Chronic visual loss cc.docx - hind.ccDocument Transcript
BAYAN MAMDOHGirls work from <br />Dr.Sameer jamal lectures records<br />2010 <br />Chronic visual loss.<br />Just to remained you :<br />History is very important not just in ophthalmology but in every branch in medicine always ask:<br />
When, what, where & how?
what-> to know the problem
where -> to know the location
when & how ->they give an idea about the pathology
Precipitating factors & relieving factors?
Precipitating & relieving factors ->to know how to treat this pathology.
Association -> give an idea about the pathology.
Analyze all the symptoms because every question means something.
The most important question the Dr. asks in the clinical practice is AGE OF THE PATIENT? <br />Always write the age of the patient because diseases occur in categories (children, adults & elderly).<br />Visual loss.<br />Acute: usually due to trauma or ischemia.<br />Subacute: from inflammation or infection.<br />Chronic: hereditary, degenerative & multi-factorial.<br />Chronic visual loss (CVL): defined as that the disease has started & still going on (4-6 weeks) from it's onset.<br />Vision loss: vision is :<br />
loss : not total loss maybe mild or severe Visual Loss.<br />Causes of Chronic visual loss or disturbance:<br />
RE in the most common one.
Media problems (cornea, lens & vitreous)
Optic nerve diseases
Visual pathway diseases
RE: Myopia, hyperopia & stigmatism.
Media diseases: as abnormal shape of the cornea " keratoconus " ->hereditary disease.
redness is a sign of acute problem, chronic problems has no redness.
If the opacity at the surface of the cornea we will not see behind it "pupil" that if we look through the opacity. but if the pathology in the lens we will be able to see the pupil.
Despite he has opacity but because there is redness so it's an acute problem -> corneal ulcer.
Corneal opacity: no redness in the sclera with opacity over the cornea.
Lens opacity: clearly can visualize the pupil.
this is an eye with cataract.
When the area of the pupil turns white quot;
not in front the pupil but the pupil itselfquot;
-> Leukocoria <br />
Differential diagnosis of white pupil "Leukocoria":
Retinoblastoma >>>>>>> .
Retinopathy - prematurity.
Retinal detachment>>>>>> .
Important in OSPE: what's the name of the physical finding & what are the differential diagnosis?
CVL due to causes related to causes related to the lens:
Cataract: is defined as opacity of the lens. & it's either congenital or acquired.
post-infection or post-inflammation.
Metabolic disorders as DM.
Cataract is the leading cause of treatable blindness in all countries of the world.
Prevalence in Asian countries (0.3-4%)
Lens subluxation is a cause of CVL.
We mustn't see the zonules that attached to the lens, & here lens is shifted up-word.
Patient will not be able to see because when the position of the lens change lead to myopia or astigmatism because it's subluxed not equal -> CVL.
When the lens is away from the visual axis (drops interior or drops posterior) -> Hyperopia will occur.
Examples of different Causes of mal-position of the lens:
Trauma to the eye.
Important Causes for CVL :<br />
GLUCOMA : it's an optic neuropathy, associated with increase intraocular pressure in the eye. اعتلال العصب البصري <br />Any ball that contains air or fluid inside has a pressure & so do the eye.<br />The problem with glaucoma is in the optic nerve -> the majority of the cases have ↑IOP but some cases have a normal pressure or even subnormal IOP.<br />Signs of High Pressure Glaucoma:<br />
High IOP. Normally (10-21)
Large cup Normally (0.2-0.3) if >0.3 consider to be abnormal "as the picture above there is ↑ Cupping & optic atrophy".
What's a physiological cup? <br />
It's an area devoid of nerve tissue.
No nerve tissue ->No blood vessels ->so appears white "sclera from behind"
All nerve fibers are red, nerve fibers come out of the retina & form the optic nerve. Normal Disc.
When optic nerve fibers die in glaucoma they die from the inner side & lead to enlargement of the cup. "cup will enlarge because nerve fibers surrounding it is dyeing" Cupping & atrophy of the optic nerve.
The 3 criteria in glaucoma: ( to diagnose a patient we need 2 out of 3)<br />
Visual field defects
Characteristic visual field defect of glaucoma is ARCUATE SCOTOMA زي القوس
GP don't deal with or treat glaucoma but if there is increase cupping we have to refer the patient.
