Soft Contact Lens Material.pptx
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Soft contact lenses are made of hydroxyethyl methacrylate (HEMA), which was developed by Wichterle and Lim. HEMA contains a polar OH group that allows water to bind. Contact lenses can have water contents ranging from 38-80%, with lower water content lenses being more stable and easier to handle, and higher water content lenses having greater oxygen permeability but being less stable. Lenses can also be ionic or non-ionic, with ionic lenses being more deposit-prone but better wettable, and non-ionic lenses being less deposit-prone but less wettable. The FDA classifies soft contact lenses into four groups based on water content and ionicity. A lens's Dk, or
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ACCOMMODATIVE ESOTROPIA.pptx............
Accommodative Esotropia
Definition
Esotropia (ET) linked to accommodation
History
Onset 6 months - 7 years (average 2.5 years)
May be intermittent at onset, (sometimes precipitated by trauma or illness) becoming constant
Diplopia may occur but usually disappears as the patient develops suppression scotoma
Approximately 75% have a family history
Amblyopia common (50%)
No associated IOOA or DVDs
Classification
Accommodative
High AC / A
Mixed (most common)
Definition
Hypermetropia means that a high amount of accommodation (with a proportionate amount of convergence) is required to focus even on a distant target
Accommodation is associated with a dis-proportionately high amount of convergence
Hypermetropia
High AC / A
1.Fully accommodative
Esotropia (ET) fully corrected by full cycloplegic refraction
2. Partially / (Non)
accommodative
ET only partially corrected by full cycloplegic refraction (i.e. still ET for D&N)
Distance prescription corrects distance deviation but a deviation remains at near
CTD / N
ET Distance= ET Near (within 8Δ)
Straight Distance (after correction), ET Near.
ET for near may be reduced or eliminated by a +3.0 add
ET Distance < ET Near (by >8Δ)
i.e. When straight for distance with full cycloplegic correction will still have ET for near.
ET for near may be reduced or eliminated by a +3.0 add
Refraction
Hypermetropia (e.g. +3 to +10D)
Emmetropia (ranges from myopic to high hyperope)
Hypermetropia
AC / A ratio
Normal (e.g. 3-5)
High
High
Examination Structure
1. Visual Acuity (Best Corrected)
Amblyopia is common (50%, especially partially accommodative)
2. Spectacles
3. Inspection
Abnormal Head Position (AHP)?
Hirschberg (pupil margin=30Δ, limbus=90Δ) - Esotropia
(Lids normal)
(Pupils normal)
4. Cover-Testing
Comitant ET (Measure distance & near as an estimation of AC / A. An ET that is greater for near than distance suggests a high AC / A, but this can only be proven by formal testing- see below)
A) Without glasses: CTD, CTN
B) With glasses: CTD, CTN
(NB: Attempts may also be made to measure the AC / A ratio by the lens gradient method by cover-testing at near with and without +3D lenses)
5. Ocular Rotations
Full ductions (Exclude CNVI palsy) ± IOOA
DVD is uncommon
6. Stereopsis
7. Dilated Fundoscopy
8. Cycloplegic Refraction
Often Hypermetropic. Use:
Cyclopentolate 1%, (Phenylephrine 2.5%) or
Atropine 1% bd for 3 days prior if dark irides, amblyopic, unsure, unco-operative
Summary
Fully / Partially / Non-Accommodative ET with presumed Normal / High AC / A
Investigations
Most accommodative esotropias do not require further investigations. However, neuroimaging (MRI brain) should be considered when the presentation is atypical:
Acute onset
Older (>7yrs)
Incomitant i.e. abduction deficit
Diplopia, other neurological signs (e.g. CN VI, papilloedema, nystagmus)
No hypermetropia
STRABISMUS EXAMINATION.pptx.............
Eye Movements Examination
Examination Structure
Sit on the right of the patient, your eyes and the patient’s eyes should be at the same level
Speak whilst examining
Ask children their age
Look around the room for clues – spectacles, parents (for inherited syndromes)
1. Visual Acuity (Best Corrected)
The worse eye is usually the affected one (may be amblyopic)
2. Spectacles
It is easiest to estimate the script of spectacles by comparing the image of a line viewed through the lens and just around it. A distance line such as a doorway is perfect for this purpose.
