resd Flashcards
Evaluation of Optic Disc:
- CDR: < 0.5, asymmetry of 0.2
- NRR: ISNT, notching
- ONH: Distinct, within 2.5DD (2mm)
- PPA: no beta atrophy
- RNFL: vertical thinning
- BVs: Nasalation, bayonetting
- Color: Pink
Risk signs
- Drance haem
- Laminar dot
- Cupping
Assessment of tear film:
- Hx: DEQ-5/OSDI
More than 5/ >12>22>32>100 - TFBUT: NaFl-Wratten/Placido-disc
Seconds > 10 > 15 - Tear production: Schirmers/Phenol-red
Wo/ Anesthetic: 15>10> Less than 10mm in 5min
Anesthetic: 10>5> Less than 5mm - Tear outflow: Jones dye
- Tear quality: Osmolarity
Greater than 308mOsm/L - MGD: Red-free/Meibometry/Expression
Clear fluid, uniform glands - Ocular surface: NaFl/meniscus
SPEE, lid wiper epitheliopathy, TMH > 0.2mm - MMP testing
Positive for inflammation
Assessment of the conjunctiva:
- Hyperemia: diffuse/Circumlimbal
- Discharge: watery/mucoid/purulent
- Chemosis
- Lesions: OSSN/Pterygium
- Papillae/Follicles: Tarantas/GP
Assessment of the cornea:
- Corneal sensation:
Neuropathy - Staining:
SPEE, Ulcers - Topography: Placido disc
Irregular astigmatism - Pachymetry: CCT
540-560um - Anterior-OCT
Depth of lesions - Corneal nerve size
DM, keratoconus, acan.
PDX and PDS signs:
PDX:
- Exfoliative material on pupil margin
- Iris tranillumination defect at pupil ruff
- Three ring sign
- Pigment in TM
PDS:
- Mid-peripheral iris transillumination defect
- Heavy TM pigment
- Krukenberg spindle
Signs of the cornea:
- KP’s: Uveitis
- Mutton KP’s: Granulomatous uveitis
- SPEE: DED, CL’s
- Fleischer: Metal ring
- Krukenberg spindle: PDS
Ulcers/Infiltrates
- Dendritic: HSV
- Disciform central: Bacterial
- Ring: Acan.
- Pannus: NV from lumbus
Keratopathy
- Bullous: endothelial decomposition
- Edema: Glaucoma
- Hydrops
Assessment of the anterior chamber:
- Gonio: TM and structures
CBB, TM<+1
Indentation > PAS
Plateau iris (double hump) - AS-OCT: Depth, Iris
Shallow > PACG
Deep > Marfans - Ultrasound biometry: Ciliary body
- Van-herick: 1:1
Signs of the anterior chamber:
- Cells/Flare
SUN grading - Hyphema
Trauma/NV - Hypopyon
Infectious keratits, uveitis, endophthalmitis - Pigmented cells
PDS/PDX - Posterior synechiae
Uveitis - PAS
NV glaucoma, Chronic ACG - Angle recession (CB tear)
Trauma
OCT assessment:
RNFL Optic disc cube:
- Average thickness
<80<70<50< Mild/Moderate/Severe - Quadrant Thickness
Sup/Inf: <100
Nasal/Temp: <50 - ONH
Disc Area: <>1.5-2.5mm
Rim area: < 1-2mm
Cup volume: >0.1-0.3mm
Vertical CD: > 0.65 - Deviation map
Asymmetry; focal/diffuse
Arcuate, correlated to VF defect
GCL macular cube:
- GCL+IPL thickness average
70-90 - Sectoral GCL:
70-100 - Macula thickness: Edema/Atrophy
250-310 - Deviation map
Asymmetry
Early superior/inferior loss
Corneal topography assessment:
- Axial map: Symmetrical Bow-Tie <47 steepest K
KC > Inferior steepening, K>47 - Tangential: Smooth curvature
KC > Localized steepening, asymmetry - Elevation map: Smooth
KC > Significant inf elevation - Indices:
Inf./Sup. (I-S): >1.50D
Surface asymmetry (SAI): >1.0
Surface irregularity (SRI): >0.80
Accomodation assessment:
- Amplitude: Push-up
18-(0.3 * age) - NPA:
10>25>100cm for 20>40>60 - NRA/PRA: +/- until near blur
+2.00-2.50 / -2.00-3.00 - Accom. facility: +/-2.00 flipper clearance
12cpm mono
8cpm bino - Accom. lag/lead: Fused cross/cyl and MEM
Lag of +0.25
CVD test pass/fail:
- Ishihara/HRR
3 Probable > 5 Definite
2 probable > 2 definite - Farnsworth D15
2 Crossings - Medmont: women carriers of protanopia
Minus (protan) plus (Deutan) - Anomaloscope: Red-Green
Vergence assessment:
- NPC: Break/recovery
5-10cm / <5 from break - Phoria: Howells/Von graefe
Near: 6 Exo to 3 Eso
Dist: <2 exo - N/P Fusional vergence: Risley/Prism bar
PFV: 15/25/20 (+-10)
NFV: 10/15/10 (+-3)
Vertical: <3 - AC/A: Gradient (Howell/Flipper), Calculated (Cover/Prism)
4:1 - Fixation disparity: Mallet unit
- Vergence facility: 3BI/12BO
10-15cpm
Clinical response to older Px for poor reading:
Age based table:
- From 40/45/50/55/60 > +1/1.25/1.75/2.25/2.5
- Amp norm is 5/3.25/2/0.75/0
Plus build up W/age norm in trial frame
- Provides Amp
