CASE PRESENTATION

MIKAH TCHALE

ACKNOWLEDGEMENTS

MR SYMON CHIKUMBA, optometristMR JALLIFF CHITSEKO, optometrist

PATIENT’S PARTICULARS

NAME: RTAGE: 21SEX: FLOCATION: AREA 1BOCCUPATION: SECONDARY SCHOOL STUDENT

CASE HISTORY

CHIEF COMPLAINTTearing and eyestrain with prolonged near work

OCULAR Hx: has an ocular allergy and currently on treatment ie sodium cromoglycate

MEDICAL Hx: N/SFAMILY Hx: N/S

OCULAR EXAMINATION

VISUAL ACUITYi. DISTANCE

OD: 6/6OS: 6/6

ii. NEAR OD:N5 OS:N5

ANTERIOR SEGMENTOD OS

NAD LIDS NAD

PAPIILLAE CONJ PAPILLAE

CLEAR CORNEA CLEAR

RRLA PUPILS RRLA

DEEP & QUIET AC DEEP & QUIET

CLEAR LENS CLEAR

DIRECT OPTHALMOSCOPY

OD OS

0.3 CD RATIO 0.3

HEALTHY OPTIC DISC HEALTHY

NAD MACULA NAD

2:3 AV RATIO 2:3

WNL PERIPHERY WNL

NON CYCLOPLEGIC REFRACTIONOD: +0.25D….6/6OS: +0.25D….6/6

The patient was sent home and told to come the next day for binocular vision assessment and cycloplegic refraction

OCULAR MOTILITY: SAFE

COVER TESTi. DISTANCE: 4∆ XOPii. NEAR: 6∆ XOP

NPC: 5/8 cm

IPD: 62mm

CONFRONTATIONAL VISUAL FIELDS (PERIPHERAL FINGER COUNTING AND FACIAL AMSLER)FULL (ou)

AMPLITUDE OF ACCOMMODATIONOD: 4.4DOS:4.5DOU:5.0D

NRA: +0.50PRA: -1.00

DYNAMIC RETINOSCOPYOD: +0.75OS: +0.75

ACCOMMODATIVE FACILITYOD:2cpmOS: 2cpmOU: 1cpm

CYCLOPLEGIC REFRACTIONOD:+0.25…6/6OS: PLANO…6/6

CALCULATED AC/A RATIOIPD (cm) + NFD (m) [Hn-Hf]5.4:1

AC/A ratio is a key element in the appropriate managementHigh AC/A ratio→ plus lensesLow/normal AC/A ratio→ prisms/vision therapy

EXPECTED FINDINGS

1) NPC Break point: 5cm±2.5 Recovery: 7cm ±3.0

2) Accommodative facility Children (monocular| binocular)

6yrs old: 5.5cpm±2.5 | 3cpm±2.5 7yrs old: 6.5cpm ±2.0 | 3.5cpm±2.5 8-12yrs old: 7cpm±2.5 | 5cpm±2.5

Adults13-30yrs old: 11cpm±5 | 10cpm±5.030-40 yrs: not quantified

4) Relative accommodation NRA: +2.00D±0.50 PRA: -2.73D±1.00

5) MEM: +0.50±0.256) AC/A Ratio: 4:1±2

DIFFERENTIALS

Basic exophoriaAccommodation insufficiencyFusional Vergence dysfunction

FINAL DIAGNOSIS

FUSIONAL VERGENCE DYSFUNCTION

TREATMENT

Jump exercises 3x/day for 1 monthReview after 1 month

LITERATURE REVIEW

FUSIONAL VERGENCE DYSFUNCTIONSYMPTOMS

Eyestrain and headaches after relatively short periods of near work

Inability to concentrateExcessive tearingBlurred visionLoss of comprehension over time

ETIOLOGY AND PREVALENCEEtiology is not knownPrevalence is not clearly defined in literatureSome researchers reported a prevalence of 0.6% in

children of 6-18 yrs; 1.6% in university students

SIGNSNormal AC/A ratioPhoria within expected values at distance and nearBinocular instabilityDo not have a high degree of RELow NRA and PRA (these can be considered an indirect

measure of fusional vergence)Low accommodative facility

TREATMENTVision therapyPlus lenses (increase integration of accommodation

and vergences that then facilitates stable binocular function)

VISION THERAPY FOR FVDi. 1st PHASE: Normalise accommodative and

vergence amplitudesii. 2nd PHASE: Increase the speed of response to

accommodative and vergence stimuliiii. 3rd PHASE: Utilise step &/or jump vergence stimuliiv. 4th PHASE: Integrate vergence and

accommodation to automate both accommodative and vergence response