Hand Neutralise
Minus lens → “With” movement
Plus lens → “Against” movement
Astigmatism
Ground in Prism
The image of the line through the lens has a fixed deviation away from the image of the line just around it. This cannot be compensated by moving the lens. The apex of the prism points towards the deviation.
Fresnel Prism
Method for easy check: turn spectacles side-on
BO (CNVI palsy), BD (CNIV palsy on affected eye)
3. Inspection
Have the patient fixate on a distant target- choose one line above their visual acuity
Only comment on a strabismus if it is obvious (say “there appears to be an exo or eso deviation” in case the patient has a dragged macula and there is no tropia)
1. Abnormal Head Posture (AHP)
Ask patient to “Please sit up straight” and stand back to inspect
Face turn? In direction of action of paretic muscle
Chin up / down? Up in elevator paresis, Down in depressor paresis
Correct any AHP before cover tests (check for neck pathology)
2. ± Corneal Light Reflexes (Hirschberg)
Shine a pen torch into the patient’s eyes and inspect the corneal reflexes. In patients with straight eyes, they should be symmetrical and lie over the same point on the cornea. In patients with strabismus, the corneal reflex of the fixing eye will lie centrally within the pupil, and the other will be displaced (1mm of corneal decentration = 15 Δ strabismus, Pupil margin = 30 Δ, Limbus = 90 Δ). Be aware that tropias can only be definitively diagnosed with cover testing. The Hirschberg test becomes more important when vision is poor (e.g. < 6 / 60 in either eye) and cover-testing is not possible.
3. Ptosis (CNIII palsy)
4. Pupils (Anisocoria) (CNIII palsy)
5. Globe Position
Proptosis (axial vs. non-axial)
6. Other
Nystagmus, facial asymmetry, hearing aids, scars (conjunctiva- squint surgery)
7. Ask Yourself
“Could this be TED?”- proptosis, chemosis, injection, lid retraction
4. Cover-Testing
Ensure the patient can fixate “Tell me if I block your view”
If VA <6 / 60 can’t do cover! → Perform Hirschberg (corneal light reflexes) and / or Krimsky (corneal light reflexes through prism placed over the fixing eye) tests.
The patient should wear their distance (& near) spectacles (unless they have prisms!)
This helps the patient if they can’t fixate on a target uncorrected
It is crucial in accommodative esotropia to test with and without spectacles
Cover for tropia (manifest)
Uncover for phoria (latent)
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ACCOMMODATIVE ESOTROPIA.pptx............
Accommodative Esotropia
Definition
Esotropia (ET) linked to accommodation
History
Onset 6 months - 7 years (average 2.5 years)
May be intermittent at onset, (sometimes precipitated by trauma or illness) becoming constant
Diplopia may occur but usually disappears as the patient develops suppression scotoma
Approximately 75% have a family history
Amblyopia common (50%)
No associated IOOA or DVDs
Classification
Accommodative
High AC / A
Mixed (most common)
Definition
Hypermetropia means that a high amount of accommodation (with a proportionate amount of convergence) is required to focus even on a distant target
Accommodation is associated with a dis-proportionately high amount of convergence
Hypermetropia
High AC / A
1.Fully accommodative
Esotropia (ET) fully corrected by full cycloplegic refraction
2. Partially / (Non)
accommodative
ET only partially corrected by full cycloplegic refraction (i.e. still ET for D&N)
Distance prescription corrects distance deviation but a deviation remains at near
CTD / N
ET Distance= ET Near (within 8Δ)
Straight Distance (after correction), ET Near.
ET for near may be reduced or eliminated by a +3.0 add
ET Distance < ET Near (by >8Δ)
i.e. When straight for distance with full cycloplegic correction will still have ET for near.
ET for near may be reduced or eliminated by a +3.0 add
Refraction
Hypermetropia (e.g. +3 to +10D)
Emmetropia (ranges from myopic to high hyperope)
Hypermetropia
AC / A ratio
Normal (e.g. 3-5)
High
High
Examination Structure
1. Visual Acuity (Best Corrected)
Amblyopia is common (50%, especially partially accommodative)
2. Spectacles
3. Inspection
Abnormal Head Position (AHP)?