Convert Amp to proportion of amplitude
- Reading add should allow half accom. at habitual
Using found Add, blur check with fused-cross
- -0.50 at 90, w/+2.50 fog
- reduce power until equalised
Convert N5 and 40cm to snellen:
If N8 = 1M, N1 = 0.125M
N5 = 0.625M
40cm/0.625M = 0.4/0.625 = 6/9.375
Suppression assessment
- Worth 4 lights:
5 (manifest), 3 (RE sup), 2 (LE sup) - Sterio: Randot/Steriofly
20-40 arcsecs - 4BO: Observed vergence
CVD causes:
Protan/Deutanopia: X-linked recessive
- Red (L-cones), or green (M-cones) completly missing
- P/D-anomaly > mild form where photopigments are altered
Tritanopia: Autosomal recessive
- Blue (S-cones)
Acquired:
- Cataract (contrast loss)
- Glaucoma/MS (blue yellow loss)
- AMD (contrast loss)
- DR (blue/yellow > red/green)
- RP
Dissociated phoria tests:
Cover-uncover:
- Tropia > uncovered eye moves
- Phoria > covered eye moves when uncovering
Alternating cover:
- Determines degree of phoria
Phi phenomenon: subjective
Prism cover test:
- amount of prism required to remove phoria or tropia
Maddox rod: Vertical streak (horizontal phoria) or horizontal streak for vertical
- Used in case of suppression
- Eso if Px sees line left of light source
Vone graefe: 6BU and 15BI
- Decrease horizontal OR vertical to determine horizontal or vertical phoria
Howel phoria card
Soft contact lens selection and example order:
- Material > Spherical/aspheric
- Hydrogel: ^comfort for short term wear
- Silicone hydrogen: ^O2 permeability for long term wear - SCL 2mm larger than HVID (keratometry/slit)
- Base curve 0.6mm flatter than mean K (keratometry)
- Flat K + 0.6mm - BVP from refraction
- 4D > +0.25
- 6D > +0.50…
- If > 1 DC, use toric
Example order: Acuvue Oasys 8.4/14.0/-2.00D (BC/TD/BVP)
Cause of deviations:
Comitant:
- Congenital strabismus (Tropia)
- Accomodative esotropia (hyperopia)
- Intermittent exotropia
- Genetic/anatomical factors
Incomitant:
- CN 3/4/6 palsy
- TED
- MG
- Chronic progressive external ophthalmoplegia
Incomitant deviation clinic:
- Cover test: measure deviation of each eye while the other if fixing > Greater deviation in non paretic eye (herring’s law of equal innervation)
- Hess screen: R/G dissociation > R fixation and G pointer > Px marks where the fixation light is
1. Smaller chart is parietic eye
2. Degree of disparity gives angle of deviation - Parks 3 step: determines parietic muscle from Rectus or Oblique muscles
1. Which is hyper (Hyper eye’s IR/SO, or Hypo eye’s IO/SR)
2. Worse on R/L gaze (Gaze’s IR/SR, or opposite’s IO/SO)
3. Worse on R/L tilt (Tilt’s SR/SO, or opposite’s IO/IR)
Clinical management of phoria:
Sheards criterion > Opposing fusional reserve must be at least twice the phoria
- If 6 exo
- PFV > 12 BO, phoria is compensated
- PFV = 8 BO, a 2 BI lens in required (is now a 4PD exo)
Percival’s criterion > PFV+NFV = 10
- PFV ~20 BO
- NFV ~ -10 BI
DED management:
DEWS step 1:
- Educate: DED lifelong
- Environment (masks, computer time)
- Diet change
- Cease offending medications
- Ocular lubricants
- Lid hygiene, warm compress
- 45’ towel, reheated every 2 mins for 10 mins
Step 2:
- Non-preservative tears
- Tea-tree oil for demodex
- MG expression
- short term cortico.
- FML QID shown to reduce symptoms and increase goblet density
- Immunomodulatory drugs
- Ciclosporin to prevent T-cell activation
Step 3:
- Autologous serum drops
- BCL
- Soft > comfort
- RGP scleral > tear repository
Step 4:
- Long term cortico.
- Amniotic membrane graft
- Surgical occlusion
Poor near vision DDX:
Accom insuf: Blur/Asthenopia at near
- Low amplitude
- Cover test: Esophoria at near
- Poor facility clearance on minus lenses
Accom excess: Dist. blur after near (Latent hyperope)
- Variable VA/ret
- High amplitude
- Poor facility clearance on plus lenses
- Esophoria at near
Accom infacility: Blur/asthenopia at near, poor target switching
- Poor mono and bino facility on both lenses
Convergence insuf: Diplopia at near
- Poor NPC
- Exo at near
- Poor fusional reserve and AC/A
Convergence excess: Diplopia at near
- Eso at near
- High AC/A
