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K's 42.50@180/40.50@90
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Question | Answer |
---|---|
What term refers to sensitivity to light | Photophobia |
The following is an example of what type of astigmatism K's 42.50@180/40.50@90 | Against the rule astigmatism |
What medication they affect successful contact lens wear | Antihistamines |
The cornea receives nutrients from what | Limbal blood vessels |
The increased loss of ability of the crystalline lens to accommodate is called | Presbyopia |
What instrument can provide simultaneous information about the cornea, lids, conjunctiva, lashes, contact lens surface and fit | Slit lamp |
The pre-corneal tear film is composed of three layers what are they | Lipid, aqueous, mucin |
Transpose the following Rx -4.50 +1.25 x 94 | -3.25 -1.25 x 4 |
The average pH value of the human tear is | 7.4 |
If the manufacturers guidelines suggest a minimum of four hours for disinfection what would you suggest to the patient | A minimum of four hours is required |
The main supply of oxygen to the corneal epithelium is derived from the | Tear film |
What is the term for the condition in which there is a loss of vision without any apparent disease to the eye | Amblyopia |
Which auxiliary trial lens will extend the keratometer to approximately 30.00D | -1.00 |
Which step should be performed first when taking Keratometer measurements | Focus the eyepiece |
The following is an example of what type of astigmatism 44.00@180/44.50@90 | Lenticular astigmatism |
What are ocular signs of aging | Tear film abnormalities, reduced with elasticity, lens opacites, loss of accommodation |
Transpose the following RX and two minus cylinder form +1.50 +1.00 x 75 | +2.50 -1.00 x 165 |
The pre-corneal tear film provides what | A smooth optical surface and metabolic nutrients to the epithelium |
Name the five cornea layers in order from front to back | Epithelium, Bowmans membrane, stroma, decrement a membrane, endothelium |
The normal cornea is transparent due to the pump action creating proper fluid balance. Which layer of the cornea is most responsible for maintaining this function | Endothelium |
A normal tier break up time is what | 10-12 seconds |
A whitish Hayes in the peripheral corneal stroma which does not stain and is often seen in the elderly is known as | Arcus senilus |
Patients with keratitis sicca are more prone too | Secondary infection |
Upon removal of the crystalline when's the patient is | Aphakic |
The following rx represents OD +2.00 = 20/20 OS -3.00 -2.00 x 180 = 20/20 | Anisometropia |
OD +2.00 = 20/20 OS -3.00 -2.00 x 180 = 20/20 The above patient will best achieve stereopsis with which of the following modalities | Contact lens |
Tom spectacles with a power of -12.00+.50Ã96 sits 10mn in front of his cornea the likely soft contact lens prescription for Tom would be what | -10.50 |
The Keratometer is a instrument used to measure | Corneal curvature |
An instrument used to evaluate corneal irregularity by reflecting concentric circles from the patients cornea is called | Placido disk |
What auxiliary trial ends will extend the keratometer to approximately 61.00D | +1.25 |
Wearing lenses in high altitude's and dry environments may result in complaints in all areas except photophobia, grittiness, burning sensation, chalazion | Chalazion |
Patients with which of the following occupations can successfully wear contact lenses Arc welder, teacher, firefighters, all of the above | All of the above |
Transient keratometric mire distortion is usually due to what | Irregular corneal astigmatism |
In against the rule astigmatism the steepest corneal Meridian is | Is at or near 180° |
Irregular mires on a keratometer maybe indicative of | Dry eye or excessive mucoid secretion Contact lens induced corneal warpage Keratoconus |
In an alignment lid attachments RGP fit the fluorescein pattern should show | A thin even layer of fluorescein in less than 180° of bearing in the mid-periphery |
In a RGP wearer, an acute stain on the cornea may be due to | Poorly blended secondary curves |
What is schirmer I test | A patient with an unanestgetized eye and normal tear output should wet at least 15 mm of the filter paper in five minutes |
What is schirmer II test | And Anesthetic drop is instilled before the schirmer strip is inserted to eliminate the reflex tearing caused by the filter paper |
Rose bengal testing | Will stain devitalize conjunctival epithelial cells brightly |