Hirschberg (pupil margin=30Δ, limbus=90Δ) - Esotropia
(Lids normal)
(Pupils normal)
4. Cover-Testing
Comitant ET (Measure distance & near as an estimation of AC / A. An ET that is greater for near than distance suggests a high AC / A, but this can only be proven by formal testing- see below)
A) Without glasses: CTD, CTN
B) With glasses: CTD, CTN
(NB: Attempts may also be made to measure the AC / A ratio by the lens gradient method by cover-testing at near with and without +3D lenses)
5. Ocular Rotations
Full ductions (Exclude CNVI palsy) ± IOOA
DVD is uncommon
6. Stereopsis
7. Dilated Fundoscopy
8. Cycloplegic Refraction
Often Hypermetropic. Use:
Cyclopentolate 1%, (Phenylephrine 2.5%) or
Atropine 1% bd for 3 days prior if dark irides, amblyopic, unsure, unco-operative
Summary
Fully / Partially / Non-Accommodative ET with presumed Normal / High AC / A
Investigations
Most accommodative esotropias do not require further investigations. However, neuroimaging (MRI brain) should be considered when the presentation is atypical:
Acute onset
Older (>7yrs)
Incomitant i.e. abduction deficit
Diplopia, other neurological signs (e.g. CN VI, papilloedema, nystagmus)
No hypermetropia
STRABISMUS EXAMINATION.pptx.............
Eye Movements Examination
Examination Structure
Sit on the right of the patient, your eyes and the patient’s eyes should be at the same level
Speak whilst examining
Ask children their age
Look around the room for clues – spectacles, parents (for inherited syndromes)
1. Visual Acuity (Best Corrected)
The worse eye is usually the affected one (may be amblyopic)
2. Spectacles
It is easiest to estimate the script of spectacles by comparing the image of a line viewed through the lens and just around it. A distance line such as a doorway is perfect for this purpose.
Hand Neutralise
Minus lens → “With” movement
Plus lens → “Against” movement
Astigmatism
Ground in Prism
The image of the line through the lens has a fixed deviation away from the image of the line just around it. This cannot be compensated by moving the lens. The apex of the prism points towards the deviation.
Fresnel Prism
Method for easy check: turn spectacles side-on
BO (CNVI palsy), BD (CNIV palsy on affected eye)
3. Inspection
Have the patient fixate on a distant target- choose one line above their visual acuity
Only comment on a strabismus if it is obvious (say “there appears to be an exo or eso deviation” in case the patient has a dragged macula and there is no tropia)
1. Abnormal Head Posture (AHP)
Ask patient to “Please sit up straight” and stand back to inspect
Face turn? In direction of action of paretic muscle
Chin up / down? Up in elevator paresis, Down in depressor paresis
Correct any AHP before cover tests (check for neck pathology)
2. ± Corneal Light Reflexes (Hirschberg)
Shine a pen torch into the patient’s eyes and inspect the corneal reflexes. In patients with straight eyes, they should be symmetrical and lie over the same point on the cornea. In patients with strabismus, the corneal reflex of the fixing eye will lie centrally within the pupil, and the other will be displaced (1mm of corneal decentration = 15 Δ strabismus, Pupil margin = 30 Δ, Limbus = 90 Δ). Be aware that tropias can only be definitively diagnosed with cover testing. The Hirschberg test becomes more important when vision is poor (e.g. < 6 / 60 in either eye) and cover-testing is not possible.
3. Ptosis (CNIII palsy)
4. Pupils (Anisocoria) (CNIII palsy)
5. Globe Position
Proptosis (axial vs. non-axial)
6. Other
Nystagmus, facial asymmetry, hearing aids, scars (conjunctiva- squint surgery)
7. Ask Yourself
“Could this be TED?”- proptosis, chemosis, injection, lid retraction
4. Cover-Testing
Ensure the patient can fixate “Tell me if I block your view”
If VA <6 / 60 can’t do cover! → Perform Hirschberg (corneal light reflexes) and / or Krimsky (corneal light reflexes through prism placed over the fixing eye) tests.
The patient should wear their distance (& near) spectacles (unless they have prisms!)
This helps the patient if they can’t fixate on a target uncorrected
It is crucial in accommodative esotropia to test with and without spectacles
Cover for tropia (manifest)
Uncover for phoria (latent)
ANTERIOR SEGMENT EXAMINATION.PPTX.......
1. Visual Acuity, IOP, Inspection, ± Refraction
Always stand back and examine the patient as a whole. Age / gender / ethnicity are often useful in narrowing the potential differential diagnoses. Iris heterochromia, symblephara, ankyloblepharon and forniceal shortening are often more obvious on gross inspection before beginning the slit lamp examination.
