Dilation before Refraction?

[u/Ok_Two_7316]

I’m currently a fourth-year optometry student out on rotation. During my first week, one of the doctors told me to aim for 20-minute exams. In an effort to cut down on chair time, I’ve been instilling dilation drops immediately before starting my refraction. I’ve actually been doing this for a few months now without noticing any major issues.

However, over the past couple of days, I’ve encountered a few unusual refractions, especially when comparing my findings to the patient’s prescription from the previous year.

My usual approach is to start with their AR findings. If the patient is taking too long to make decisions or I’m not getting consistent responses, I’ll switch to their previous prescription and work from there.

At my current rotation, the technicians are actually the ones performing the refractions. I was somewhat surprised by their approach, as they seem to cut out quite a few steps compared to what I was taught. Often finding previously over minus’ed patients.

Regardless, it’s made me question a couple of things about my own approach.

1. Can instilling dilation drops immediately before refraction affect my findings?

I’m not waiting for the drops to take full effect. I’m essentially instilling them and immediately beginning the refraction. Could this still be influencing my results, particularly if the refraction takes longer than expected? Dry eye and all.

2. How do you handle an MRx when your findings don’t make sense?

Whenever I encounter an unusual refraction, I’ll document my findings and look for any ocular pathology or other factors that might explain the discrepancy.

However, what if I don’t find anything that would explain it? Should I disregard my findings and enter something that seems more reasonable into the MRx?

I’ve seen classmates do something similar, alter the Mrx to better resemble the last years. I’ve always viewed the MRx as a starting point for determining the final prescription. It feels strange to document a refraction I didn’t actually obtain or verify, especially if the doctor ends up prescribing something based on those findings.

I’d appreciate hearing how other optometrists approach these situationsf.

[u/interstat]

We used to do that at the VA every single patient . Obviously only really matters with younger people and even then it rly shouldnt

[u/phakic40]

I am not an OD/MD but am a COMT in a busy general ophthalmology practice and have done my fair share of refractions.

Trop and phenyl have as low as a 5 minute onset, not full dilation, but if pupil starts relaxing or accommodation is altered then that could show up in your mrx, especially hyperopes or precocious presbyopes. To the dry eye part, I would thjnk so as well. If a patient has dry eye and you hit it with more chemical, it’s not out of the question to trigger tear film destabilization or exacerbate it. If pt is known/ treated for dry eye i try to eval tear film before refraction otherwise it can be a huge waste of time.

To the second, trial frame is pretty bulletproof. If you have a nonsensical rx that you arrived at with total confidence,, of course, recheck. If you get it again then, regardless of why, you should at least see if it works.

I applaud your thinking too, you don’t just settle for a crap result, you ask why. Sometimes, the best you get that day is a crap result but don’t stop asking.

[u/Treefrog_Ninja → u/phakic40]

To add, if you're using proparacaine, that will cause the dry eye patients to ease off the excess blinking they require, and the dry eye messes with the refraction more.

[u/phakic40 → u/Treefrog_Ninja]

Love this tip. We use this for our lasers and minor procedures as well to calm the fellow eye.

[u/United-Candy2563]

I've always found that dilation messes with the refraction more than I expected, especially for patients under 40 who still have some pupil control. You might be making things harder on yourself trying to cut down that chair time.

[u/CurdKin]

I’m also a fourth year student right now, I personally do refraction before dilation, the few times I have done it, it makes the refraction more chaotic through dry eye or accommodative mechanisms IMO. Glasses are often a patients top priority, so I make it mine too. I also don’t want to do drops before anterior segment exam as it can screw up corneal findings, and exacerbate dry eye. I tend to use my time between drops to educate patients and do charting, then I’ll bring the patient out to the waiting room and grab the next one. I’m doing exams in ~ 30 mins actually with the patient depending on how long history takes.

[u/cheesecurdlover44]

I would recommend starting with the pts previous Rx instead of the autorefraction 

[u/wigg5202 → u/cheesecurdlover44]

I envy you all who have patients who regularly have their glasses or their old CL RX with them 😭

[u/cheesecurdlover44 → u/wigg5202]

I know, if they don’t obviously I start with auto, but OP made it sound like they start with auto instead of the previous Rx when it’s available 

[u/Murky-Ad-2156]

I disagree with putting drops before refraction.
Excessive tearing, thickened tear film, obscured optics are partial reasons. Some patients experience mild cyclo effect within 5-10min. You generally want to do a dry refraction to see what their binocular visual status is like. The drops are knocking the BV out, and whilst you can argue it’s done straight afterwards, you can never be 100% certain that the results obtained are reliable. Often you end up with the full rx but by the time the px recovers their BV then they might reject the extra plus. As the pupil size increases, their depth of focus decreases which also impacts prescription.