When evaluating tear film break up time | A break up time of less than 10 seconds may preclude success with contact lenses |
The preservative in contact lens solution does what | It is formulated to keep micro organisms from multiplying in a bottle of contact lens solution after it is opened |
A patient wearing a high horizontal prismatic correction for motility problem | May experience diplopia when fit with contact lenses |
A pre-presbyopia myopic patient who is still able to read with single vision glasses may find that | They are unable to see fine print when wearing contacts |
Amy's +8.50 D spectacles sit at 12mm from the cornea. The power of a soft contact lens dory Amy. Properly vertex would be | +9.50 |
What would work best for this patients visual needs, given the following information K's 42.00@180/43.00@90 -2.00 -1.00 x 180 | Spherical soft lens |
Which of the following set of lens specifications would beat simulate and intrapalpebral RPG fitting given the following information 42.00@180/43.00@90 -2.00 -1.00 x 180 Upper lid positions 2 mm above the superior limbus | 42.50 -2.50 8.5 |
Which contact lens would beat correct this patients visual needs given the following information 46.00@180/44.50@90 -3.00 -1.50 x 90 | A soft toric lens |
What contact lens material components has the highest gas permeability | Silicone |
When documenting in a pts chart on a new fitting recheck what is not necessary | Sisters lens type that caused her problems |
Application of fluorescein should be used in what situation | Evaluation of a rigid gas permeable lens fit |
If the diagnostic rigid gas permeable lens placed on the eye results in minimal movement what would increase the movement on the lens ordered for the patient | Decreasing lens diameter |
If a soft contact lens decenters laterally exposing a portion of the patients limbus what change in perimeter would improve the situation | Decreasing the lens diameter |
When evaluating a diagnostic soft lens on a patient, you notice that movement is sluggish after only a few minutes which of the following changes would you make to the lens that are ordered for the patient | Flatten the base curve |
Which of the following lens designs would provide the best visual result for this patient 43.00 @ 180 / 46.00 @ 90 -3.00 Sphere | Soft spherical lens |
Which edge design is recommended for 8+15.00 D aphakic RGP lens | Lenticular myoflange |
Which of the following lens design would provide the best visual result for this patient 42.00 @ 180/ 42.50 @ 90 -3.50 -1.75 x 180 | Soft toric lens |
What are X would be ordered for a rigid gas permeable lenses fit "on K" 43.00 @ 180 / 44.00 @ 90 -3.00 +1.00 x 90 | -2.00 |
To aid in positioning of a rigid prism Ballast Lens riding to low and slipping underneath the lower lid, what might be helpful | Truncation |
The following rigid gas permeable diagnostic lens is placed on a patient I 43.50 -2.00 9.2 In over-refraction is performed with the following result Plano +1.50 x 95 what lens parameters would you order for the patient | 43.50 -0.50 -1.50 x 5 9.2 |
The following soft lenses placed on a patient I 8.8 -4.00 14.0 and over re-fraction is performed resulting in -0.75D sphere what lens parameter would you order for the patient | 8.8 -4.75 14.0 |
In an RGP lens A poorly finished transitional zone between the optic zone in the lens edge can be evaluated by.... | Profile analyzer |
During the diagnostic a valuation of the following patient the lens rotates 10° to the right which of the following lens parameters would you order for the patient Refraction -2.50 -1.00 x 170 Lens. 8.7 -2.50. -1.00 x 170 | 8.7 -2.50 -1.00 x 160 |
What lens designs would not provide a good visual result for this patient 42.50 @ 180 / 44.00. @ 90 -2.50 +1.50 x 90 | Soft spherical lens |
What is an excellent material for a patient with keratoconus | Fluoro silicone acrylic |
A prism ballast RGP Lens requires how much prism for proper orientation | 0.75 to 1.50 D |
What could be considered in the fitting of a Keratoconus patient | Aspheric, McGuire, Soper They are all different types of lenses |
The following soft lens is placed on a patient I 8.4 -2.00 14.2 And over refraction is performed with the following results -1.00 -0.50 x 174 What parameters would you order for the patient | 8.4 -3.25 14.2 |
Given the following information K's 45.00 @ 180/ 44.00 @ 90 Rx -3.00 +1.00 x 180 upper lid positioned at the superior limbus what lens specification would best simulate an intrapalpebral rigid lens fit | 44.50 -2.50 8.5 |