Any Patient > 40 years male or female routinely need to be checked ANNUALY for glaucoma, because glaucoma is a symptomless disease & patients complaint very late.
Risk factors for glaucoma:
Age >40 years.
Family history which is the most important.
Both patient must check annually because glaucoma is the most common optic neuropathy, affects the optic nerve leading to irreversible damage & total blindness so we need to diagnose it as early as possible. اللي يرح من عصب العين ما يرجع
Prevalence: about 0.74 -> almost 1 % in general population.<br />After the age of 40 years prevalence will start to increase year by year.<br />Glaucoma can be classified as:<br />
Congenital Vs Acquired.
Open angle Vs closed angle.
Primary Vs secondary.
Congenital glaucoma (CG) : it's a different story.<br />Has a specific features & as a GP we have to know the signs of CG.<br />Congenital means: the child born with it or appears early in the 1st 6 months of life.<br />We have to be aware for the physical signs : <br />
Big eyes (bufthalmus): زي عين البقر و كل ما كبرت العين كل ما كان المرض أكبر
In congenital glaucoma pressure increase -> & children's eyes have the ability to enlarge up to 3 years but after that the size of the eyes will not change
1st thing to think about in a neonate with big eyes is -> glaucoma.
Big cornea: if lifted untreated may lead to corneal opacities " not able to see the pupil because cornea is not clear"
Symptoms of glaucoma: <br />
Photophobia in an infant is congenital glaucoma until proven otherwise. ما يداني النور لما نحطو عند الشباك يقلب وجهه و لما يخرج الشارع يغمض عينه
We have to rule out CG in any photophobic child particularly infants.<br />
Watering in infants either: CG or nasolacrimal duct obstruction <<< common.
So always think about CG because it's a very serious & blinding disease.
If GP are not aware for Signs & Symptoms of CG ->patient will get worse & by the time ophthalmologist see the patient his vision will be already gone.
Causes of loss of vision in CG:
Pressure on the optic nerve-> will press on the optic nerve & cause loss of nerve fibers.
Saudi Arabia has the highest prevalence of CG in the world No.1 due to consanguinity.
The most important disease in the retina lead to CVL is Diabetic Retinopathy.
DM is worse in our country because they don't go for ophthalmologist asking for advice or checking on their eyes but they depend on the physician.
DM affecting the eyes is a matter of time, because it's a microvascular disease affects every structure in the body -> the worst to be affected are the eyes & kidneys.
The eyes affected severely & significantly before the patient come & complain of any symptom.
When the patient come with symptoms usually it's already too late because of that our Role as a GP is to refer any DM patient once diagnosed to an ophthalmologist because this DM maybe started long time ago & just discovered now.
After that ophthalmologist will decide when this patient will need to be seen again:
Usually every year if no changes detected but once there are changes in the retina this patient will need to be followed up every 6 months.
DM patients must be referred to an ophthalmologist wither they have type I or type II DM.
DM changes: <br />
Background DM retinopathy.
Pre-Proliferative DM retinopathy.
Proliferative DM retinopathy. تكاثر الشبكيه
Background DM retinopathy consists of:
Microanyurism & hemorrhages
GP will not see the Microanyurism, so we will look for hemorrhages & hard exudates.
Further worse stage is Pre-Proliferative DM retinopathy which consists of:
Soft exudates -> an indication of retinal ischemia.
How to differentiate soft from hard exudates ?
Hard exudates -> more yellowish, refractive deposit, deep inside the retina, circular & irregular in shape.
Soft exudates -> usually flam shape & superficial.
With further more severe ischemia for the retina we will have Proliferative retinopathy:
Abnormal blood vessels that cause 2 things:
Edema because it leaks.
Hemorrhages ( on the retina -> pink hemorrhage, or inside the eye -> vitreous hemorrhage)
If we left this untreated the abnormal blood vessels will regress with time & become fibrotic & pull the retina leading to TRACTIONAL retinal detachment. >>> Tractional because it's pulling the retina.
DM is an important cause for blindness all over the world & it's common in KSA, so we must refer the patient to an ophthalmologist.
If the patient has new blood vessels formation but still the vision is not affected so treat him with laser.
What's the idea of laser?