2. Lid, Lashes, Lacrimal Structures
Blepharitis,
Ectropion / entropion / punctum
Madarosis / hypertrichiasis
Scarring from HZO / pigment changes
3. Conjunctiva/Sclera
Ask the patient to ‘Look up’ (while pulling the lower lid down): Symblepharon / ankyloblepharon / forniceal shortening
Ask the patient to ‘Look down’ (while pulling the upper lid up): Trabeculectomy bleb / glaucoma drainage device
Scleral buckle
Offer to evert the upper lid
4. Cornea
Always mark the visual axis.
Always draw a cross-section with corneal epithelium / stroma / endothelium, iris and lens (Figure 1.1.1). It is important to document the level, size, shape and location of any corneal lesion.
Note:
Shape: e.g. Keratoconus
Size: Measure the corneal diameter with a handheld ruler if suspicious of congenital glaucoma. Greater than 12mm in an adult is abnormal, Microcornea is defined as corneal diameter <10mm
Thinning: Estimate and document the remaining thickness as a % of normal
Scars, wounds
Corneal graft
i. Type (penetrating vs. anterior lamellar vs. endothelial)? Size? Clarity?
ii. Sutures? (interrupted, continuous, broken / loose?)
iii. Pay special attention to the graft-host junction
iv. Neovascularisation?
v. Look at the other eye for clues as to why the patient had a graft
± Tear film / marginal tear strip
In addition, look at each corneal layer:
Epithelium: Epithelial defects, punctate epithelial erosions, superficial punctate keratitis, dystrophies, microcystic oedema, Fleischer ring, limbal stem cell failure (conjunctivalisation of the cornea)
Stroma: Dystrophies, stromal oedema, vessels (superficial or deep?), prominent corneal nerves
Endothelium: Guttata, pigment dispersion, keratic precipitates (KP), Descemet’s membrane folds
The presence of one sign (e.g. a conical cornea) should prompt you to look for other associated signs of that condition (e.g. Down syndrome, vernal kerato-conjunctivitis, Fleischer ring- best seen with cobalt blue light, prominent corneal nerves, hydrops / corneal scarring and Vogt striae of keratoconus).
If an ocular surface mass is present (e.g. Ocular surface squamous neoplasia), you must exclude orbital invasion. Check for:
Lymphadenopathy
Corneal sensation
Ophthalmoplegia
Intraocular examination including gonioscopy for angle involvement
5. Anterior Chamber
Cells / flare
Hypopyon, hyphaema
Anterior chamber depth (narrow angle?). Von Herrick’s test can estimate angle depth
If an intraocular mass is present (e.g. iris melanoma), then check for:
Hyphaema
Nodular vs diffuse configuration
Ectropion uveae – seen in iris melanoma
Refractory glaucoma - raised IOP
Gonioscopy
PSEUDOSTRABISMUS.pptx
Pseudostrabismus is the clinical impression of ocular deviation
when no squint is present.
• Epicanthic folds may simulate an esotropia
• Abnormal interpupillary distance, if short may simulate an esotropia and if wide an exotropia
• Angle kappa is the angle between the visual and anatomical
(pupillary) axes.
○ Normally, the fovea is situated temporal to the
anatomical centre of the posterior pole. The eyes are
therefore slightly abducted to achieve bifoveal fixation
and a light shone onto the cornea will therefore cause a
reflex just nasal to the centre of the cornea in both eyes. This is termed a positive angle kappa.
○ A large positive angle kappa (e.g. temporally displaced
macula) may give a pseudoexotropia
○ A negative angle kappa occurs when the fovea is situated
nasal to the posterior pole (e.g. high myopia). In this
situation, the corneal reflex is situated temporally to the
centre of the cornea and it may simulate an esotropia.
Contact Lens Material.pptx
Ideal Properties
Provides sufficient oxygen
Optically transparent
Stable dimensions
Good wettability
Resists spoliation
Easily machinable
Easy to manufacture
Physical Properties
Wettability : ability of the tears to form complete film over then lens surface
Flexibility : highly flexible material will contour to the cornea
Optical quality : optically homogenous and transparent
Bicompatibility : should not induce any inflammatory or immunological responses.
Manufacturing ease : easy and cost effective
Stable parameters : dimensionally stable and easily polished.
