MYOPIA. MYOPIA : PROGRAM Myopia: program I Generalities –Definition...

download MYOPIA. MYOPIA : PROGRAM Myopia: program I Generalities –Definition –Etiology –Epidemiology Classification: –According to magnitude –Clinical

of 58

  • date post

    13-Jan-2016
  • Category

    Documents

  • view

    234
  • download

    3

Embed Size (px)

Transcript of MYOPIA. MYOPIA : PROGRAM Myopia: program I Generalities –Definition...

  • MYOPIA

  • MYOPIA : PROGRAM

  • Myopia: program IGeneralitiesDefinitionEtiologyEpidemiologyClassification:According to magnitudeClinical

  • Myopia: program IIMyopia simple:CharacteristicsClinical examPrescription criteria. Factors:AgeAnisometropiaBinocularityControl of myopic progression

  • Myopia: program IIIDegenerative myopia:CharacteristicsClinical examenPrescription criteria. Factors:Type of optical compensationPseudomyopia:Characteristics Clinical examPrescription criteria

  • Myopia: program IVNocturnal myopia:Characteristics Treatment

  • MYOPIA: GENERALITIES

  • Myopia: Generalities IRefractive condition in which the image of an object at a distance does not form on the retina but focuses in front of the retina. Structural causes of myopia could be:Excessive axial longitude of the eyeExcessive power of the eyeError in the relationship between axial longitude and power

  • Myopia: Generalities IIThe etiology of myopia depends on diverse factors. Such as:HereditaryMagnitudeSexWork NVDietEtc.

  • MYOPIA: CLASSIFICATION

  • Myopia: classification IAccording to the magnitude of the myopia:Low myopia: between -0,25 and -3,00 DModerate myopia: between -3,25 and -6,00 DHigh myopia: between -6,25 and -10,00 DVery high myopia: above -10,00 D

  • Myopia: Classification IIClinically:Simple myopiaMagna, degenerative, or pathological myopiaPseudomyopiaNoctunal myopia

  • Myopia: classification III Most common type of myopiaIs recognized by:Good VA in DV with correction Absence of structural anomalies of the ocular sphere (no pathologies)Retinoscopy subjectiveProgresses limitedlySchool age: 0.50 D/yearAfter 18-20 years of age it has few variationsSIMPLE MYOPIA

  • Myopia: Classification IV Secondary to an excessive axial longitude of the eyeAssociated to alterations or degeneration of certain ocular structuresWith the passage of time the VA can be diminishedAlterations to the posterior pole (mainly):Myopic coneLoosening of the retinaMacular alterationsEtcMAGNA OR DEGENERATIVE MYOPIA

  • Myopia: Classification VPseudomyopiaResult of an accomodative spasmSubjective exam is more negative than the retiniscopyNocturnal myopiaVA reduction in conditions of low illumination

  • MYOPIA: SIMPLE MYOPIA

  • Simple myopia: Characteristics I

  • Simple myopia: Characteristics IIAge School age:At 6 years of age: 5% myopesAt 18 years of age: 25-35% myopes20-60 years of age: stabalization> 65 years of age: do not forget the relationship between nuclear cataracts and myopia

  • Simple myopia: Characteristics IIIPossible risk factors for the development of myopia:Family history of myopiaEmmetropia at pre-school ageAstigmatism against the ruleAltered accomodative functionEndophoria in NVProlonged work in NV and at very short distancesObstruction in the formation of images during the first few years

  • Simple myopia: Symptoms and signsSymptoms Blurry vision in DVRarely symptoms in NVSigns Blinks to reduce the palpebral apertureGood VA in NVMydriasisExodeviationBringing glasses closer

  • Simple myopia : Clinical examRetinoscopy and subjective have similar valueWith the adequate Rx the VA tends to reach 20/20 or even 20/15Absence of related anomalies in the funduscopy.If the subject has never worn glasses he/she could show a reduced amplitude of accomodation for his/her age

  • Simple myopia: Clinical treatment IAge:Children < 2 years of age: hypercorrect by 1-2 DChildren up to 5-years-old (pre-schoolers): hypercorrect by 0,5-1 DFrom 6 to 40 years of age: avoid hypercorrections. Evaluate:Visual needsBinocularity> 40-years-old: Precaution if he/she has never had a myopic Rx before

  • Simple myopia: Clinical treatment IIAnisometropia:Up to 8-10 years of age: try to prescribe for the anisometropia> 10 -12 years of age: prudence in the prescription. Possible existence of monovision

  • Simple myopia: Clinical treatment IIIBinocularity:Exodeviations: Total Rx for general use. In young subjects with exotropia: evaluate a possible slight hypercorrection.Endodeviations: avoid hypercorrections. In NV try a slight hypocorrection

  • MYOPIA: MYOPIA DEGENERATIVE

  • Degenerative myopia: Generalities IElevated myopia associated to pathological degenerative changes mainly in the posterior segment of the eyeAbnormally large axial longitudeOcular complications increase with ageFrequent cause of legal blindness

  • Degenerative myopia: Generalities IIEtiology/risk factors:Family historyPrematurity and low weightAlbinismMental retardationCertain ocular pathologiesAge of beginning:0-5 years of age: 31%6-11 years of age: 61%12 or more years of age : 8%

  • Degenerative myopia: Generalities IIISymptoms: VA in DV, even with the best refraction:From problems in the posterior segmentMinifying effect of the lenses (-)Good VA in NV but at reduced distancesDiscomfort with the glasses:Peripheral distortionWeightChromatic aberrationMinification of the environment

  • Degenerative myopia: Clinical examSigns:Occasionaly exophthalmosVA with the best refractionMore negative retinoscopy than the subjectiveVertex distance critical during the subjectiveAnterior segment:Flatter and thinner corneaMydriasisDeep anterior chamberPosterior segment: relationship cup/disc (in the ophthalmoscopy)Myopic conePosterior staphylomaEtc.

