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.

1. NON STRABISMIC BINOCULAR
DYSFUNCTION
PRESENTER - BABLI SHARMA (B.OPTOM , M.OPTOM)
DHIR HOSPITAL & POST GRADUATE INSTITUTE OF OPHTHALMOLOGY

2. o INTRODUCTION
• WHEN A NORMAL INDIVIDUAL FIXES HIS VISUAL ATTENTION ON AN
OBJECT OF REGARD ,THE IMAGE IS FORMED ON THE FOVEA OF THE
BOTH EYES SEPARATELY ,BUT THE INDIVIDUAL PERCEIVES A SINGLE
IMAGE .
• BINOCULAR SINGLE VISION CONSIST OF 3 GRADES :
SIMULTANEOUS MACULAR PERCEPTION
FUSION
STEREOPSIS
REFERENCE:-

3. • SIMULTANEOUS MACULAR PERCEPTION :
POWER TO SEE TWO DISSIMILAR OBJECTS
SIMULATANEOUSLY
• FUSION :
POWER TO SUPERIMPOSE TWO INCOMPLETE BUT
SIMILAR IMAGES TO FORM ONE COMPLETE IMAGE
• STEREOPSIS :
ABILITY TO PERCEIVE THE 3RD DIMENSION (DEPTH
PERCEPTION )

4. o NON-STRABISMIC BINOCULAR DYSFUNCTION :
• COMMON FORMS OF VISUAL ABNORMALITIES
• USUALLY REMAIN UNDECETED
• SYMPTOMATIC EMMETROPE /NEAR EMMETROPE
• NO DEMONSTRABLE STRABISMUS
• NORMAL EYE HEALTH
• IMPACTS LEARNING ABILITY OF A CHILD
• PATIENT USUALLY C/O ABOUT : EYESTRAIN ,DIPLOPIA ,HEADACHES ,SLEEPINESS ,BLUR,
WATERING ETC.

5. o ROUTINE OPTOMETRY PROTOCOL FOR EYE EXAMINATION :
• COMPLAINT AND HISTORY
• VA (AIDED,UNAIDED,PIN HOLE)
• RETINOSCOPY OR AR
• SUBJECTIVE BCVA
• GROSS EVALUATION OF EYE HEALTH(ANTERIOR AND POSTERIOR )
• BASIC MOTILITY
• CT
• NPC
• QUANTIFICATION FOR HETEROPHORIA AT D & N
• AC /A RATIO
• ACCOMMODATION FUNCTIONS
• FUSIONAL VERGENCE RANGES AT D& N
• SENSORY FUSION AT D & N
• STEREOPSIS

6. o COVER TEST :
• UNILATERAL CT
USED TO DETECT STRABISMUS
• COVER– UNCOVER TEST
USED TO DETECT PHORIA
• ALTERNATE CT
USED TO ASSESS AMOUNT OF PHORIA AND STRABISMUS
o PHORIA MEASUREMENT
• MADDOX ROD METHOD
• MODIFIED THORINGTON TEST
• NORMAL VALUE :
DISTANCE : 1 -2 EXO
NEAR : 4-6 EXO

7. o NPC :
• ASSESS CONVERGENCE AMPLITUDES
• BOTH BREAK AND RECOVERY WILL BE NOTED
• TARGET USED SHOULD BE ACCOMMODATIVE
• DONE BY RAF RULER
• DONE BY PENLIGHT WITH RED LENS
NORMAL : BREAK 5-6 CM
RECOVER 7-10 CM
o AC/A RATIO :
• DETERMINE THE CHANGE ON ACCOMMODATIVE VERGENCE THAT OCCURS WHEN THE PT
RELAXES OR STIMULATES ACCOMMODATION BY THE GIVEN AMMOUNT
• CALCULATED BY GRADIENT METHOD
NORMAL : 4 : 1

8. o ACCOMMODATIVE FUNCTIONS :
o NPA
• PUSH UP AND PULL AWAY METHOD :
• NEAR POINT CARD AND FIXATION TARGET
• RAF RULLER
• CAN BE DONE MONOCULARLY AND BINOCULARLY
• NORMAL : 6-10 CM
o ACCOMMODATIVE FACILITY
• DONE WITH FLIPPERS
• MONOCULAR AND BINOCULARLY
• NEAR POINT CARD
• NORMAL : BAF : 8-10 CPM
MAF: 11-12 CPM

9. o MEM :
• TO OBJECTIVELY DETERMINE THE LEAD AND LAG OF
ACCOMMODATION
• DONE WITH MEM CARDS
• NORMAL : +0.50 - +0.75D
o NRA – PRA
• BINOCULAR PROCEDURE
• SHOULD BE DONE WITH PT HABITUAL CORRECTION
READING OR DISTANCE
• PT IS INSTRUCTED TO REPORT FIRST SUSTAINED BLUR
NORMAL :
PRA : -2.25D
NRA : +2.50