Accommodative Facility Testing.pptx
Accommodative Facility Testing
If the patient wears glasses for close work, these should be used.
Hold Accommodative Rock Card 40 cm from the patient’s face at eye level and place the +2.00 lens in front of the patient’s eyes.
The test is initially performed binocularly.
PRROCEDURE
Ask the patient to try to get the letters clear and single as quickly as possible.
Instruct the subject to report (say “clear”) as soon as the letters are clear.
When the letters are reported to be clear, quickly flip the flipper so the minus side is before the same eye, again instructing the subject to read the letters and report when the letters appear clear or if they disappear.
Continue alternating sides of the flipper lenses for 1 minute, calculating the cycles per minute achieved (1 cycle = plus and minus).
Repeat the procedure monocularly if the patient is unable to pass binocularly. The only difference in monocular testing is that the patient only has to report when the target is clear (diplopia is no longer an issue).
Record the cycles per minute. Record if one side (plus or minus) of the flippers was more difficult, or if neither side was more difficult.
EXAMPLES
The patient can complete 18 flips in 1 minute. This equals 9 cpm.
If the patient cannot clear −2.00 at all, record as 0 cpm, fails minus.
If the patient cannot clear +2.00 at all, record as 0 cpm, fails plus.
If the patient reports diplopia, record as 0 cpm, diplopia with +2.00 or diplopia with −2.00.
IMP. POINTS
Stress the importance of trying to keep the target both clear and single
Negative Relative Accommodation and Positive Relative.pptx
EQUIPMENT NEEDED
Phoropter
Near point card with vertical line of 20/30 letters
SETUP
1. Seat the patient comfortably behind the phoropter with the patient’s distance correction in place.
2. Place the near point card at a 40-cm distance from the patient, with good illumination.
PROCEDURE
1. Instruct the patient to look at the target and keep it clear and single.
2. Instructions: “I will be changing the lenses in front of your eyes. Try to keep the line of letters clear and
single for as long as you can. Tell me as soon as the letters become blurry
3. Add plus lenses in +0.25 D increments until the patient reports the first sustained blur or diplopia.
4. Record the amount of plus added above the distance prescription as the NRA.
5. Remove the plus lenses and return to the distance prescription.
6. Add minus lenses in −0.25 D increments until the patient reports the first sustained blur or diplopia.
7. Record the amount of minus added above the distance prescription as the PRA.
8. Stop the PRA test when you reach −2.50 D above the distance prescription.
IMPORTANT POINTS
1. Stress the importance of reporting both blur and diplopia.
2. Discontinue the PRA at −2.50 D.
Vergence Facility Testing.pptx
Vergence Facility Testing
EQUIPMENT NEEDED
Gulden vergence facility prism (12 base-out/3 base-in combination)
Gulden fixation stick (20/30 target)
SETUP
1. If the patient wears glasses for close work, these should be used.
2. Hold Gulden fixation stick tongue depressor 40 cm from patient’s face at eye level.
PROCEDURE
1. Say the following: “I want you to look at the letter on this stick. When I place this measuring device in
front of your eye, you will see double. Try to get the target to be clear and one as soon as possible. Say
‘now’ as soon as it is clear and one.”
2. Begin with either base-out or base-in and count how many cpm the patient can complete in 60 seconds
(one cycle equals successful completion of both base-out and base-in).
3. Record the number of cpm.
4. If the patient cannot do either base-in or base-out, record as 0 cpm, fails base-out or base-in.
5. If the patient cannot do both, record as 0 cpm, cannot do base-in or base-out.
EXAMPLES
1. The patient can complete 18 flips in 1 minute. This equals 9 cpm.
2. If the patient cannot regain single and clear vision at all, record as 0 cpm, fails both base-in and base-out.
3. If the patient cannot regain single and clear vision with base-in, record as 0 cpm, fails base-in.
4. If the patient cannot regain single and clear vision with base-out, record as 0 cpm, fails base-out.
IMPORTANT POINTS
1. Control accommodation by stressing the importance of keeping the target clear.
2. Stress the importance of trying to regain clear and single vision as quickly as possible
NPC.pptx
EQUIPMENT NEEDED
Penlight
Gulden fixation stick
Red/green glasses
SETUP
1. If the patient wears glasses for close work, these should be used.
2. Hold Gulden fixation stick tongue depressor 40 cm from patient’s face at eye level.
3. Ask the patient to look at the isolated 20/50 target on the Gulden fixation stick.
PROCEDURE
1. Slowly move the fixation stick toward the patient at eye level and between the two eyes.
2. Ask the patient to keep the target one for as long as possible.
3. Ask the patient to tell you when he or she sees two targets.
4. Once diplopia occurs, move the fixation stick in another inch or two and then begin to move it away from the patient
5. Ask the patient to try and see “one” again.
6. Also watch the eyes carefully and observe whether the eyes stop working together as a team (one eye will usually drift out).
