Myopia

Question 0

.Pseudomyopia - Def

Answer 0

Sudden appearance of myopia

Acc spasm from prolonged near work, stress, etc.

Question 1

.Max amount of myopia progression expected in adult-onset myopia

Answer 1

-1.00

Maybe -2.00 if already an existing myope

Question 2

.Signs of pseudomyopia

Answer 2

• Decreased dVA
• Decreased acc amp
• Miosis
• Eso
• Decreased results of any test req relaxation of acc (e.g. NRA)
• Decreased myopia w/ cycloplegic

Question 3

.Relationship btwn eye length and P

Answer 3

Every 1mm of increase in axial length results in 3 D of myopia

Question 4

.Conclusion if VA improves vs. stays the same w/ pinhole

Answer 4

Improves
if vision loss due to RE (or change in media, e.g. cataract)

Same
if due to physiological reasons (e.g. retinal damage)

Question 5

.How to choose Rx to give, based on old and new amounts

Answer 5

Max plus to max VA

w/ one line of improvement rule w/ each -0.25D

Question 6

.Just Noticable Difference (JND) expected

Answer 6

Letter size
-> Move decimal over to L two places

20/50 -> See +/-0.50

Question 7

.Media that supply ref P

Answer 7

Cornea
- Provides 2/3 of P

Lens
- Provides 1/3 of P

Question 8

.Prevalence of myopia based on age

Answer 8

< 2% entering kindergarten
> 15% entering HS
25% adults

Question 9

.Health-related reasons for myopic shift

Answer 9

Nuclear cataract
Diabetes (-1.50)
Pregnancy
Corneal edema

Drug-induced (esp sulfa drugs)

Degenerative myopia
(> -6.00)

Question 11

.Juvenile vs. Adult-onset myopia

Answer 11

Onset btwn 8-12 years

vs.

Onset btwn mid-20s to mid-30s
Late > 40

Question 13

.Night myopia - Def

Answer 13

Difficult seeing far at night