  • Degenerative myopia: Clinical treatmentAvoid hypercorrectionsIf prescribing glasses: control the vertex distanceImportance of prismatic effects in secondary sight positionsContact lenses:Less distorted visionMore accomodative demand in NV

  • MYOPIA: PSEUDOMYOPIA

  • Pseudomyopia: Generalities IValue of the subjective exam is more negative than the that of the retinoscopyPossible spasm of the Ciliary muscleDo not confuse pseudomyopia with myopic hypercorrection

  • Pseudomyopia: Generalities IIEtiology:Spasm of the Ciliary muscle after tasks in NVExodeviationsEffects of medicationInadequate work conditions in NVSymptoms: VA in DV (constant or intermittent)Asthenopia in NV

  • Pseudomyopia: Clinical exam IVA in DVRetinoscopy:Can fluctuateSubjective:More negative than in the retinoscopyThe VA does not justify the refractive changesAccomodation:With the Rx of the subjective it can seem like the amplitude of accomodation is reduced

  • Pseudomyopia: Clinical exam IIBinocularity:Can be associated with exodeviations (secondary condition pseudomyopia)Can be associatated with endodeviations (primary condition pseudomyopia)

  • Pseudomyopia: Clinical treatmentTreatment:Negative minimumIf prescription: use mainly in DVNorms of visual hygieneVisual exercises to relax accomodation

  • MYOPIA: NOCTURNAL MYOPIA

  • Nocturnal myopia: GeneralitiesDiminishment of VA in conditions of poor illumination that improves with contact lensesEtiology:Spherical aberrationDark focus of the accomodation

    Detection depends on the subjects symptomology

  • Nocturnal myopia: Clinical treatmentSpecific Rx for nocturnal activitiesTends to be sufficient with a prescription of -0,75 or -1,00 D

  • MYOPIA: CASES

  • Myopia: case 1-IMT, 13-years-old. Student.MC: Revision. Occasionally notes that he/she does not see well in DVPH: Has never worn glasses. It is his/her first visual revision (previous check-ups by the pediatrician). No illnesses or ingestions of medication.FH: Father and older brother are myopes. Maternal grandmother has cataracts.

  • Myopia: case 1-IINormal VA in DV and NV:RE: 20/30+; NV: 20/20LE: 20/25; NV: 20/20Binocularity in habitual conditions:Cover test:DV: ORTHONV: Low endophoriaPromixal convergence: 6/10cm

  • Myopia: case 1-IIIRetinoscopy:RE: -0,50-0,50x90LE: -50x90Subjective DV and VA:RE: -0,50-0,25x75; VA: 20/20+LE: -0,50x100; VA: 20/20+Habitual amplitude of accomodation:RE: 8cm12,5DLE: 8cm12,5DOcular health tests: within normal limits

  • Myopia: case 1-IVComplete diagnostic of the caseTreatment proposed and plan of revisionsPossible evolution of the condition

  • Myopia: case 1-VComplete diagnostic of the caseLow inverse astigmatism in both eyesLow myopia in REEndophoric tendency in NVThe rest of the tests are within normal limits

  • Myopia: case 1-VITreatment proposed. There are two possibilities:Option A:Do not prescribe glassesRecommend sitting as close as possible to the board in classRecommend rules of visual hygiene: postures and work distanceExplain the condition and desired conduct to the patientRevision in 3-4 months

  • Myopia: case 1-VIITreatment proposed. There are two possibilities:Option B:Prescribe glasses: RE: -0,50-0,25x75; LE: -0,50x100Exclusive use for DV. In class when necessary to in order to pay attention to the board.Do not use the glasses while studying in NVRecommend standards for visual hygiene: postures and work distanceExplain the condition and the desired conduct to the patientRevision in 4-6 months

  • Myopia: case 1-VIIIPossible evolution of the condition:Progression of the myopia

  • Myopia: case 2-ISE, 23 years of age. Salesman.MC: notes that he/she does not see will in DV, mainly while driving.PH: Has worn general use glasses for 10 years. The most recent pair are three-years-old. No illnesses or ingestion of medication.FH: Irrevelant.

  • Myopia: case 2-IIRx and VA are habitual in DV and NV:RE: -2,25; VADV: 20/25-; VANV: 20/20LE: -1,75-0,50x10; VADV:20/30+; VANV: 20/20Binocularity in habitual conditions:Cover test:DV: OrthoNV: Low exophoriaProximal convergence: up to the nose

  • Myopia: case 2-IIIRetinoscopy:RE: -2,75-0,25x180LE: -2,25-0,50x180Subjec