7. Record the distance at which the patient reports double vision and when the patient reports recovery of single vision.
8. Repeat the test using a penlight and red/green glasses if you suspect that dissociation may reveal a more receded NPC.
IMPORTANT POINTS
1. Repeat the test several times if results are not definitive.
2. Watch the patient’s eyes and try to objectively determine when the break and recovery occur
ASOP-06-0634.pdf
Background: Strabismic amblyopia is characterized by an imbalance of the sensorial and motor system. Differences between both
eyes due to squinting during 1st months of life can originate an entire fovea fixation and ARC, which is a binocular condition generated
by the absence of a correct bi-foveal fixation [2]. Accommodative esotropia usually presents between 2 and 4 years of age with an
increase in accommodative needs and is directly linked to the amount of hypermetropia [9]. Although patching remains the gold
standard therapy of amblyopia, several new treatment options have emerged over the years. These include refractive adaptation,
atropine penalization, and several binocular activities with varying success rates [10].
Case Report: 6-year-old male presented with complaints of inward deviation, and blurring of vision for distance and near. A proper
squint evaluation was performed to determine the presence of the type of squint. Accommodative esotropia with amblyopia in one
eye was reported. Synoptophorehaidinger brushes were recommended for foveal stimulation for the amblyopic eye followed by
patching. The patient reported good compliance and significant vision improvement in the amblyopic eye and no longer blur and
deviation with glasses were observed.
Conclusion: Accommodative esotropia with amblyopia showed substantial improvement with the help of Haidinger brushes in the
amblyopic eye. A combination of patching and Haidinger brushes is an efficacious approach for achieving an improvement in visual
acuity and binocular function in strabismic amblyopia.
Keywords: Accommodative Esotropia; Strabismic Amblyopia; Haidinger Brushes; Synoptophore
diplopia-201224103449.pptx
This document provides guidance on evaluating patients presenting with diplopia. It outlines key questions to ask the patient regarding the orientation and characteristics of the double vision. Examining the eye movements, lids, and pupils can help localize the cause. Systemic neurological symptoms or asymmetric pupils indicate potentially serious conditions like aneurysm that require immediate imaging. Isolated cranial nerve palsies are often due to ischemia. Multiple cranial nerve involvement raises concern for life-threatening conditions like tumor or stroke within the cavernous sinus. Refractive errors and decompensating phoria are common causes of intermittent diplopia.
SYNAPTOPHORE.pptx
SYNAPTOPHORE
Also known as major amblyoscope
It is haploscopic device based on mechanical dissociation of the two eyes , by the means of two optical tubes
Strength of the lenses with eyepiece +6.50D
OPTICS OF SYNAPTOPHORE
Consist of :
Light source
Slide of focal length of lens
Plane mirror
+6.50D eyepiece
SLIDES
Range of slides
Size of picture on the slides subtends , visual angles of different degrees at nodal point .
Simultaneous macular perception (SMPp slides
Fusion slides
Stereopsis slides
After image slides
Haidinger brushes
NSBD.pptx
This document summarizes non-strabismic binocular dysfunction (NSBD), which refers to visual abnormalities that remain undetected in individuals with normal eye health and no strabismus. It describes the components of binocular single vision and covers evaluation procedures like cover testing, phoria measurement, near point of convergence, and tests of fusion, vergence, and stereopsis. Common forms of NSBD like convergence insufficiency, divergence excess, and various types of phoria are explained. Treatment options focus on refractive correction, addition of prisms, and vision therapy.
CASE PRESENTATION ON OPTIC NEURITIS
Swelling of the eye’s optic nerve
Optic nerve carries light signals from the back of the eye to the brain , so that person can see.
If optic nerve is swollen , damaged or infected , we can’t see clearly .
This condition may caused by the body’s immune system attacking optic nerve tissue
Seems more likely to happen in people who have viral problems like mumps , measles , and the multiple sclerosis etc.
