Contact Lens 2 RBE

The reduction of Oxygen supply on an organ is called:

Hypoxia

Absence of Oxygen on an organ is called:

Anoxia

HCL is more susceptible to deposits compared to SCL. True or False?:

False

The following are effects of hypoxia EXCEPT:

Increase in epithelial mitosis

Oxygen supply percentage on the cornea during waking hours:

21%

Percentage of corneal swelling overnight:

3-4%

Oxygen percentage needed for the cornea to avoid swelling:

More than 8 %

Oxygen percentage required to prevent the mitosis of epithelial cells and to prevent accumulation of lactate:

13%

Oxygen percentage required to prevent loss of corneal sensitivity:

8%

The most severe type of contact lens complication wherein there is pain, severe injection, corneal and lid edema, anterior chamber reaction, stromal and epithelial corneal involvement:

Microbial keratitis

The most common organisms in contact lens related ulcers:

Pseudomonas and serratia

The minimum Dk/L for contact lens to avoid detectable swelling is called:

Critical oxygen requirement

The minimum Dk/L for an Ideal DW so that there will be no corneal swelling is:

87 X 10 –9

Ideal EW value:

87 X 10 – 9

clouding of the epithelial tissue, usually centrally, with associated punctate epithelial staining, steepening of the corneal curvature and possible irregularity of the corneal surface is called:

Epithelial edema

The following are the treatment for epithelial edema EXCEPT:

Increase wear time

Fine wrinkling on the descemet’s membrane during stromal edema is called:

Striae

Tiny cystic bodies that contains cellular debris:

Microcysts

Cystic bodies that are fluid-filled:

Bullae

Neovascularization wherein there is Sectorial or circumlimbal vessel extension 0.5 to 1.5 mm into cornea:

Grade 2

Neovascularization wherein there is Sectorial or circumlimbal vessel extension more than 2.5 mm into cornea, or any one vessel to within 3 mm of corneal apex:

Grade 4

Neovascularization wherein there is Sectorial or circumlimbal vessel extension 1.5 to 2.5 mm into cornea:

Grade 3

The following statements are true about acute tight wear syndrome EXCEPT:

Microbial toxins do not play a role in creating the inflammatory response

The following are seen in the diagnosis of tight wear syndrome EXCEPT:

Maximal epithelial staining

It is a localized collection of white blood cells with an excavated area on the cornea that has undergone necrosis due to immulogical invasion:

Sterile infiltrates

The diagnosis for soft lens dessication/dryness is:

all of the above

The diagnosis for soft lens dessication will most likely be:

Inferior arcuate punctuate staining

A severe manifestation of chronic peripheral corneal desiccation. Over time, the affected areas develop infiltration, neovascularization, and epithelial and stromal hypertrophy. This results in a cloudy elevated lesion that often stains with fluorescein:

Vascularized limbal keratitis

The following statements are TRUE about risk factors for CL complication EXCEPT:

CLs are much thinner than tear film

Amount of oxygen required by the cornea to maintain corneal thickness, metabolism, and sensitivity:

Between 8 to 21 percent

The following statements are advantages of MONOVISION EXCEPT:

Specialty lens designs are required

The following statements are disadvantages of MONOVISION EXCEPT:

Increased stereopsis

The following are ways to determine the dominant eye EXCEPT:

pinhole test

The following statements are true about MULTIFOCAL CL EXCEPT:

No need of visual compromise in both eye

The first and most common stabilization technique in toric contact lenses is:

Prism ballast

the stabilization technique that removes as much prism as possible from a lens through 360 degree comfort chafers which reduces thickness of the lens:

peri-ballast

the following statements are true about dynamic stabilization technique EXCEPT:

A significant additional thickness of the lens will be required

Given: OD – 1.00DS/-1.00cylx180; Trial CL Power: 0.00DS/-1.00cylx180, lens rotates 10 degrees to the left, what will be the final rx axis to be prescribed?

170

Given: OS – 2.00 DS/-1.50cyl x 90; trial CL power: -1.00DS/-1.25x90, lens rotated 15 degrees to the left, what will be the final rx axis to be prescribed?

105

Given: OD -1.50 DS/-1.00 cyl x 15; trial cl power: OD -1.00/1.00 cylx15, there was no observable rotation of the lens, what will be the final rx axis to be prescribed?

