Baseline Visual Acuity

[ituryu]

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What is/are your gold standard acuity(s) that you would refract your patients, let's put it this way, based on symptoms, your preliminary examfindings such as your A of A, NPC, and retinoscopy.
Would you make sure a 20/15 VA be attained especially if we look at presbyopes and patients using IOLS.
Dare to contribute wisely!!! 😀

 

[Opii]

What is/are your gold standard acuity(s) that you would refract your patients, let's put it this way, based on symptoms, your preliminary examfindings such as your A of A, NPC, and retinoscopy.
Would you make sure a 20/15 VA be attained especially if we look at presbyopes and patients using IOLS.
Dare to contribute wisely!!! 😀

Are you in the Nigerian Optometry school? I've seen notes from your program. It's very complete and I'm sure you have the same information we have.
Gold standard VAs = Goal RX is always 20/20 monocular first. then binocularly. Most people like MPMVA. Most plus for maximum visual acuity.... to avoid over minusing them.
AOA depends on their Age ... look for Donder's Table. (I know you have that information in your notes).
NPC ... 10/7/8 cm approximatly
If you get 20/15 great, no objections there, don't see why there should be concern with presbyopes or IOL patients, accomodation wouldn't be a concern obviously.
I hope I didn't just complete your homework.

 

[ituryu]

Are you in the Nigerian Optometry school? I've seen notes from your program. It's very complete and I'm sure you have the same information we have.
Gold standard VAs = Goal RX is always 20/20 monocular first. then binocularly. Most people like MPMVA. Most plus for maximum visual acuity.... to avoid over minusing them.
AOA depends on their Age ... look for Donder's Table. (I know you have that information in your notes).
NPC ... 10/7/8 cm approximatly
If you get 20/15 great, no objections there, don't see why there should be concern with presbyopes or IOL patients, accomodation wouldn't be a concern obviously.
I hope I didn't just complete your homework.

Well yes I know this and the answer to your question is yes, but one thing that I was taught is that 20/15 is supranormal visual aquity and it tend to be a state of over correcting or under correcting, especially if the patient complains of headache, and for hyperopes, you tend to get less plus especially if you keep them at 20/15. I do Have Donder's tableand the said Norm for NPC is 6/9 cm break and recovery and I think the 20/15 would still keep the patient(px) in a visual discomfort.
Let's chew and ponder on this.
Thanks and hope to hear from you soon. 😎

 

[Opii]

Well yes I know this and the answer to your question is yes, but one thing that I was taught is that 20/15 is supranormal visual aquity and it tend to be a state of over correcting or under correcting, especially if the patient complains of headache, and for hyperopes, you tend to get less plus especially if you keep them at 20/15. I do Have Donder's tableand the said Norm for NPC is 6/9 cm break and recovery and I think the 20/15 would still keep the patient(px) in a visual discomfort.
Let's chew and ponder on this.
Thanks and hope to hear from you soon. 😎

A safe rule of thumb is sticking to 20/20. You cannot make a person into a 20/10, 20/05 if you keep "correcting" them. Although some patients think so. There are several theories why some people can see better that 20/20... The size of the cones, the processing pathways. That is why Hawks see better than 20/20, their cones are more densely packed & thinner. This information is in Schwartz's visual perception book. MPMVA works most of the time. The more the plus the more you relax their accommodation, but you want them to see 20/20, if it gets blurry again then they are over plused. And remember visual optics. The focus point doesn't fall "on" the retina anymore. This wouldn't change their vision into a 20/15, unless physiologically they were capable of it anyway. If a patient sees 20/15 comfortably I wouldn't blur them back into a 20/20 "just because".

 

[ituryu]

A safe rule of thumb is sticking to 20/20. You cannot make a person into a 20/10, 20/05 if you keep "correcting" them. Although some patients think so. There are several theories why some people can see better that 20/20... The size of the cones, the processing pathways. That is why Hawks see better than 20/20, their cones are more densely packed & thinner. This information is in Schwartz's visual perception book. MPMVA works most of the time. The more the plus the more you relax their accommodation, but you want them to see 20/20, if it gets blurry again then they are over plused. And remember visual optics. The focus point doesn't fall "on" the retina anymore. This wouldn't change their vision into a 20/15, unless physiologically they were capable of it anyway. If a patient sees 20/15 comfortably I wouldn't blur them back into a 20/20 "just because".