Symptoms :
It can be unilateral and bilateral
Symptoms : include : -
Blurring of vision
Colors appears dull and faded
Pain in the back of the eye socket
Pain when moving eyes
Stereograms vergence therapy
Stereogram exercise helps to improve the symptoms of convergence insufficiency , divergence excess etc
Ideally only one central complete image should be seen . three images with two partial and central complete image is also acceptable .
The image appear slightly out of focus as the concentration is on the pen tip
This exercise should be done with patients glasses on .
Binocular vision
This document discusses binocular vision and its evaluation and treatment. It defines binocular vision as the coordination of the two eyes to align their foveas on an object, allowing for fusion. It describes various binocular vision disorders like esotropia, exotropia, convergence and divergence insufficiencies, and accommodative disorders. It outlines tests to evaluate the magnitude and type of deviation, accommodative amplitude and response, and binocular vision status. Finally, it discusses treatment options for binocular vision disorders like optical correction, plus adds, prism, vision therapy, and surgery.
Clinical case presentation
ANTERIOR UVEITIS
Inflammation of iris and ciliary body.
Also called iritis ,iridocyclitis,cyclitis.
Iritis:- inflammation predominantly affects iris
Iridoclyclitis:- involved iris and pars plicata part of C.B. equally involved.
Cyclitis :-in which pars plicata part of C.B. is predominantly affected.
It can be : Acute and Chronic
Acute: sudden symptomatic onset and last for about six weeks to 3 months.
Chronic : asymptomatic onset and it persist longer than 3 months to even years and it usually diagnosed when it causes defective vision.
Soft contact lens (1) (1)
Optical- Anisometropia, unilateral aphakia, myopia, low astigmatism
Therapeutic- corneal scar, iris abnormalities, post keratoplasty, microbial keratitis, amblyopia ( opaque lens) glaucoma etc.
Cosmetic- corneal scar, phthsis bulbi
Occupational- sportsman, pilots, actors
Binocular interaction in amblyopia and its clinical feasibility
BINOCULAR INTERACTION ITS ASSOCIATION WITH AMBLYOPIA
Apart from binocular summation, the two eyes can influence each other in at least three ways.
Pupillary diameter. Light falling in one eye affects the diameter of the pupils in both eyes. One can easily see this by looking at a friend's eye while he or she closes the other: when the other eye is open, the pupil of the first eye is small; when the other eye is closed, the pupil of the first eye is large.
Accommodation and vergence. Accommodation is the state of focus of the eye. If one eye is open and the other closed, and one focuses on something close, the accommodation of the closed eye will become the same as that of the open eye. Moreover, the closed eye will tend to converge to point at the object. Accommodation and convergence are linked by a reflex, so that one evokes the other.
Interocular transfer. The state of adaptation of one eye can have a small effect on the state of light adaptation of the other. Aftereffects induced through one eye can be measured through the other.
Singleness of vision
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3. Chapter 13, Human Physiology by Lauralee Sherwood, 9th edition
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Soft Contact Lens Material.pptx
- 1. Soft Contact Lens Material By Babli Sharma B.Optom, M.Optom
- 2. Hydroxyethyl-methacrylate PHEMA O Wichterle and D Lim A polar OH group to which water lipole binds 38% water content Are soft and pliable Large lens diameters New generation-soft material-improved PHEMA combination of other polymers 2-3
- 3. Physical Properties Water content Ranges from 38%-80% >40% are low water content Dk range 5-8 Low oxygen permeability Low water content lenses are stable, Easier to handle More wettable 40-55% are mid water content Dk range 7- 19 >55% are high water content Dk range 18- 28 Higher the water content greater the oxygen permeability Less stable Fragile More deposit prone Less dimension stability Thicker due to low refractive index
- 4. Ionicity Ionicity Ionic Net Negative charge More prone to deposits Better wettability Nonionic No net surface charge Less deposit prone Less wettable
- 5. FDA Classification Groups In 1986 US food and drug administration classified hydrogel contact lenses into 4 groups • Non ionic Low water content 38-50% Group -1 • Non-ionic High water content 51-80% Group-2 • Ionic Low water content 38-50% Group-3 • Ionic High water content 51-80% Group-4
- 6. Soft materials and Dk-depends on Water content if higher increases Dk Material chemistry If pH is acidic it reduces water content Hyper tonicity reduces water content
- 7. Thank you