15

A multifocal lens design in which light through both distance and near optics is imaged on the retina at the same time:

simultaneous

A multifocal contact lens system in which there are two distinct power zones in the lens, and in which the patient views through one or the other, depending upon the position of gaze:

alternating

Which of the following prescription best approximate a toric prescription for a subjective refraction of -2.00 sph/-2.00 cyl x 180 and the lens rotates 10 degrees to the right.

-2.00 sph/-2.00 cyl x 170

Which of the following prescription best approximate a toric prescription for a subjective refraction of -4.50sph/-1.00 cylX 10 and the lens rotated 5 degrees to the left?

-4.50 sph/ – 0.75 cyl x 15

Which of the following prescription best approximate a toric prescription for a subjective refraction of -5.00 sph/-1.25 cyl x 90 and the lens rotated 5 degrees to the left:

-4.75 sph/ - 1.00 cyl x 95

Which of the following prescription best approximate a toric prescription for subject refraction of -1.75sph/-0.75cylx170 and the lens rotated 12 degrees to the left:

-1.75 sph/-0.75 cyl x 2

The following statements are true about keratoconus EXCEPT:

Non-inflammatory, self-limiting ectasia of the axial portion of the cornea

The best instrument to diagnose keratoconus is the:

Photokeratoscope

The tear-drop configuration seen in the central rings of a patient with keratoconus is called:

Keratoconus

The following statements are true about Scleral/Haptic lenses for keratoconus EXCEPT:

Historically the first type of contact lenses fitted and were commonly used for keratoconus.

An oval type of keratoconus is when:

Large diameter and often displaced inferiorly; greater than 5 mm

The following statements are true about ortho-keratology EXCEPT:

Redistributes basement cells of the corneal epithelium to flatten the central corneal shape

Ortho-keratology is effective in astigmatism with power of:

Approximately 2.00 Diopters of astigmatism

The following are factors that affect the effectivity of ortho-keratology EXCEPT:

No exception

The following are risks of ortho-keratology EXCEPT:

Mild abrasion

Risk of ortho-keratology may slightly increase because of:

Overnight use

Which of the following are good candidates for Ortho-keratology?

Athletes

The following statement/s is/are true of corneal power:

Corneal power cannot be created but redistributed

Subjective refraction -4.00 sph/ -2.00 cyl x180; K reading = 43.00@180/44.00@90

The residual astigmatism is:

-1.00 cyl x 180

Subjective refraction -4.00 sph/ -2.00 cyl x180; K reading = 43.00@180/44.00@90

The corneal astigmatism is:

-1.00 cyl x 180

Subjective refraction -4.00 sph/ -2.00 cyl x180; K reading = 43.00@180/44.00@90

The total astigmatism is:

-2.00 cyl x 180

Subjective refraction -4.00 sph/ -2.00 cyl x180; K reading = 43.00@180/44.00@90

The best toric design for the above powers will be:

Bitoric

Subjective refraction: - 2.00 sph / - 1.50 cyl x 180; K reading = 44.00@180/ 44.00@90

The residual astigmatism is:

-1.50 cyl x 180

Subjective refraction: - 2.00 sph / - 1.50 cyl x 180; K reading = 44.00@180/ 44.00@90

The corneal astigmatism is:

plano

Subjective refraction: - 2.00 sph / - 1.50 cyl x 180; K reading = 44.00@180/ 44.00@90

The total astigmatism is:

-1.50 cyl x 180

Subjective refraction: - 2.00 sph / - 1.50 cyl x 180; K reading = 44.00@180/ 44.00@90

The best toric design for the above powers will be:

Front toric

Subjective refraction: 0.00 S -1.00 cyl x 180; k reading : 45.00@180/46.00@90

The residual/internal astigmatism is:

Plano

Subjective refraction: 0.00 S -1.00 cyl x 180; k reading : 45.00@180/46.00@90

The corneal astigmatism is:

-1.00 x 180

Subjective refraction: 0.00 S -1.00 cyl x 180; k reading : 45.00@180/46.00@90

The total astigmatism is:

-1.00 x 180

Subjective refraction: 0.00 S -1.00 cyl x 180; k reading : 45.00@180/46.00@90

The best toric design for the above powers will be:

back toric

A presbyopic patient has a prescription of OD +1.50 OS +1.00 add OU 2.00 with dominant eye=OS and was recommended for some contact lens prescription. What would be the powers of the lenses for the following options:

