Ophthalmologic Applications

Question 1

Age related eye diseases

Answer 1

• Cataracts: clouding of the lens, requires removal (treated with intraocular lens/IOL implant)
• Glaucoma: blockage of drainage, leading to increased pressure in eye and death of retinal/nerve cells (pharmacologic or shunt intervention)
• Age-related macular degeneration
• Diabetic retinopathy

Question 2

Correctable vision issues

Answer 2

• Myopia: near-sightedness, light focuses in front of retina
• Hyperopia: far-sightedness, light focuses behind the retina
• Astigmatism: cornea is no longer spherical
• Presbyopia: loss of ability of lens to focus on nearby objects

Question 3

Ophthalmic Material Considerations

Answer 3

• Standard biocompatibility, stability/degradation, sterilization
• Transparency, including refractive index
• UV-blocking to protect retina
• Oxygen and nutrient transport to protect corneal health

Question 4

Contact lens considerations

Answer 4

• correct focus of light onto the retina, transmitting about 100% of visible light
• highly wettable surface
• oxygen transmissibility
• hard/soft segments:
  hard: PPMA with silicone and fluorine-containing macromers, increasing oxygen permeability
  soft: PHEMA with NVP and other add-ins to increase water content and thus oxygen permeability

Question 5

Refractive Power of the eye

Answer 5

• 70% of the eye’s refractive power is from the cornea, while the lens provides the rest
• when relaxed, zonule ligaments attached to the ciliary muscle place the capsular bag/lens sac, and thereby the lens, under tension for far-sighted vision, relaxing for near-sighted (study diagram)

Question 6

Intraocular lens (IOL) implants

Answer 6

• 3 mm incision with insertion of foldable IOL into capsular bag, which housed prior lens and is attached to zonules
• currently use silicone- or hydrophobic/hydrophilic acrylate based
• short-term functionality, long-term reduction of posterior capsule opacifying
• flexible haptics to prevent IOL rotation