Usually over 40 years of age Unable to accommodate. Near VA continues to decline until age 60. These patient’s may have refractive error in addition the presbyopia.
There are a lot of options. Make sure that you go over all of the options with the patient. Ask the patient what they hope to achieve. CL’s for distance with readers over the top. Bifocal CL’s Monovision
Bifocal contact lenses Bifocal contacts correct for distance, intermediate and near vision. Distance VA is in the center of the CL and concentric rings on the outer portion of the CL are for intermediate and near VA. While focusing at a distance the pupil is smaller, using the center portion of the CL. While focusing closer, the pupil gets larger, utilizing the outer portion of the CL. Bifocal CL’s take several tries to get the best VA. Distance VA may be fine for the patient but the near VA may not be clear enough and have to be changed, which will effect the dist VA. Thus, several tries to get the best VA in ALL focal lengths. Make sure the patient know that their VA will not be perfect at all focal lengths. There will be a sacrifice of clarity for the convenience.
Bifocal contact lenses Take your favorite teacher! 44 year old Wants CL’s for dist and near. Has dist CL’s and readers now. Not happy with it! M Rx= OD sph OS sph Add OU Best corrected VA OD 20/40 OS 20/20
Bifocal contact lenses Trial lens Acuvue bifocal Only has adds of +1.00,+1.50,+2.00 &+2.50 Trial lens OD-3.50 add OS-3.00 add VA OD 20/40 VA OS 20/30 Near VA OD 20/40 Near VA OS 20/30 Normal VA is 20/40 &20/20 try a new lens! Acuvue bifocal trial OD OS VA OD 20/50, 20/40 VA OS 20/25, 20/25 Patient is not happy with this either! Pain in the On to the next lens.
Bifocal contact lenses Let’s try a Cvue bifocal trial lens. OD-3.00 low add OS-3.25 low add VA OD 20/40, 20/40 VA OS 20/20, 20/25 Patient is happy, not perfect but happy. Remember, every time you mess with the dist power, it will effect the near power and visa versa. For example……. add If you change the add to +2.25, that’s like adding +.25 to the distance Rx and the patient may not see as well dist, but may see better at near. To counteract this change dist to-2.75 and add at +2.25
The same will happen for near vision bifocal CL changes. Trial lens OD +4.00, add VA 20/30,20/20 OS +3.50, add VA 20/30, 20/20 Dist VA not working, change trial lens to…… OD +4.50, add VA 20/20, 20/30 OS +4.00, add VA 20/20, 20/30 now, dist VA is great but near is horrible. What happened? YOU TELL ME!!!
Bifocal contact lenses By increasing the dist Rx we made the dist VA better but it also effected the reading VA by adding to the near RX. What should we have anticipated and done before putting those trial lenses on the patient’s eyes?
Whatever you add to one focal length, take away from the other! We added to the dist Rx, which in turn also inadvertently add to the add also. Destroying their 20/20 near VA. Add to the near vision Rx to counteract the we added to the dist Rx. Anticipate what will happen if you make a change in the power and you will go through a lot less trial lenses.
monovisionmonovsion Monovision is distance correction in one eye(dominant eye) and near correction in the opposite eye (non- dominant). Patients trying monovision need to be motivated and it will take a couple of weeks to get used to. People either love or hate monovision, those who love it get used to it fast. Never leave a patient with a pair of trial lenses they don’t feel comfortable with if they need to drive. Just like bifocal CL’s, monovision will sacrifice overall VA for the convenience. You will need to establish the dominant eye before anything.
monovisionDetermining dominant eye There are many method of determining eye dominance. Page 133 has 5 ways. Usually dominant eye is the same as your writing hand, but not always! Here is one we can all try! Hold a pen at arm’s length. Using the tip of the pen as the sight, line the tip up with a fixation light while both eyes are open. DO NOT move your head or hand while you occlude one eye, then the other. One eye will keep the light and tip of the pen very close while the other eye will displace the tip of the pen and the light. The displaced eye is the non- dominant eye.
monovision Rx OD -3.50,+2.00add OS -3.25,+2.00add OD is dominant Add the patient’s add to the non-dominant eye. dist add Rx for OS Rx for OD This patient will use the right eye for distance and the left eye will be used for reading. The patient will not have to concentrate any more than normal. Their brain will just do it. They will either love it or hate it.
monovision Dominant eye is ALWAYS the distance corrected eye. Add the add power to the patient’s non- dominant distance Rx. That will become the “reading” eye. Remember….. There is a sacrifice of overall visual acuity with monovision. This is not a good suggestion for someone who drives all day or someone with a job that requires close reading or computer work all day.
Bandage lensesReasons for a bandage lens Contact lenses are used as a therapeutic to aid in healing or preventing pain from some sort of pathology. They are referred to as “bandage lenses”. There is no power in the lens. It is used as a bandage to promote healing. Corneal ulcer Corneal errosion or recurrant corneal erosion. Corneal abrasion Chemical burns Basement membrane dystropies S/P incision corneal Sx
Bandage lens help pain with bullous keratopathy patient Bandage lens help to keep epithelial cells in place to heal a leaking bleb
Bandage lens on a huge corneal abrasion Bandage lens over a penatrating keratoplasty
BANDAGE LENS OVER CORNEAL ABRASION ANOTHER BANDAGE LENS OVER A CORNEAL ABRASION
COLORED CONTACT LENSES MORE COLORED CONTACT LENSES
Used in patients with out an intra ocular lens to replace the power of the crystalline lens. Can either be pediatric or adult caused by congenital, traumatic or removal of cataract with no intra ocular lens implanted. Either hydrogel (soft) or gas permeable can be used. Soft are preferred on pediatric patients. Aphakic lenses are usually very high plus. to depending on the refractive error before the cataract. BC and D are determined normally. Pediatric patients will have 12.5 to 13mm D. smaller than normal adult diameters.
Soft lenses are limited to very early keratoconus. They are not able to exert enough pressure on the cornea to change the shape and/or retard progression. Soft lenses are only used in a “piggyback system” in conjunction with a rigid lens. Gas permeable lenses are primarily used for keratoconus patients. Three types of fitting styles are used, apical bearing, apical clearance, three point touch. All of these have their flaws and constantly need to be changed because this is a progressive disease.
Keratoconus can very hard to fit properly. Because of the cone shape and thinning cornea, you must be very experienced in CL fitting.
Next week is MIDTERM! Study! for any help you may