10. o FUSIONAL VERGENCE RANGES :
• ASSESS THE AMPLITUDE OF FUSIONAL VERGENCE
• RESPONSE FOR BOTH POSTIVE AND NEGATIVE
FUSIONAL VERGENCE
• BLUR/ BREAK / RECOVERY
• NORMAL
PFV NEAR : 17/21/11 DISTANCE : 9/19/10
NFV NEAR : 13/21/13 DISTANCE : X/7/4
o VERGENCE FACILTY :
• ASSESS THE DYNAMICS OF FUSIONAL VERGENCE
SYSTEM AND THE ABILITY TO RESPOND OVER TIME
12 BO /3BI
NORMAL : 8-10CPM

11. o FUSION AT D&N
o WORTH 4 DOT TEST
• TO TEST THE FUSION STATUS AND SUPPRESSION
RECORDING :
• DISTANCE : FUSION/SUPPRESSION/DIPLOPIA
• INTERMEDIATE: FUSION/SUPPRESSION/DIPLOPIA
• NEAR : FUSION/SUPPRESSION/DIPLOPIA

12. o STEREO TESTING
• TITMUS FLY TEST / RANDOM DOT
STEREOPSIS
• EVALUATE THE DEGREE AND PRESENCE OF
STEREOPSIS
• NORMAL 40 SEC OF ARC

13. SYMPTOMS
ASSCOCIATED
WITH USE OF
EYES
VA IS
NORMAL
REFRACTION
IS NORMAL
BINOCUL
AR VISION
PROBLEM
?
BV PROBLEM ? D&N PHORIA
EXOPHORIA IS
PRESENT
INVESTIGAT
E AND
ANALYSE
PFV DATA

14. EVALUATE AC/A
RATIO AND
COMPARE D&N
PHORIA
PHORIA D>N
DIVERGENCE
EXCESS
PHORIA D <N
CI
PHORIA D = N
BASIC
EXOPHORIA

15. BV PROBLEM D &N PHORIA
ESOPHORIA IS
PRESENT
INVESTIGATE
NFV DATA
EVALUATE AC /A RATIO
AND COMPARE D&N
PHORIA
PHORIA D>N
DIVERGENCE
INSUFFICIENCY
PHORIA D <N
CONVERGENCE
EXCESS
PHORIA D = N
BASIC
ESOPHORIA

16. BV PROBLEM
?
D &N
PHORIA
NO
SIGNIFICANT
PHORIA D&N
CONSIDER
ACCOMMODATI
VE PROBLEM
INVESTIGATE AND
ANALYZE
ACCOMMODATIVE
GROUP DATA
ALL MINUS
LENS TEST ARE
LOW
AI
ALL PLUS LENS
TEST ARE LOW
AE
PLUS AND
MINUS TEST
ARE LOW
ACCOMMODA
TIVE
INFACILITY

17. NO PHORIA AND
ACCOMMOADTIV
E FINDINGS
NORMAL
CONSIDER FVD
CONSIDER LATENT
HYPEROPIA,VERTICLE
CYCLOPHORIA ANISEIKONIA
NO PHORIA AND
ACCOMMOADTIVE
FINDINGS NORMAL
CONSIDER FVD
ANALYZE DATA
APPROPRIATE FOR
FVD
LOW PHORIA,LOW
BI,LOW BO, LOW
NRA AND PRA,
LOW BAF

18. TYPES OF NSBD PRIMARY RX OPTIONS
CONVERGENCE INSUFFICIENCY LOW PLUS AT NEAR, BI PRISM, VT
CONVERGENCE EXCESS ADDED PLUS AT NEAR ,VT
DIVERGENCE INSUFFICIENCY RELIEVING PRISMS WITH REFRACTIVE
RX , VT
DIVERGENCE EXCESS REFRACTIVE RX , VT
BASIC EXOPHORIA RELIEVING PRISM,VT
BASIC ESOPHORIA ADDED PLUS , VT
AI ADDED PLUS ON REFRACTIVE RX, VT
AE ADDED PLUS, REFRACTIVE RX, VT
ACCOMMODATIVE INFACILITY REFRACTIVE RX , ADDED PLUS, VT
FVD REFRACTIVE MODIFICATION , VT
SUMMARY OF TX OPTIONS FOR NSBD

19. REFERENCE
• AK KHURANA ,COMPREHENSIVE OPTHALMOLOGY
• CLINICAL MANAGEMENT OF BINOCULAR VISION BY MITCHELL SCHEIMAN
• COVD – WWW.COVD.ORG

20. THANK YOU