viav Flashcards
Assessment of poor near vision:
Vergence:
Heterophoria: should be <2PD, more exo at near
- Cover test w/prism
NPC/A: <10, <12 (break/recovery). <10 (accomodation, decreases with age)
- Should report diplopia, otherwise suppression
Fusional reserve:
- NFV (base-in): Near (10,15,10)
- PFV (base out): Near (15,25,20)
Fixation disparity: Misalignment within panums > asthenopia
- Eso/exo: Mallet unit
Stereopsis: 40 seconds of arc or better
- Titmus Fly, or Randot
Accommodative:
Stimulus to accom: Power needed to view object
Lag/Lead of accom: Normally a Lag of +0.5D
- Difference of accommodative power to STA
- Cross-cylinder: Horizontal lines clear > lag (needs plus lens) and vise versa
- MEM: Ret with near target
Range of accom: Distance from far to near point
Accommodative facility: 12 (mono), and 10 (Bino)
- +-2D flippers, cycle once target is cleared
- Low monocular facility is accommodative problem
- Vergence problem if mono is fine
Amplitude of accom: 18.5-(0.3*age)
- Minus lenses until near target blurs
- 1/amp is sustainable
Relative accom: NRA +2D, PRA -2.5D
- NRA: +ve lens until near target blur
- PRA: -ve lens until blur
- ^amplitude of accom > diplopia, and vise versa
- Tentative ADD is NRA - (NRA+PRA)/2
Gradient AC/A: 4:1
- Howell card
- Amount of convergence per D of accom.
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
Penetrating injury procedure:
Assessment:
- Optic section of cornea
- Iris and lens
Removal:
- dilate metal-on-metal
- Use needle 25 gauge
Cleaning: rust rings
- Alger brush
Therapetics:
- NEVER patch
- Chlorsig 0.5 QID unless vegetive
- topical NSAID for pain
- BCL
Prelims:
**VA: **
- Pinhole, Unaided/aided, Near/far, Mono/Binocular
PD:
- Near/far
Pupils:
- PERRL
- RAPD
Motility:
- Pain/Diplopia
**Cover test: **oculomotor balance
- Distance/Near
- Alternating/Unilateral
NPC
Stereopsis: Randot
Tests after prelims
Confrontation
Retinoscopy:
- Cyclo
Subjective Refraction:
- With binocular balance (humphriss)
Anterior examination:
- Lids/lashes
- MGD
- Discharge
- cornea/conj.
- VH temporal and nasal
- evidence of PXF/PDS
- AC (deep/empty)
- NaFl staining
- TBUT
**IOP: **goldmann
Posterior examination: tropicamide
Fundoscopy:
- Disc
- CDR
- ISNT
- PPA
- Rim healthy/distinct margins
- Macula reflex
- AV
- Peripehral retina tears
Biometry:
Ultrasound:
- A-scan: Axial length (IOL calculation)
- B-scan: Structure abnormality
- Ultrasound pachymetry: common CCT
OCT:
- Anterior: CCT, AC, Cornea, Iris
Coherence reflectometry:
- Topography, and thickness
Tests for Near work:
**BC/VA: **near/far
**Prism Cover test: **vergence phoria
- Von Grafe after ct for accuracy
**NPC: **Vergence
NRA/PRA
NPC/NPA
Fusional reserve: Vergence
**Cross-cyl: **Lag/lead
Dynamic ret (MEM): Lag/lead
**Stereopsis: **steriofly/randot
Fixation disparity: Mallet unit
**Anterior assessment: **
- Media opacities
- VH: Glaucoma
- Lens: Cataract
Posterior assessment:
- CDR: Glaucoma
- Fovea reflex: AMD
- Vasculature: DR
IOP: glaucoma
- GAT, after corneal health check (HSV/damage)
Ishihara: DM
- 3 or more errors indicate vision defect
- Followed by Farnsworth D-15 (more than 1 crossing)
Red eyes:
VA (unless chemical)
Hx
- DEQ-5/OSDI
MG assessment
- Red-free
- Meibometry
- Expression
Tear film:
- TBUT
- Osmolarity
Lids:
- Double-/Eversion
- Papillae/follicles
- Puncta/Lacramal lavage
- Lash/trichiasis
Conjuntiva:
- Schirmers
- Lid wiper epitheliop
Cornea:
- Seidels sign
- NaFl, Rose Bengal
AC:
- Gonio/VH
Glaucoma:
IOP
Pachymetry
Gonio
VF
DFE
- Stereoscopic disc evaluation
Imaging
Disc assessment:
Size of disc (distance from macula)
NRR clarity
CDR
ONH vessels/haem
Laminar dot
PPA
OCT
- RNFL (also seen on red free)> OD glaucomatous damage
- GCL > Early glaucoma signs at macula