Given the following information which of the lens specification would best simulate a lid attachment rigid lens fitting 42.00@180/43.00@90 -2.00 -0.87 x 180 upper lid positioned 2 MM below the superior limbus | 41.50 -1.50 9.5 |
What bifocal designs represents a translating design | Crescent design |
Giving the following information which of the listed rigid lens designs would you order to best correct the wearers vision 42.00@180/45.00@90 -3.00 -2.25 x 180 | 42.00/45.00 -3.00 -2.25. (Rx form) |
The performance of a soft toric lens depends on | Corneal topography, Lid shape, lid positioning and lid tightness |
Given the following information which of the following RGP lens designs would you order to best correct the patient's vision 45.00@180/42.00@90 -2.00 -4.25 x 90 | 42.00/45.00 -2.00/-5.75 (drum reading) |
Given the following information which of the following RGP lens designs will best correct the wearers vision 42.50@180/42.50@90 -3.00 -1.00 x 90 | Anterior toric design |
Given the following refraction and K readings, select the correct base curve and power recordings (drum readings) 44.00@180/41.00@90 -1.00 -3.00 x 90 | 41.00/44.00 -1.00 -3.00 |
what is not necessary to consider when fitting RGP aphakic contact lenses | Hyperflange design |
A bifocal lens in which the power gradually changes from the central area of the lens to the periphery is known as | An aspheric lens |
An aphakic patient with K readings of 40.50@180/41.25@90, large palpebral fissures and flaccid lower Lids is a good candidate for | A single cut lens |
A patient has a horizontal visible iris diameter (HVID) 12.5 MM the best choice for initial soft lens diameter would be.... | 14.5 |
A single cut aphakic Lens is best suited for patients with _________ apertures and _________ corneas | Small/steep |
Where is the power curve on a Spin-cast soft lens | The back surface |
Keratoconus and penetrating keratoplasty fittings are best accomplished by which of the following methods | Diagnostic fitting |
The following ametropia frequently results in high riding rigid lens | High myopia |
A good example of a bifocal contact lens that may rotate without vision impairment is | Aspheric |
A toric soft lens will correct..... | Residual astigmatism, low astigmatism (0.75-2.00), and moderate astigmatism (greater the 2.00 D) |
A lens fitted for Keratoconus should | Align the apex |
The best option for patients with giant papillary conjunctivitis (GPC) or those who are cooks or hairdressers is | Disposable lenses for daily wear only |
Which of the following is a translating bifocal lens design | Segmented |
Prism ballast, double slab off, and peri-ballast are what type of lens designs | Soft toric lenses |
What is the general rule of thumb when choosing a diameter of a soft lens | 2.0 mm larger than the HVID |
Therapeutic soft lenses should be fit with minimal movement in which case | Recurrent erosion |
42.00@170/43.00@80 -3.00 -1.00 x 170 Given the above RX the following diagnostic toric lens was used -3.00 -1.00 x 180 During the diagnostic evaluation the above lens rotates 10° clockwise the lens ordered should have an axis of | 180° |
Fluoro-silicone acrylic material have __________ qualities that enable patient to blink protein and other deposits off the qualities that enable patient to blink protein and other deposits off the land surface | Non-stick |
42.00@180/42.00@90 -3.00 -2.00 x 180 What is the best lens type for this patient | A front surface toric RGP lens will probably be necessary to correct this patient's residual astigmatism |
A patient's K readings are 43.50@180/41.50@90 What can you expect from a spherical RGP lens | Displace down and in or down and out with each blink |
Which special RGP lens design would be beneficial for this patient given the following information 44.00@180/46.50@90 -11.00 +2.50 x 90 | Hyperflange reduces the edge thickness of a high minus lens increasing patient comfort inn allowing the lens just center better |
During the diagnostic evaluation of the following patient the lens rotates 10° to the left which of the following Lens parameters would you order for the patient -3.00 -1.25 x 160 (pt refraction) 8.4 -3.00 -1.25 x 180 14.5 | -3.00 -1.25 x 170 14.5 |
A patient is diagnostically fit with a rigid gas permeable lenses with the following parameters 42.50 -3.00 9.5. If you wish to flatten the lens to cornea relationship what lens would you order | 42.50 -3.00 9.0 |