I think you sent a private message I can't open it, but it's hard keeping to the rules that supranormal acuity of 20/15 is not acceptable and that if you have the px complaining of headaches, I think that's it, but I also think if a patient comes complaining of poor distance vision, I would guess they are over accommodating for the task distance, and thus becoming myopic if we look at it from a visual optical point of view.
I'll get back to you on this.
Stay well, and thanks for taking time to remove the doubts in me. 👍

 

[ucbsowarrior]

What is/are your gold standard acuity(s) that you would refract your patients, let's put it this way, based on symptoms, your preliminary examfindings such as your A of A, NPC, and retinoscopy.
Would you make sure a 20/15 VA be attained especially if we look at presbyopes and patients using IOLS.
Dare to contribute wisely!!! 😀

depends on the functional needs of the patient. it's all case by case...depending on u'r patient's needs.

 

[Opii]

... but I also think if a patient comes complaining of poor distance vision, I would guess they are over accommodating for the task distance, ...

Distance complaints due to accommodating problems? Hmmm
Can you refer me to one book where 20/15 supranormal acuities are considered bad? Anyway good luck with your projects. Your IOL industry experiences sound interesting. I've heard of these industries; they have them in India too right? Sounds interesting.

 

[cpw]

In my experience most patients (young enough to not have beginning cataracts) are 20/15 OU. 20/20 individually (OD/OS)

 

[ituryu]

depends on the functional needs of the patient. it's all case by case...depending on u'r patient's needs.

Well some patients dodo not know what they really need. For instance look at a patient who can make 20/15 visual acuity status and also an accompanying headache as his chief complaint which he noticed whenever he is doing any near visual activity, and he still wants to see 20/15, which clearly points to an accommodative excess, and thus his VA should be brought to 20/20 with more plus for him to have comfortable binocular vision.

 

[ituryu]

Distance complaints due to accommodating problems? Hmmm
Can you refer me to one book where 20/15 supranormal acuities are considered bad? Anyway good luck with your projects. Your IOL industry experiences sound interesting. I've heard of these industries; they have them in India too right? Sounds interesting.

Some people have poor Distance vision with headache comlain associated with near work.And thank for the good fortune wish I appreciate it. As per book for the supranormal acuity I was thought that by my lecturer and all clinical rounds I have made on this basis have been sound with the patient RTC w/o complain but are better off!!! Hmmm! I keep post alive.

 

[Opii]

... which clearly points to an accommodative excess, and thus his VA should be brought to 20/20 with more plus for him to have comfortable binocular vision.

To clearly point out Accommodative Excess you need to measure with vergences and phorias.

 

[Opii]

Some people have poor Distance vision with headache comlain associated with near work.And thank for the good fortune wish I appreciate it. As per book for the supranormal acuity I was thought that by my lecturer and all clinical rounds I have made on this basis have been sound with the patient RTC w/o complain but are better off!!! Hmmm! I keep post alive.

Can you ask your lecturer where the information came from? One Book or One Website indicating how 20/15 can be a bad thing?

Putting +0.50 diopters on a distance Rx for reading, I have seen that done (in kids). For older people, wouldn't it just be better to give them bifocals? So they can have sharp distance vision and sharp near vision? Especially if they are presbyopes or have IOLs. +0.50 would not even be sufficient. You have to choose your words more carefully. When you say distance vision at 20/15 is due to accommodation problems well, that is two different things, many people see 20/15 distance and don't have trouble reading. It is NOT A SET RULE ... I would love to see one book or one website stating that.

Perhaps I am a "freak of nature" then, I see 20/15 at distance and read all day without complaints

 

[ituryu]

To clearly point out Accommodative Excess you need to measure with vergences and phorias.

Yes I agree and this is becos you would like to determine your AC/A Ratio, but remember that you would stil need to have your NPC value, the patients Aof A to go with the age, as these would serve as both a clinical parameter for dx., and documentation.
Anything else? I think the binocular flipper test would be for detecting lag in accommodation. Hmmm!

 

[Opii]

Yes I agree and this is becos you would like to determine your AC/A Ratio, but remember that you would stil need to have your NPC value, the patients Aof A to go with the age, as these would serve as both a clinical parameter for dx., and documentation.
Anything else? I think the binocular flipper test would be for detecting lag in accommodation. Hmmm!

Yes ... It's all so very interesting. 🙂

 

[ituryu]

Yes ... It's all so very interesting. 🙂

Hmmm! I wonder what are the other criteria?

 

[ucbsowarrior]

Distance complaints due to accommodating problems? Hmmm
Can you refer me to one book where 20/15 supranormal acuities are considered bad? Anyway good luck with your projects. Your IOL industry experiences sound interesting. I've heard of these industries; they have them in India too right? Sounds interesting.

it's bad for the aforemetioned if they are myopic.

also if they have acc. lag, they may benefit from a under minused rx (myopes) as postulated by some studies....may reduce axial growth.

i'm sure there are as many reasons for do's and don't...read up and use your own judgement.

ucbsowarrior

 

[ituryu]

I think you have to find the basis for your proper refraction from follow up visit, if you know what I mean!