gradual loss of vision (cataract)

Question 1

conditions that cause loss of vision gradually

Answer 1

usually chronic degenerattive , chronic disorders in the elderley

less common disorders include inhertied disorders of the retina or optic nerve such as retintis pigmentosa

Question 2

types of conditions that cause sudden loss of vision

Answer 2

vascular and inflammatory dirosders

sometimes patients suddenly nptice a profound loss of vision that has actually been developing gradually

Question 3

common causes of grdual loss of vision in the elderley

Answer 3

cataract

chronic open angle glaucoma

macular degeneration

or any combination of all three

Question 4

gradual loss of vision in the eldelry patient common causes

Answer 4

catarct

chronic open angle glaucoma

macular degeneration

Question 5

define catatract and presybyopia

Answer 5

Cataract is the name applied to any opacity or clouding in the lens
The lens formed from surface ectoderm
It continues to enlarge through life
Change in lens shape allows accommodation (focussing for reading)
Loss of ability to change shape is called presbyopia (onset during 5th decade)

Question 6

describe the structure of the lens

Answer 6

The lens is avascular
It lies behind the iris
It is attached to the ciliary muscle by the zonules
It is made up of fibres derived from the anterior lens capsule
The nucleus is the oldest part of the lens
Fibres are continuously added around the nucleus throughout life, forming the cortex

Question 7

charcateristics of cataract

Answer 7

They are often bilateral
All ages (even congenital) can be affected but they are usually age related
They can be associated with many syndromes (e.g. Down’s syndrome) but the majority are an ageing phenomenon
The prevalence of cataract is 90% over 80 years

Question 8

white colour of the pupilin adavnaced stage of cataract

Answer 8

leucocoria

Question 9

three types of cataract

Answer 9

cortical

nuclear

subcapsular

Question 10

what is the progression of nucelar cataract with age asscoated with

Answer 10

associated with increased pigment discolouration

Question 11

christimas tree cataract are called

Answer 11

polychromatic opacities in the lens

Question 12

posterior subcapsular catract charcaterisitcs

Answer 12

Patients with this type of central cataract have good vision when the pupil is dilated e.g. in dim illumination
In bright light the pupil constricts and vision is profoundly reduced

reduced cv - especially blue

Question 13

cortical cataract charcaterstics

Answer 13

Patients have good vision , may report glare , lights , halo can cause diplopia

Question 14

cataract caused by a blunt injury to the eye looks like

Answer 14

This ‘sunflower’ cataract has been caused by a blow to the eye
The lens has also been knocked out of place because of damage to the zonules

Question 15

congenital (zonular catarcat is caused by)

Answer 15

In this child the central part of the lens is opaque
Visual acuity can often be good so that surgery can be delayed until the child is visually mature (age 8-9 yrs)
Dense congenital cataracts in neonates require urgent attention to avoid amblyopia

Question 16

what are some of the causes of secondary catract

Answer 16

Associated with other ocular disease
Associated with medical treatments
Associated with systemic conditions

Question 17

catarcat is also associated with what other eye diseases

Answer 17

Heterochromic cyclitis
Iris colour, KP, vitreous abnormalities
Iritis
Aniridia
Retinitis pigmentosa
Iron intraocular foreign body

Question 18

what other treatment are associted with catarcat

Answer 18

Steroids-topical and systemic
Glaucoma treatment
Radiation
Vitreous surgery
Antipsychotic drugs

Question 19

what systemic ilness is associated with cataracts

Answer 19

Metabolic
Diabetes, galactosaemia, hypocalcaemia, Wilson’s disease, myotonic dystrophy
Skin disease-atopy
Genetic
Down’s, Alport’s, Lowe’s syndromes etc
Infection (maternal)
Rubella, CMV, syphilis

Question 20

what symptoms are associated with cataracts

Answer 20

Cataracts can remain asymptomatic for years
Nuclear cataracts lead to myopia (short-sightedness) which can improve reading vision
Eventually visual acuity is reduced
Cortical cataracts cause glare, haloes and occasionally double vision
Posterior subcapsular cataracts cause poor vision in bright light
Loss of colour vision (especially to blue light) can cause problems e.g. artists

Question 21

cataract surgery indications

Answer 21

The decision to operate is based upon an assessment of the impact of the lens opacity on daily life for each patient
Most surgery is performed under local anaesthesia
Day case surgery is appropriate for over 95% of patients

Question 22

phacomeulsification process

Answer 22

Phacos = lens
Emulsification = fragmentation of lens fibres using ultrasound
The technique allows a small, self-sealing incision that does not require sutures
As the natural lens is removed the patient would be left with a high refractive error (usually needing a +12 dioptre lens)
This is avoided by the insertion of intraocular lens (implant)
Rapid visual rehabilitation (within 24 hours) is normal

Question 23

cataract sx steps

Answer 23

sloping incision made peripheral conrea

incision = self sealing

circular opening made in anterior capsule of lens

lens removed using a probe - probe has 3 functions

ultrasonic pharmacemulsification

irrigation (saline)

aspiration of the lens material)

cortical lens remennts are removed by aspiration and irrigation until a clear bag is created to support the IOL implant

Question 24

catarct sx problems

Answer 24

Most surgery is free of complications -95%
Intraoperative problems
The lens capsule may rupture which leads to vitreous prolapse and a ‘dropped’ nucleus,
Intraocular haemorrhage can be severe
Postoperative problems
Intraocular lens dislocation
Capsule opacification
Intraocular infection-endophthalmitis
Severe inflammation

Question 25

what would you see in an intraouclar lens disolcation

Answer 25

subluxated implant

edge of implantt is visible in the pupil

Question 26

what is complete intraouclar lens disocattion

Answer 26

As the lens is no longer in the visual axis the patient has poor vision
In this illustration the blue supporting leg (haptic) of the lens is visible

Question 27

capsule opacification is caused by what

Answer 27

common. delayed complication of surgery

As the lens is no longer in the visual axis the patient has poor vision
In this illustration the blue supporting leg (haptic) of the lens is visible

Question 28

endopthalmitis

Answer 28

red painful eye with reduced vision

during the first post operative week

requires urgent intraocular antibiotics to prevent permeant loss of vision

Question 29

nuclear cataract symptoms

Answer 29

leads to myopia

can improve reading

va is reduced

Question 30

clinical characteristics of catarcta

Answer 30

leucoria

opacities