Contact lenses are most often specified in | Back vertex power |
The tolerance for the overall lens diameter according to the ANSI standard is | +\- 0.05 |
Name an instrument that will not enable the practitioner to verify the overall rigid gas permeable lens diameter | Radiuscope |
Placing the concave side of a rigid gas permeable lenses against the lens stop of the lensometer will provide you with what | Back vertex power |
An instrument that allows simultaneous verification of lens diameter, optic zone width and Peripheral curve width is | Measuring magnifier |
Assessment of the quality of the Peripheral curves (blends) of a rigid contact lens is achieved by the use of | Profile analyzer |
The instrument used for magnification of the edge of a rigid contact lens is | Shadowgraph |
The tolerance for lens power under +\- 10.00D is | 0.12 |
A warped lens will show _______ base curve(s) on the radiuscope and a __________ power on the lensometer | 2 base curves and a spherical lens |
What instrument does not measure contact lens parameters | Burton lamp |
Prolonged periods of reading in contact lenses may lead to lens discomfort why | Decreased blinking |
How often should new soft lens fits be seen | After one week again after one month three months and six months from the time of their initial fit then every 6 to 12 months |
What material would least likely require a weekly enzymatic cleaner | Polymethylmethacrylate PMMA |
What type of lens would best satisfy this patient's visual needs given the following information 43.00@180/44.00@75 3+ distortion -2.00 +1.00 x 75 | Spherical RGP lens due to the 3+ distortion probably because of irregular astigmatism |
A rigid contact lens measures +15.00 BVP, the FVP will measure | A lesser dioptric reading. The power of a high plus lens will always measure a larger numerical value in the back vertex power (BVP) when compared to the reading in the front vertex power (FVP) |
Which of the following preservatives have a low incidence of ocular sensitivity with Soft contact lens | Sorbic acid |
Patients who are fit with lenses that will be worn overnight on a flexible or extended wear basis should | Should be seen as early as possible in the morning for follow-up of overnight wear |
The base curve of a rigid lens was ordered 7.84 mm and was received measuring 7.94 mm this lens is ___________ than ordered | 0.50 D flatter |
One my utilize which of the following lens designs given the following information 46.00@75/48.50@165 2+distortion -7.00 -3.50 x 165 | Soper Keratoconus design |
Select the power if the lenses ordered 1/2 D steeper than the K 42.50@180/44.50@90 -3.50 -2.50 x 90 | -4.00 D |
The FDA has recommended the extended wear contact lenses should be worn for a maximum of | 7 days |
What preservatives is a mercury based compound | Thimerosal, an organic Mercurial compound |
Carol's contact lenses are fit on black K. Her reflection is -5.00 +2.00 x 90 what's the power of her contact lenses | -3.00 |
When verifying a rigid lens on a radiuscope you notice that the mires are not in focus in all principal meridians, what does this indicate | Warped lens, back toric lens, bi-toric lens |
What may cause a soft lens to need to be replaced more often | Heat disinfection |
Name a preservative found in soft contact lens solutions | Polyquad |
What hobbies and activities should be discussed with patients | Long periods of computer work, long periods of reading, and long periods of driving |
Conventional daily wear soft contact lens this properly care for should be replaced at least | Yearly, this is different than disposable or frequent replacement counterparts |
What are nonapproved wedding solution | Saliva, toothpaste, dish soap. You should only use approved wedding solution for contacts |
Which medications should not be used with soft contact lens is as it will turn the lenses brown | Epinephrine |
What should a patient do if they contact lens becomes adherent to the cornea | Irrigate the eye with saline or rewetting drops until the lens begins to move freely again |
Poor RGP insertion or recentering techniques may result in what | Arcuate staining |
When can Johnny a 12-year-old new soft lens wear comfortably be sent home with new lenses | When he can insert and remove the lens is by himself |
What is the purpose of a combination wedding/soaking RGP solution | Maintain lens surface wettability, Cushion the lens during insertion, disinfect the lens |
