NOBC 2025 SESSION G - KNOWING YOUR IOL

1. Regarding focal point

• A. It is the point where light rays originating from a point on an object converge in the eye

• B. Focal point in meters is reciprocal of the pre-operative refraction in diopters

• C. Postoperative outcome can be optimized by targeting specific focal points

• D. Sharp vision without glasses post cataract surgery is attained if the focal point is aimed at +/-0.25D to +/-0.5D

Answer explanation

B. False: Focal point in meters is reciprocal of the postoperative refraction

2. The followings is/are true in choosing a refractive target after cataract surgery

• A. Always aim for emmetropia

• B. Patient desire is the key factor in choosing refractive target

• C. It should be tailored to individual requirements and lifestyle

• D. Patient’s preoperative refractive status is not a consideration

Answer explanation

A. False: Emmetropia is not necessarily the desired outcome

D. False: Patient’s preoperative refractive status need to be considered

3. 3. Regarding Toric IOL

• A. Optical power and focal length are perpendicular to each other

• B. IOL has ability to correct astigmatism

• C. Bitoric surface IOL had higher range of cylinder correction

• D. Haptic plate is more susceptible to compression

Answer explanation

D. Haptic plate is less susceptible to compression

4. Regarding multifocal IOL

• A. It separate the light into different foci

• B. It allow individuals to see clearly at different distances

• C. Different rings in refractive multifocal IOL create multiple focal points

• D. It has potential for halos and glare

5. 5. Regarding modern monofocal IOL

• A. Square edge features increase the rate of PCO

• B. Biconvex surface reduce the optic thickness

• C. Aspheric properties reduce spherical aberration

• D. Hydrophobic IOL reduce the rate of PCO

Answer explanation

A. False. Square edge IOL reduce the rate of PCO