Laser kills the periphery of the retina to favor the central part of the retina which is responsible for vision.
By killing part of the retina the nutrients will be enough to the rest of the retina.
Because ischemia is so severe & so bad we kill the periphery of the retina so central part can survive. المريض حينعمي في أطراف عينه
Visual field will disturb & the patient will not be able to see in the dark because periphery of the retina responsible for dark vision while central vision is maintained.
Other disease of the retina causing CVL:
Post-trauma to the retina.
"all are Post-… because if 6 weeks pass on this event it will change from ACL to CVL"
Retinal disorders as hypovitaminosis A may lead to CVL in the periphery initially "it's an important cause for CVL in certain parts of the world.
Retinal dystrophy as:
Retinitis pimentosa "which is a black spots all over the retina, it's a hereditary disorder of the retina, the patient lose receptors in the retina & eventually become blind, we can't do anything for those patients, it's common in KSA due to consanguinity"
Age related macular degeneration(ARMD): common in western countries.
Optic Nerve Diseases:
White optic nerve: nerve fibers are lost & no blood vessels -> (Cup = 0.5)
The hall mark of optic atrophy is white or yellowish optic nerve.
Pink optic nerve: normal.
Optic atrophy is a common pathway to all optic nerve diseases.
The most important cause for Optic atrophy is Glaucoma because it's the most common optic neuropathy.
Increase optic nerve swelling due to increase IOP will lead to optic nerve swelling at the beginning, but if left untreated the high IOP will affect the nerve & patient will lose vision in (4-6 weeks) & become totally blind.
Any Patient with high IOP should be referred to an ophthalmologist to be sure that optic nerve swelling subsides with no atrophy.
Chronic papilledema: it could be hereditary or compressive not only ischemic, old neuritis or glaucoma.
Mechanism of chronic illnesses:
Congenital anomalies in optic nerve lead to CVL:<br />
Small optic nerve: retina & part of the optic nerve is missing (Coloboma of the optic nerve) ->part of the optic nerve is missing choroid also may be missing.
Optic nerve may be compressed in chronic illnesses as:
Thyroid -> it affects the muscles & the optic nerve too "because muscles present in the orbit so if there is any swelling in the muscles will lead to compression over the optic nerve.
Other causes: optic nerve maybe involved by tumors of the optic nerve as: (optic nerve Glioma, optic nerve meningioma).
Chronic diseases in the visual pathway:
Compressive -> tumors.
Old acute insult -> (vascular problem lead to AVL but after 6 weeks it become CVL)
Picture: MRI of the brain showing (Mickey mouse) slice -> so we are at the level of the mid-veins, where optic chiasm present.
MRI showing pituitary tumor sitting at the chiasm ->causing CVL.
The most important cause of CVL in children & adult is AMBLYOPIA. العين الكسلى أو كسل العين
It's No.1 cause of CVL in children.
It's a significant problem among patients.
Definition: it's a unilateral or bilateral potentially reversible visual loss due to a pathological visual experience that occurs during the critical period of visual development.
Visual loss: not necessary to be totally blind, but there is a significant poor vision (most of the time -> moderately poor)
Abnormal visual experience: all children when they born they have poor vision but it starts to develop & continue to develop up to 12 years.
If any problem happen to the eye as:
Ptosis.-> prevent light to go to inside the eye.
Anisometropia. اختلاف نمرة النظارة من اليمين لليسار
( all those causes may lead to arrest of the development of child's vision, because he is not born with 6/6 acuity but a poor vision which need development but there is pathological obstacles)
The most common pathological obstacle lead to amblyopia is SQUIT. -> No. 1 then Anisometropia comes after.
Critical period of visual development from ( 0-12 years) & the most important period is the first month of his life. كل ما كبر نبعد عن شرح الأمبليوبيا وكل ما صغر نقرب من شرح الأمبيليوبيا
before we discharge any child from nursery we have to make sure that he has nothing that prevents his vision from developing As:
How to exclude those conditions ?
CG: by inspection the eyes.
Cataract & RE by Red Retinal Reflex Test -> stand in front of the patient, at the level of the patient, about 1 meter from the patient, shine the light on in a dam room, place the cushion of the ophthalmoscope over your nose or eye brow, look through the ophthalmoscope & look at both eyes at the same time for the reflexion of light coming from the eye-> will see the reflex (orange color) -> Normally.