Enzymatic cleaning of soft lenses is important because.... | Preventing the development of GPC, maintaining hydration of the lens, preventing the lens from shrinking and tightening |
And how often should eyeliner and mascara be replaced | Every 3 to 6 months to avoid contamination |
What is not considered a normal adaptive response to soft lenses | Lens feeling hot in the late afternoon |
Thermal disinfection of soft lens | Is effective against acanthamoeba cysts, and trophozoites |
What should you do with your solution container after use | Always make sure it is captain to prevent contamination |
Hydrogen peroxide Care systems | Is more affective against viruses and fungi agianst most chemical disinfection systems |
What cannot be used to measure the diameter of a rigid lens | Profile analyzer |
Use of a wretten #12 or ridden yellow filter is important in evaluating fluorescein pattern of patients with RGP lens because | Many patients are wearing lenses containing UV inhibitors that block fluorescein |
If fluorescein evaluation reveals apical staining it could be due to | A lens that is to flatten loose, a lens that is too steep and tight, or corneal edema |
Newly fitted extended where patients should have their first recheck when | 24 hours |
If an adapted contact lens wear complains of a sudden onset of discomfort the technician should suspect | A damaged contact lens |
If an RGP lens fails to provide acceptable visual acuity the fitter should do what first | Have a sphero-cylindrical over refraction performed to see if the reduced acuity is due to residual astigmatism |
According to the FDA disposable contact lenses that are removed nightly should be discarded after | 2 weeks |
Three and 9 o'clock staining in RGP lens wearers can best be eliminated by | Reduce center and edge thickness and teaching the patient to blink completely |
Circumcorneal injection in a soft lens wearers may be a sign of | Tight lens syndrome Solution sensitivity Keratitis |
A technician can perform a preliminary evaluation of a soft contact lens movement by.... | Observing the movement of the lens edge in relation to the position of the conjunctival vessel, having the patient look up and blink, observing movement and lens lag in upward and lateral gaze with a penlight |
What is not true about contact lens movement | A loose lens will be more comfortable than a tight lines |
What RGP Modification cannot be made in the office | Changing the base curve |
What is not a benefit of polishing the lens in the office | Thinner lens edge |
What is the most important feature of an in-office modification unit | Variable speed motor |
If a patient with exophthalmic eyes due to thyroid disease requires a toric lens.... | It may dehydrate excessively due to the lid retraction and dry eye condition that often accompanies thyroid disease, stability will be difficult to maintain since there are no lid forces to keep the lens in position |
What is not a characteristic of corneal Edema | Peripheral flare |
What tools do you use when blending peripheral curves in the office | Radius tools, polishing compound, suction cups or a spinner two |
A slit lamp illumination that gives overall view of the cornea but limits detail is | Diffuse slit lamp |
When keratometric mires reflected off a soft contact lens are only clear when the where blinks the lens fit is to | Steep |
Gross corneal Edema which manifests itself clinically as Central corneal haze is verified by the slitlamp using sclerotic illumination, what specific technique does the examiner use to see this condition | The naked eye and an angle between the slitlamp beam in the eye of 90° |
When inspecting the blend on the bevel of a RGP lens | And I deal blend should show a J shaped or ski pattern in a smooth curve |
Diffuse central punctate staining is an indication of | Tight lens |
Sandy returns to your office after being fit with soft contact lens. She has complaints that the lenses become uncomfortable and burning as the day progresses what might be the reason | The lens is too tight |
With a rigid contact lens in place a fluorescein pattern shows a concentration of Fluorescein inferiorly and superiorly beneath the lens. Which of the following types of astigmatism is represented by this pattern | With the rule astigmatism |
Mary is wearing a rigid gas permeable lenses with a base curve of 43.50 D And a power of +2.75. She requires a -0.75 sphere over this Lens if you wish to order her a new lens with a base curve 43.00 what would the new power be | +2.50 |
