Lecture 1 Soft CL WorkUp slide 41 PDF

1 2 -why would we want to use soft lenses knowing that the pt can get inflammation, infections -pt wears CL for cosmetic purposes -the benefit of CL, gives you wider VF compared to spectacles -risk of wearing cosmetic CL is significant and are limited -therapeutic CL where pt achieve better acui...

1 2 -why would we want to use soft lenses knowing that the pt can get inflammation, infections -pt wears CL for cosmetic purposes -the benefit of CL, gives you wider VF compared to spectacles -risk of wearing cosmetic CL is significant and are limited -therapeutic CL where pt achieve better acuity from CL than they do from spectacles and especially pts with severe dry eye, trauma, surgery 3 -assessment of ocular tissue can help determine if pt is good CL candidate -pt with severe dry eye wouldn’t be a candidate for CL bc the risk outweighs the benefits 4 -abusing CL, wearing for too long, not replacing lenses puts ocular surface at risk and its impt to minimize these risk factors by teaching pt appropriate CL care system 5 -there are complications with refractive surgery, pt can get recurrent corneal erosions post surgery so not everyone is a candidate for lasik 6 -vaccines is another ex where pt is exposed to potentially infectious inflammatory substance 7 8 9 -dailies wear: pt puts CL on in the morning and wears it all day and takes it off at night to be not worn the next day -flexible wear: pt can sleep in CL for 2-3 nights and then take it off 3rd day -extended wear: pt wears CL and wears it for 6 nights and takes it off on 7th day -continuous wear: pt wears CL for 30 days and takes it off the day after -dailies: worn once a day and the reuse of that lens has adverse risks so the healthiest one to wear is daily bc it’s not being reused so you’re not exposed to the same debris from previous day -2 week: pt opens lens on first day and wears the lens and the 15th of the month, pt has to discard and use a fresh pair of CL -the wear and replacement schedule is the same for the CL that are listed -advocate for replacing CL case every 3 months bc it’s contaminated from the outside and is not being disinfected properly which can spread to CL 10 -soft CL can induce corneal swelling -if any pt sleeps at night, there is a reduction in oxygen being delivered to the eye but the pt won’t know the cornea is swollen bc there is no adverse effect despite having 3.2% of edema but the cornea is able to tolerate that much swelling when sleeping -adding CL to wearing throughout the day doesn’t increase the lack of oxygen however if pt sleeps with CL at night, they will increase the amount of lack of oxygen and will get more swelling as well as red eyes 11 12 -therapeutic wear à pt cornea is abnormal and need CL -abnormal cornea makes it difficult for pt to see and decreases their VA 13 -high spectacle rx results in high level of magnification or minification so fitting them with CL that effect goes away and see objects at the natural size -ex if pt is -8 in one eye and +4 in another eye, they can’t wear spectacles bc the image will be distorted so CL would be beneficial for them since it won’t change retinal image and give them a distorted view 14 15 -CL are FDA approved class 2 product 16 17 18 19 -hydrogel was the first CL material that was used -material we use now is silicone hydrogel CL à more oxygen permeability than hydrogel -silicone is more rubbery and using it for high plus rx pt bc thickness affects oxygen permeability -base curve is the inside curve and should have some relationship to the curvature of the pts cornea -anything between +10 and -10 is considered special CL and need to be fitted into diff CL 20 -no CL should be exposed to tap water or lake water any kind of water bc it can introduce germs to the eye so pt should clean lenses with solution -pt who swim are recommended to use ortho K lenses so they can swim without correction to avoid contamination 21 -end of day dryness 22 -people drop out of CL due to dryness they experience at the end of the day from wearing CL -when fitting the pt you want to look at their lids, MG, TBUT, to see how healthy the tissues are and see how wet or dry the eye is -pt might be recommended to wear dailies to reduce the end of the day dryness and blurriness they experience 23 24 25 -2 diff pts shown above -HVID is measured using a ruler and in mm -pupil diameter is impt especially in dim light bc if the CL is smaller than the pupil, pt will complain of blur at night -greater than 13 seconds is considered wet eye and less than 9 seconds is considered dry eye -for 31 year old pt, at corneal plane, the rx will reduced when pt is fitting in CL according to Tyler’s book so pt in CL would be either -15.50 or -15.75 -avg vertex distance is assumed to be 11-12 mm -anything greater than 45.00 K for corneal curvature is considered a steep cornea that means that the base curve has to be steeper than the avg base curve found in soft CL so pt will need specialty CL 26 27 28 -pt with these conditions are not candidates for cosmetic CL due to extreme dry eye 29 -L for lupus and L for lacrimal gland destruction -thyroid is the only one that has incomplete blink everything else is lacrimal gland destruction 30 -pregnancy leads to increase corneal sensitivity and CL they wore prior to pregnancy will be uncomfortable and pt will also have decrease in lacrimation -type1 and 2 have decreased corneal sensitivity and are prone to more infections and rate of healing is slow -diabetes doesn’t mean the pt isn’t a candidate for CL but will have more complications when wearing CL 31 -hyperthyroid or grave’s disease causes incomplete closure of the lids which can cause dryness in the eye -MGD they will be missing the lipid layer of their tear film to prevent abrasion and as a result they will have a short TBUT and more abrasion -lost MG they will have drier eyes than normal and challenge their ability to wear CL -lagophthalmos: incomplete closure leads to lens dehydration 32 -taking anti-histamines is to dry out mucus production so they are less congested but also means you have dry eyes when wearing CL -taking antidepressants decreases aqueous production as well -acne meds are on meds for a period of time so wearing CL after the complete the course is preferrable 33 -BP meds can cause end of the day dryness 34 35 -epithelial cells are abnormal in recurrent epithelial basement layer disruption and can get worse overtime -pt with corneal trauma and laceration there is scarring so better for therapeutic than cosmetic 36 -pt are wearing therapeutic to protect the corneal surface -have haziness to anterior chamber 37 38 -also called MAP dot dystrophy -epithelial tissue have microvilli but if epithelial tissues are abnormal they lack microvilli, there is no where for mucin to adhere so when you put fluoresceine, these areas show up as nonwetting leading to a dot appearance -pt have dryness without CL and the symptoms worsen with cosmetic CL -these pts can be fitted with therapeutic lens that bridge over the epithelium to keep the epithelium in a sterile state 39 -scar tissue that origins at the bulbar conj and goes over the limbus and iris -cosmetic lens wouldn’t be able to lie down on the eye bc pterygium is elevated -after surgery, pt still wouldn’t be able to wear cosmetic lenses and would be fitted in therapeutic instead 40 -prescribe pt with bandage CL aka therapeutic -aggressive neovascularization due to viral infection or abuse in CL wear, you don’t want to fit them in cosmetic bc it will continue the neovascularization since the cornea won’t be getting oxygen and will also obstruct the pupil 41