I don't like to repeat myself too much, so I won't write much here. I think the video is pretty self explanatory, and you can read more here.
Had a fun conversation with my 4 year old the other day about birds going south for the winter. We talked about how they pack their suitcases with food, clothes, and beach toys. I thought I'd do an illustration..
Oh yeah - he insisted the bird has a mustache - who am I to argue?
A long while back, perhaps in about 2003, I created a tutorial to teach the basics of refracting. I think I spent nearly every night and weekend on it for about a year (that was when I didn't have any kids, and my wife worked a lot of hours that I had off and vice versa).
I actually didn't even know what I was going to do with it when I finished it, if I ever did. I ultimately did finish it, and by a recommendation by my old ICO roomate, I ended up publishing it at medrounds.org. Like anybody who creates things, I'm very critical of my own work, but overall I'm proud of conceiving this and putting in the work to see it through to completion. It has generated some small extra income, although I don't think I want to know what the hourly wages would break down to! To be frank, however, I really don't care - it's been very rewarding to hear the feedback over the years and I hope I've helped a lot of new optometrists, ophthalmologists, and technicians get their feet wet with refracting concepts.
A few days ago a comment appeared on the youtube screencast I recorded to introduce this tutorial.
I was very disappointed. There's only 15 case studies, and then pretty much all you're left with is with the option where you manually input the target refraction... well that's not too useful is it since you already know what the endpoint refraction is gonna be!
It's always difficult to hear criticism of your work, but the more I thought about it, the more I saw this person's point. Of all the time I spent programming, drawing images of phoropters, etc., I should have spent some more time creating case studies. That would have been very easy. Or, I should have provided an option to generate random cases.
To be honest, I'm a little afraid to try to add features to this tutorial at this point. It's been quite a while since I've worked on it, and it's kind of like a swiss watch. If open it up and start tinkering with it I'm afraid I'll start breaking things and I'll never get it put back together again.
The good news is, it's actually quite easy to add patient cases to this tutorial. Somehow I had the foresight to separate the patient cases from the rest of the programming.
To do this, you will need to copy all the files on the CD onto your computer. I'd put them all into a folder (directory) - call it something clever, like "refraction tutorial". Then, within that file, find a file called patient_files.xml.
if you open this file, you'll see an xml document that describes all the patient cases that are included in the refraction tutorial. I won't go into too much detail here, but if you look at the structure I think you'll figure it out and should be able to add more patients.
But wait! Before you start messing with the contents of this file I'd recommend making a duplicate of the original, and rename it to something clever like patient_files_original.xml. Computers can be pretty picky about the syntax of XML. If you make a mistake you might find yourself in a position where you don't have any cases to work with!
However, I really don't like the idea of people having to populate this XML file to generate more virtual patients to refract. So, I spent the last couple nights writing a script to generate some data for you. The script uses totally random numbers to generate 100 patients.
I tried to make it relatively smart, so you'll find that:
- Every patient has a unique name. Not a useful feature, but it was kinda fun doing it!
- Most patients should have a fair amount of symmetry between their eyes, just like real patients (ie you won't find many cases with a +6.00 OD and a -6.00 OS).
- The old glasses or autorefractor results won't be perfect (what would be the point of refracting?), but they won't be off-the-wall either (ie, autorefractor says +4.00 but you refract -6.00).
How is this data lacking?
- I didn't have the motivation to factor in accommodation. I wrote a lot of code to make the virtual patients accommodate in ways you'd expect based on age. However, this data lists a starting VA's that do not take into account accommodation. As such, a 20 year old with +2.00 of hyperopia may show a starting VA of 20/80, but we all know this patient would probably be able to accommodate through that to a much better VA. As a cop out, I wrote a comment that these VAs were taken while the patient was cyclopleged. It's important to point out that this will not affect the process of refracting, only the initial VAs that are listed in the case "file".
- I didn't supply much history for the patients. Patients with cataracts or amblyopia will have some sort of statement related to their reduced BCVA, but the histories are not quite as involved as they are in the original case studies.