FDA group I soft lenses | Low-water content less than 50% and a non-ionic service |
What type of slit lamp illumination will allow you to determine corneal thickening, thinning and distortion and depth of foreign bodies or opacites in the cornea | Optic section |
A soft lens has edge lift when observed on the cornea how can this be corrected | Steepen The base curve |
Corneal Edema is observed inferiorly under a prism ballast toric lens what is the probable cause | Prism thickness is too great |
In evaluating a soft lens with either ketatometry mires or retinoscopic reflex, you detect distortion immediately after the blank followed by clear mires, this is caused by what | A flat fitting lens |
FDA group IV lens is? | Negative charged surface that attracts positively charged tear film, proteins and lipids |
Which type of slitlamp illumination is used for observing tear break up time | Diffuse illumination |
A non-wedding rigid gas permeable lenses may cause | Hazy filmy vision Dryness or grittiness Lens awareness |
What are the causes of lens flexure | Pressure exerted by the upper lid High DK lens material Apical clearance lens design Against the rule corneal toricity |
When evaluating fluorescein patterns, a special filter must be used with | Polymers with a UV blocker |
A normal fitting standard thickness soft contact lens will exhibit what | 3 point touch |
What could cause a patient's rigid contact lens to displace frequently and pop out without cause | Excessive posterior Peripheral curve Flat base curve relationship |
Which is the latest lens design for Keratoconus | Rose K design |
A soft contact lens that is too loose will not show | Limbal compressions |
A patient with a high degree of with the rule astigmatism fitted with a spherical rigid gas permeable lenses will show touch | On the horizontal Meridian |
A rigid lens showing excessive apical pooling is an indication of | A steep fit |
A rigid lines showing apical touch is an indication of what | A flat fit |
Contact lenses that have non-spherical back surface are called | Aspheric lenses |
A rigid lens showing central building is an indication of | Apical clearance fit |
A rigid lens showing a band shaped area of touch on the flattest meridian is an indication of | An astigmatic fit |
When there is a slight pooling of fluorescein in the Peripheral curve portion of a rigid lens that indicates what | Slight edge lift |
Rx -3.00 -1.00 x 170 8.8 -3.00 -1.00 x 180 Once the correct Lee ordered lens has been dispensed the rotation marks should settle at? | 10 degree clockwise |
On a compromised cornea, such as one that has undergone a corneal graft what lens characteristic would be most beneficial | High DK/L |
What 2 lens design changes might be helpful in centering a high riding myopic lens | Hyperflange lenticular Prism ballast |
rigid gas permeable lenses flexure may be eliminated by | Reducing sagittal vaulting Increasing center thickness Choosing a lower DK material |
A low riding high plus Lens on a 40.00@180\40.75@90 cornea should be corrected with | A myoflange lenticular |
Mike, a welder who's RX is -6.00+2.00 x 180 has been advised to trade his PMMA lenses of 20 years for a modality that allows more oxygen to the cornea what is the first choice | Low to mid DK RGP |
A technique for correcting a high riding rigid minus lens maybe to use... | Prism ballasted lens |
Advantages of a myoflange versus a single cut high plus Lens include | Reduce center thickness Increase optical zone Reduce weight |
To increase tear exchange with a rigid gas permeable lenses what should not be used | Increase the Sagittal depth |
What polishing compounds should not be used with gas permeable lenses | Silvo |
In order to create a smooth blend between the intermediate and Peripheral curve of the following contact which radius tool should be used CPC 7.50 mm (45.00 D) IPC 8.50 mm PPC 10.50 | 9.5 mm |
To correct a flat fitting rigid gas permeable lenses you should | Enlarge the optical zone |
After building up her wearing time, Jennifer returns for an afternoon recheck after eight hours of lines where the lens moved <0.5 mm and her complaints were minimal except for late afternoon burning what would you suspect | Tight lens |
Which of the following will not increase the movement of a tight fitted rigid gas permeable lenses | Enlarge the posterior exam |
Which of the following is not important to document in the medical records for a contact lens patient | Location at which the patient was originally thought insertion and removal |