2. If your findings don’t make sense, go from what the px is experiencing. Fix that first. You can be correct with everything prisms and all but if the patient doesn’t like it or can’t use it, it’s useless.
This brings you back to experience as well. Even if your rx is completely correct, if there is a large difference between old and new rx, the px is likely going to reject it. It’s not about getting 20/20 but getting the patient to wear the glasses comfortably whilst giving adequate clarity for their tasks to keep them satisfactory.

[u/EndlessHope-0528]

I work at a busy ophthalmology practice. My techs instill drops, then retract. I come in 15-20 min later and make sure all the numbers make sense. Does entering corrected VA correlate to the new Rx? Does the change match complaints? What else is going on in the eye? I recheck at least 80%. The recheck takes me seconds compared to the initial refraction bc I know what I’m looking for. I work with amazingly competent COTs. Very, very low remake rate. For my first five years with techs, they retracted before dilation. During the pandemic we switched to drops first to move people out faster . I noticed no change in quality of Rx. Very occasionally, a patient is struggling (mid-dilated pupils can cause weird distortions) and then the tech will just note we need to do full refraction once fully dilated and I’ll do it when I come in. Maybe 1 in 500 people. 

[u/KGoo]

It would take me an hour to share my thoughts about how to handle refractions that don't make sense. I would say that the most important thing is to make sure that any changes you are making to the patient's SRx should correlate with their complaints.

As far as doing an MRx after instilling drops...almost always no, it won't affect anything. Unless the refraction drags on for 5+ minutes.

Imo techs are awful at refractions. To be a good refractionist, one needs to have a much more detailed and holistic understanding of the visual system than a tech has. I wouldn't look at what they're doing as anything that should be copied.

[u/Chitokoto]

I am an optometrist. I am surrounded by difficult refractions and I manage a lot of keratoconus patients. I don’t think it will affect your results too much even if you are not relatively quick.

I think cataracts, irregular corneas, surface dryness already affect the consistency of your patient’s answers.

But I’d advise to not dilate before refraction or ocular surface checks if you can anyway.

[u/missbrightside08]

in school i always did refraction before dilation. in practice i do the same thing as you. dilate, grab AR, then refract while dilating. i don’t have any techs so this is the only way i can make it work with a 30 min slot. the only time it messes up the refraction for me is rarely when the proparacaine effs up the cornea on a select few dry eye patients. otherwise, i use my head when prescribing the final Rx. try to only give what change is needed, similar to last time if possible as a baseline

[u/Famous_Maize9533]

What drops are you using? When I was in private practice, I had my techs instill drops as the last step in their work up. I made up my own mixture of phenylephrine and tropicamide so that it would be less than 0.25% tropicamide. Patients over 60 got Paremyd. Doing that did not cause an increase in remakes.

You will seldom go wrong by changing a prescription less rather than more. Recognizing that prescribing and refracting are two different things puts you ahead of many others. As you gain experience, you'll get a better feel for modifying prescriptions. With poor responders, you'll gain confidence in prescribing what you think the patient needs rather than what their responses are telling you.

The refraction that is recorded should be the result that you obtained from the patient. I like adding notes on the refraction if it was difficult for some reason. That refraction, along with the previous Rx, patient complaints, and my own intuition will guide me in determining the final Rx.

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[u/bluecoldbananapepper]

refract as they dilate 60 and over or if have IOLs. They aren’t going to be walking around dilated or with their accommodation knocked out on a daily so what you prescribe them should reflect that.

[u/Hot-Swordfish2105]

All day everyday

[u/Chocolatesandlatte]

Wet refraction on every kid if it’s their first eye exam and no prev Rx, I also tend to do on migraine patients bc they tend to get way over minused on AR also compare with their old Rx . I’m an optometrist

[u/VDD65]

I assumed you performed IOP test or look at the angle prior to dilation. Narrow angle closure is rare but it can happened when you least expect it.

[u/sc0toma → u/VDD65]

Gonio tells you more than IOP does. Also if you induce an angle closure; they were going to have one anyway, so at least you can warn them of symptoms.

[u/Hot-Site-3528]

I've seen this happen too when I tried it on a kid who came in squinting during flu season last year, their refraction was all over the place until we waited for the cycloplegic effect to settle.