, or suddenly by a vitreous haemorrhage.
Treatment
The mainstay of treatment for sight - threatening diabetic retinopathy is laser therapy.
The development of vitreous haemorrhage which does not clear after a few weeks, or fibrous traction on the retina causing detachment from the overlying pigment epithelium (traction retinal detachment), may require surgical treatment. A vitrectomy is performed to remove the vitreous gel and blood and to repair any of the detached retina.

41. diabetic retinopathy classification
NPDR
PDR
NPDR 4 stages
Mild bleeding in 1 quadrant
Moderate  bleeding in 2 quadrant
Sever bleeding in 3 quadrant
Sever
(pre-proliferative) 
Bleeding in 4 quadrant
Small bleeding
and bleeding

42. Arterial occlusion Pathogenesis…
Central and branch retinal artery occlusions are usually embolic in origin.
Three types of emboli are recognized:
fibrin – platelet emboli, commonly from diseased carotid arteries;
cholesterol emboli, commonly from diseased carotid arteries (Figure 12.5 );
calcific emboli, from diseased heart valves.

43. History
The patient complains of a sudden painless loss of all or part of the vision.
Fibrin – platelet emboli typically cause a fleeting loss of vision as the emboli pass through the retinal circulation (amaurosis fugaxظلام عابر). This may last for some minutes, and then it clears.
Cholesterol and calcific emboli may result in permanent obstruction with no recovery in vision (they may also be seen in the retinal vessels of asymptomatic individuals).
In young patients, transient loss of vision may be caused by migraine.
Signs
Occasionally, a series of white platelet emboli can be seen passing rapidly through a vessel; more often a bright yellow, reflective cholesterol embolus is noted occluding an arterial branch point. The acutely affected retina is swollen and white (oedematous), while the fovea is red (cherry - red spot) because the choroid can be seen through the thin retina of the fovea. After several weeks the disc becomes pale (atrophic) and the arterioles attenuated.
The condition may also occasionally be caused by vasculitis, such as giant cell arteritis.

44. Investigation
Patients require a careful vascular work - up, since disease in the eye may reflect systemic vascular disease. A search for carotid artery disease should be made by assessing the strength of carotid pulsation and listening for bruits. Ischaemic heart disease, peripheral claudication and HTN may present.
Treatment
Acute treatment of central and branch artery occlusions is aimed at dilating the arteriole to permit the embolus to pass more distally and limit the damage.
The patient is referred to an eye unit, where the following measures may be tried:…
lowering the intraocular pressure with intravenous acetazolamide;
ocular massage;
paracentesis (a needle is inserted into the anterior chamber to release aqueous and lower the intraocular pressure rapidly);
asking the patient to rebreathe into a paper bag firmly applied around the mouth and nose to use the vasodilatatory effect of raised carbon dioxide levels.
Prognosis
Full visual recovery occurs with amaurosis fugax, but more prolonged arterial occlusion results in severe, unrecoverable visual loss.

45. Venous occlusion History Pathogenesis Signs
Central retinal vein occlusion (CRVO) may result from:
abnormality of the blood itself (the hyperviscosity syndromes and abnormalities in coagulation);
an abnormality of the venous wall (inflammation);
an increased ocular pressure.
History
The patient complains of a sudden partial or complete loss of vision, although onset may be less acute than that of arterial occlusion.
Signs
There is marked haemorrhage and great tortuosity and swelling of the veins.
The optic disc appears swollen. Branch retinal vein occlusion may originate at the crossing point of an arteriole and a vein where the arteriole has been affected by arteriosclerosis associated with hypertension (A/V nipping).
Subsequently:
Abnormal new vessels may grow on the retina and optic disc, causing vitreous haemorrhage. This happens if the retina has become ischaemic as a result of the vein occlusion (an ischaemic retinal vein occlusion).
In ischaemic retinal vein occlusion abnormal new vessels may grow on the iris, causing rubeotic glaucoma.

47. Prognosis Investigation Treatment
Investigation of a CRVO includes vascular and haematological work - up to exclude increased blood viscosity. CRVO is also associated with raised ocular pressure, diabetes and hypertension and smoking.
Treatment
Retinal laser treatment is given if the retina is ischaemic, to prevent the development of retinal and iris new vessels may improve vision by reducing macular oedema which may also be treated with intravitreal steroid therapy.
There is also increasing interest in the use of anti-VEGF agents.
Prognosis
The vision is usually severely affected in central, and often in branch, vein occlusion and usually does not improve. Younger patients may fare better, and there may well be some visual improvement.

48. Arteriosclerosis and hypertension stages of hypertensive retinopathy
Arteriosclerosis can be visualized in the eye as an attenuation of the retinal arterial vessels (sometimes referred to as copper and silver wiring (first stage)) and by the presence of nipping (second stage) of the retinal vein where it is crossed by an arteriole.
If severe, the retina may also demonstrate signs of capillary occlusion (cotton - wool spots) (third stage). Very high blood pressure may, in addition, cause swelling of the optic nerve head – papilledema- (fourth stage).
Hypertension in addition may cause focal arteriolar narrowing and a breakdown in the blood – retinal barrier, resulting in the signs of vascular leakage (haemorrhage and exudate). These are particularly prominent if the hypertensionis of renal origin.
The patient may complain of blurring of vision and of episodes of temporary visual loss, although severe retinopathy may also be asymptomatic.

49. Treatment of the hypertension results in the resolution of the retinal signs over some months. A rapid reduction of systemic blood pressure is avoided, because it may precipitate vascular occlusion.

50. Retinopathy of prematurity
Retinopathy of prematurity is a vascular response of the retina occurring predominantly in low-birth weight premature infants exposed to oxygen therapy in the early weeks of life.

51. Roth spots (haemorrhages have white centres) can be caused by Leukaemia with a greatly raised white cell count. These may also be a feature of bacterial endocarditis and autoimmune diseases associated with vasculitis.

52. Thank you