The quality of the Orange color is different in People wearing eye glasses.
Red Retinal Reflex test telling if:
Media has opacities preventing vision development or not.
Picture: showing nonsymmetrical RRR on both sides, one is a little bet white, the other eye is pink with some white area.
Any whitening of the color named Leukocoria -> white pupil -> serious sign in children & adult:
Adult not as serious as in children because their vision is already developed.
In children Leukocoria is very important & it means one of the following:
Congenital cataract. >>
Retinopathy & prematurity.
Retinoblastoma is a tumor of the retina, peak of it is at 2 years of age.
Any patient present with Leukocoria will not be diagnosed if we didn't use the ophthalmoscope.
Why do we care all that much to detect those infants early?
Because if a child present with congenital cataract we do the operation within 1 week from the time of diagnosis, so this child will have a better chance for development of his vision. BUT if the patient present late (beyond 6 months) we will do the cataract surgery but practically this child is blind.
We have a very small window, we operate within this window to safe vision development ->this window is 6 weeks time, we operate as early as possible during this period of time.
The only thing that prevents us from doing the operation if the child is sick but if he is fine even if he is just 1 week , we do the surgery for him.
The window is:
6 weeks Maximum if unilateral cataract.
3 months if bilateral cataract ->we do cataract surgery "because if we leave cataract inside the eye it will cause lots of problems" but vision will not be good.
Causes of AMBLYOPIA:
Sensory deprivation (Cataract, glaucoma, ptosis & medical opacities).
Our Rule As a GP
Detection & suspicion.
We have to educate the patient before referring him to any other Doctor not to lose the patient & to let this patient get the right surfaces "If you don't know about this patient's condition don't Talk to him"
Refer for something: (i.e.: If cataract urgent referral, not emergency but very high urgency)
Our Rule in CVL in adult: quot;
children are special casequot;
GP must know how to test visual acuity for everyone, if not 6/6 should be referred..
If sudden, acute or subacute -> this is an emergency but if chronic, long standing -> it's not an emergency but we have to know is it refractive or organic:
Refractive By MPH -> Refer to ophthalmologist or optometrist.
Organic -> refer to ophthalmologist.
Another test the GP must do is the Red Retinal Reflex test, because it tells about:
High refractive errors.
Referral of any child with corneal opacity, large cornea or Globe & photophobia to an ophthalmologist.
Our Rule in management of Glaucoma patients:<br />
Diagnosis of acute angle closer glaucoma: (AACG)
It's different from chronic, here they have crowded angle & for a reason this angle closes suddenly , the pupil gets dilated, the pressure rises up & they come with: (AVL, Pain & redness) -> Pupil is Dilated on examination.
Iritis also present with (AVL, Pain & Redness) -> but when you examine the pupil it's Small.
(Schultz's Tonometer) : to diagnose AACG -> Apply local anesthetic on the eye, then place this instrument over the cornea, According to the pressure the spine will move -> we will take the reading & see it on the Schultz's Tonometer r Table.
Schultz's should be available in every emergency room.
Treatment Initiation: "Call the ophthalmologist"
Acute ↑ pressure -> press over the patient's eye intermittently for (5-10 sec.) then take your hand off.
Give something to lower IOP as -> Diamox I.V., Carbonic anhydrase inhibitor.
Our Rule in Optic Nerve diseases:<br />
any patient with VL we don't know is it organic or not, so we suspect Optic Nerve involvement.
Do visual field confrontation -> if abnormal so it tells you that it's a neurological problem (either optic Nerve or visual pathway).
Pupil examination -> normal pupil doesn't tell anything but abnormal tells that it's an optic nerve disease or any visual pathway disease.
Funds examination: -> tells if the patient has optic atrophy, Glaucoma or optic nerve swelling.
Pictures: showing examples of optic nerve swelling<br />Optic nerve swelling- optic nerve atrophy & optic nerve cupping -> All Are IMP.<br />Our Rule in retinal diseases:<br />Suspicion.- the same tool – refer the patient.<br />Our Rule in Visual Pathway Diseases:<br />Suspicion.<br />Uses of Ophthalmoscope: <br />