Question

A 65 year old female presents to the clininc complaining, “O cant see well.” She reports halos and glare, especially at night. She has no other complaints and denies any previous intraocular surgery or eye diseases. Past medical and surgical histories are non-contributary. Visual is 20/100 OU best corrected to 20/50 OD and 20/60 OS. Intraocular pressure is 12 mmHg OD by applanation. Slit lamp is remarkable for nuclear sclerosis. Indirect fundus examination is unremarkable. Potential acuity meter yields a best corrected vision of 20/20 OU.

-what is the most likely Dx?

-What is the pathogenesis to this condition?

-What is the treatment of choice?

-List the 2 general types of intraocular lenses that can be implanted and describe their respective properties.

-List the different types of materials used in the past and present to synthesize these intraocular lenses. Why were these materials used and not others?

Answer 1

1) dx means it is a cataract.

2)Halos often show up when you’re in a dim or dark place. Glare is more likely in the daytime. They're a normal response to bright lights, but deeper problems can also bring them on. CAUSES:

Cataracts . Normally, the lens at the front of your eye is clear. Light can pass through easily. A cataract clouds the lens. This blurs your vision and affects the way you take in light. Halos are a common symptom. Glare might make you think that lights are too bright

Common eye problems . Your retina is the thin lining in the back of your eye. It plays a crucial role in vision. If light can’t focus on it, you may start to see halos or glare.

Conditions that can cause this include:

• Nearsightedness (hard to see things that are far away, often worse at night)
• Farsightedness (hard to see things nearby due to the natural shape of your eyeball)
• Presbyopia (hard to see things nearby due to aging)

Astigmatism (blurred vision due to irregular shape of the cornea, the front surface of the eye).

3)1.Vehicle visor. Use this to keep direct sunlight out of your eyes.

2.Lenses. Ask your eye doctor about special types that can help reduce glare and correct eye problems.

3.Fix your vision. ...

4'Get rid of cataracts.

4)Advances in technology have brought about the use of silicone and acrylic, both of which are soft foldable inert materials. This allows the lens to be folded and inserted into the eye through a smaller incision. Specifically, acrylic lenses are a better choice in people who have a history of uveitis, or are likely to have to undergo retinal surgery requiring vitrectomy with replacement by silicone oil, such as persons with proliferative diabetic retinopathy or who are at high risk of retinal detachment, such as persons with high myopia. A study found that in participants with a history of uveitis, eyes treated with hydrophobic acrylic IOLs were over 2 times more likely to have a best corrected visual acuity of 20/40 or more, compared to eyes treated with silicone IOLs.

5)the various materials which have been used to manufacture intraocular lens implants include polymethylmethacrylate (PMMA), silicone, hydrophobic acrylate, hydrophilic acrylate and collamer. Polymethylmethacrylate (PMMA) was the first material to be used successfully in intraocular lenses. British ophthalmologist Sir Harold Ridley observed that Royal Air Force pilots who sustained eye injuries during World War II involving PMMA windshield material did not show any rejection or foreign body reaction. Deducing that the transparent material was inert and useful for implantation in the eye, Ridley designed and implanted the first intraocular lens in a human eye.

Advances in technology have brought about the use of silicone and acrylic, both of which are soft foldable inert materials.