Far Contact lens with near Spectacles:

b. Contact Lens (far): OD +1.50 OS +1.00; Reading glasses (near): OU +2.00

A presbyopic patient has a prescription of OD +1.50 OS +1.00 add OU 2.00 with dominant eye=OS and was recommended for some contact lens prescription. What would be the powers of the lenses for the following options:

Near Contact lens with Far Spectacles:

a. Spectacles (far): OU -2.00 Sph; Contact Lens (near): OD +3.50; OS +3.00

A presbyopic patient has a prescription of OD +1.50 OS +1.00 add OU 2.00 with dominant eye=OS and was recommended for some contact lens prescription. What would be the powers of the lenses for the following options:

Monovision:

b. Contact lens OD +3.50; OS +1.00

A presbyopic patient has a prescription of OD +1.50 OS +1.00 add OU 2.00 with dominant eye=OS and was recommended for some contact lens prescription. What would be the powers of the lenses for the following options:

Multifocal:

b. Multifocal contact lens: OD +1.50 add hi; OS +1.00 add hi

A presbyopic patient has a prescription of OD +1.50 OS +1.00 add OU 2.00 with dominant eye=OS and was recommended for some contact lens prescription. What would be the powers of the lenses for the following options:

Modified Multifocal:

c. OD: multifocal contact lens: +1.50 add med; OS single vision CL : +1.00

If the spectacle power is -4.00 sph; what will be the effective power if it is to be prescribed as a contact lens?

-3.75

If the spectacle power is -5.50 sph; what will be the effective power if it is to be prescribed as a contact lens?

-5.25

If the spectacle power is -6.50 sph -1.50 cyl x 180; what will be the effective power?

-6.25 sph – 1.50 cyl x 180

As a general rule, a lens with plus power that is moved closer to the eye will:

Gain power

As a general rule, a lens with minus power that is moved closer to the eye will:

Lose power

If the primary consideration of a patient in contact lens wear is comfort above all, which of the following contact lens option would you suggest to the patient:

Soft contact lenses

If the primary consideration of a patient in contact lens wear is for better optics and some form of myopia control, which of the following contact lens option will best fit the patient?

Hard contact lenses

Best contact lens option for athlete with previous noncompliance:

Daily disposable soft contact lenses

Best option for 12-year-old progressing myopia:

Conventional RGP/Hard contact lenses

The last step an optometrist does in terms of dealing with the patient is:

Aftercare

The usual aftercare schedule for new contact lens wearers should be:

7 days after

Bioric contact lens design is best suited for:

Some of the patient’s astigmatism lies on the cornea while some lies residually

Front toric contact lens design is best suited for:

All of the patient’s significant astigmatism lies on the anterior cornea and none residually

When the total astigmatism is equal to the corneal astigmatism and the residual astigmatism is equal to zero, what would be the best toric design?

Back toric

When the corneal astigmatism is not equal to zero and the residual astigmatism is also not equal to zero, what will be the best toric design for the patient?

Bitoric

Particles trapped under contact lens can result in damage on what layer of the cornea:

Epithelium

Which type of infection has a greater possibility when large abrasions on the cornea caused by contact lens wear:

Gram negative

Abrasion by foreign body is more common in this type of contact lenses:

rgp or hard contact lens

These are air bubbles trapped underneath contact lens which appears as dot “staining” under floursecein:

Dimple veiling

The primary reason for when there is contact lens adhesion is:

Poor fitting relationship

The following are symptomatology of contact lens adhesion EXCEPT:

increased wearing time if RGP

An acute splitting of the corneal epithelium due to chronic mechanical stress exacerbated by tight fitted soft contact lenses:

Superior epithelial arcuate lesion

A soft contact lens patient reporting initial comfort, then discomfort after several minutes or hours, and upon slit lamp examination the fit is seen to be tight through push up test, the discomfort may be due to:

steep base curve

If a soft contact lens patient reports immediate discomfort, with excessive movement and observable decentration, the discomfort may be due to:

Flat base curve

If you will be seeing complications secondary to mechanical origins, the best course of action in treating should begin with:

Discontinuing contact lens wear