This document summarizes various errors of refraction and accommodation, including definitions of emmetropia and ametropia. It describes myopia in detail, outlining types like simple myopia, developmental myopia, and pathological myopia. It discusses changes that occur in high myopia, including posterior staphyloma and retinal degenerations. Symptoms and treatment options for myopia are provided, with more in-depth explanations of radial keratotomy, photorefractive keratectomy, and LASER in-situ keratomileusis procedures. Hyperopia, astigmatism, aphakia, presbyopia, anisometropia, and anomalies of accommodation are also briefly outlined
This is a seminar presentation conducted by 4th year medical student under supervision of a lecturer. This is for ophthalmology posting seminar. Source of information are from google, few textbooks and also based on previous ophthalmology posting group's seminar.
This is a seminar presentation conducted by 4th year medical student under supervision of a lecturer. This is for ophthalmology posting seminar. Source of information are from google, few textbooks and also based on previous ophthalmology posting group's seminar.
Retinoblastoma (RB) is a rare form of cancer, that rapidly develops from the immature cells of a retina ( the light-detecting tissue of the eye). It is the most common primary malignant intraocular cancer in children.
Cancer of the Eye
Diagnosis: Birth-~6 years olds
Unilateral or Bilateral
~3% of Pediatric Cancers
Retinoblastoma (RB) is a rare form of cancer, that rapidly develops from the immature cells of a retina ( the light-detecting tissue of the eye). It is the most common primary malignant intraocular cancer in children.
Cancer of the Eye
Diagnosis: Birth-~6 years olds
Unilateral or Bilateral
~3% of Pediatric Cancers
MYOPIA , basics , causes , types and treatmentssuserde6356
Myopia, also known as near-sightedness and short-sightedness, is an eye disease[5][6][7] where light from distant objects focuses in front of, instead of on, the retina.[1][2][6] As a result, distant objects appear blurry while close objects appear normal.[1] Other symptoms may include headaches and eye strain.[1][8] Severe myopia is associated with an increased risk of macular degeneration, retinal detachment, cataracts, and glaucoma.[2][9]
Myopia results from the length of the eyeball growing too long or less commonly the lens being too strong.[1][10] It is a type of refractive error.[1] Diagnosis is by the use of cycloplegics during eye examination.[11]
Tentative evidence indicates that the risk of myopia can be decreased by having young children spend more time outside.[12][13] This decrease in risk may be related to natural light exposure.[14] Myopia can be corrected with eyeglasses, contact lenses, or by refractive surgery.[1][15] Eyeglasses are the simplest and safest method of correction.[1] Contact lenses can provide a relatively wider corrected field of vision, but are associated with an increased risk of infection.[1][16] Refractive surgeries like LASIK and PRK permanently change the shape of the cornea. Surgeries like Implantable Collamer Lens (ICL) implant a lens inside the anterior chamber in front of the natural eye lens. ICL doesn't affect the cornea.[
This presentation describes all the clinical aspects of keratoconus management
You can watch the illustrated presentation in this link :
https://www.youtube.com/watch?v=pYxwZPGm7e4&list=PLZ_mM13I_TrhWavjTmE9NjW1O5bGxkONO&index=13
7. MYOPIA
Simple myopia upto 5D
Developmental myopia –10D at birth
Pathological axial myopia: starts at 5-10 yr of age
and gors on increasing till 25 . May achieve 15-
25D or more.
Pathological curvature myopia. K.conus
Index myopia i.e. nuclear sclerosis, DM, drugs:
Hydralazine, chlorthalidone and phenothiazines.
8. CHANGES IN MYOPIA
Axial myopia affects post. half more oftenly and
adversely as compared to ant half.
Post staphyloma
Myopic crescent
Peripheral retinal degenerations leading to
thinning, hole formation and ret. detach.
Mac. Hole. Vitreous degeneration:
Choroidoretinal atrophy, laquer’s crackes, ch
small vessel haemorrhages and thrombises leading
to Foster-Fuchs spot.
9.
10.
11.
12.
13.
14. CHANGES IN MYOPIA--- CONTINUED---
Eyes look prominent, AC deep and pupils wide.
Pseudoesotropia. Poor visual acuity in spite of
optical correction.Centra/peripheral scotomas.
Pre-senile cataract, increased prevalence of
POAG, PDS/PDG,steroid responsiveness.
Marfan’s, Stickler, Ehlers-Danlos and Pierre-
Robin----Syndromes.
15. SYMPTOMS
Indistinct distant vision.
Disproportionate accommodation and
convergence may lead to discomfort in near
work.(High myopia)
Black spots and flashes in front of eye.
17. RADIAL KERATOTOMY
PROCEDURE:
Multiple deep stromal radial cuts starting from optical
zone (Central 4mm) up to limbus by diamond knife.
Causes bulging of peripheral cornea and flattening of the
central.
INDICATIONS:
Static myopia upto 5D of adults with no or little
astigmatism.
CONTRA-INDICATIONS:
Before 21 year of age, significant astigmatism and
corneal opacity.
18. RADIAL KERATOTOMY cont..
SUCCESS RATE:
50% stable by about six month.
PER-OPERATIVE COMPLICATIONS:
Accidental perforation, involvement of visual
axis and incisions of wrong direction.
POST -OPERATIVE COMPLICATIONS:
Bacterial keratitis, endophthalmitis,
introstromal inclusionst, globe rapture and cataract
formation.
19.
20. PHOTOREFRACTIVE KERATECTOMY
PROCEDURE:
Optical zone anterior stromal ablation by Excimer Laser
after de- epithelial removal. This thins central cornea and
reduces is by diaptoric power.
INDICATIONS:
Static myopia upto 6D , astigmatism upto 3D.
CONTRA-INDICATIONS:
High astigmatism and myopia more than 7D.
21. PHOTOREFRACTIVE KERATECTOMY cont..
SUCCESS RATE:
90% achieve final refractive error of 1D. Long
term drift especially in high myope.
COMPLICATIONS:
Mild pain and watering for few days. Corneal
scarring 3% of cases. Night glare.
22.
23.
24. LASER IN-SITU KERATOMILEUSIS
PROCEDURE:
Same as PRK except that laser is applied after a hinged
corneal flap by micro keratome.
INDICATIONS:
S myopia upto 12D , astigmatism upto 5D.
CONTRA-INDICATIONS:
Eyes with thin cornea.
25. LASER IN-SITU KERATOMILEUSIS cont..
SUCCESS RATE:
Results are better than PRK.
COMPLICATIONS:
Buttonholing, amputation, incomplete irregular
flaps and corneal perforation.
Wrinkling, distortion or dislocation of flap.
Epithelial in growth under flap. Keratitis, anterior
segment ischaemia and optic neuropathy.