Each of these files has 100 patient cases. You can download them to your computer, than drag them into the directory that contains the contents of your CD. Rename the file you want to use to patient_files.xml (again, make sure you renamed the original so you don't overwrite it! ). When you start the refraction simulator it should pull in the data from the new file.
With 400 patients you'll have no excuse for not becoming refracting ninja!
OK, my body isn't that weirdly shaped. So why does it seem like I only have two choices when I buy a dress shirt at a normal-person store? My two choices seem to be:
1. A shirt that fits in the neck, but it's tight in the shoulders and has sleeves that are too short.
2. The sleeves are long enough, but the shirt is billowy and the neck is huge.
In essence, I feel like I'm being forced to choose between looking like a guy who's about to deliver a calf or a guy who's about to go wingsuit flying.
Historically I either wore ill-fitting clothes or went to Big & Tall stores, which seemed odd as I'm not big nor am I excessively tall.
And that's why I like shopping online.
Recently I was fondly reminiscing about watching Saturday morning cartoons. I'd wake up at the crack of dawn, go downstairs, and watch me some Bugs Bunny. I even remember waking up once and my shows weren't on, only to find out I was awake before cartoons even came on.
Watching cartoons was a pretty simple process, even for a 5 year old. It went something like this:
TV watching in 1977
So, I was thinking, why don't my kids do this? They certainly get up early enough on Saturdays, so that's not the problem. Well, for one, there's nothing special about Saturday mornings. There are cartoons available all the time, whether they're on cable, the DVR, the DVD player, etc..
However, I think the biggest obstacle is the modern TV watching workflow. It goes something like this:
TV watching in 2012
Now, if history is any indicator, my kids are going to be more tech-savvy than my wife and I. However, they're only four and two years old (and a one month old, if we're counting everyone) right now, and this is a little much for them.
So, what do they do on Saturday morning? Well, it goes something like this:
Entertaining kids in 2012: the iPad
I've had a big first world problem over the last few years. I work within a big clinic system and, like many large companies, our computer environment is locked down by our IT department. For me, this means I can't install or upgrade programs, use browser add-ons, or even visit certain websites (although there's no rhyme or reason to this - some seemingly innocuous sites are inexplicably banned while others, like FaceBook, are OK. And no, I haven't even tried visiting the, er, red light district of the web from my work computers). Worst of all, I have no choice over my platform or browser. This means I live in a Windows XP / Internet Explorer 8 purgatory.
The thing is, I'm not even asking for much. When I'm at work I expect to work. I'm not looking to play Farmville while my patients wait for me. I just want to do the some normal day-to-day things that I dont feel are unreasonable, such as checking my Gmail account or creating spreadsheets or documents in Google Docs. However, activities like these result in so many freezes, crashes, and lost emails and documents that I've found myself avoiding doing anything productive when I do get a chunk of free time.
Then I had a revelation - I can't install another browser, say Chrome, on my work computer, but could there be another way to run it on that computer? I recalled hearing about the existence of mobile versions of Chrome and Firefox, and I decided to give it a try. First, I downloaded the portable version of Chrome from Portableapps.com to a USB flash drive.. Then, I unpackaged it, which turned to to be a little tricky because my work PC doesn't allow for the installation of applications, and my home Mac won't open a Windows application. Fortunately I had a really old Windows laptop in my basement - I pulled it out, fired it up, and unpackaged the application on my portable drive (all the time wondering how on Earth I ever built my website on that thing!).
The next day I went to work, plugged in my USB stick, double-clicked the browser, and . . . it worked perfectly! To be honest, I didn't expect it to. I thought my work computer would block the application from even opening. But it didn't, and I can't tell you how happy I've been. It runs like butter and hasn't crashed or even slowed down once. Even more exciting, it syncs with my home browser so all my bookmarks (and bookmarklets) are present, and I'm even able to use some of my favorite browser extensions. Furthermore, every time I boot up Chrome it opens up the tabs that I had open the last time I used it. I feel like I've been driving a work truck that wasn't allowed to go over 40mph and I was just upgraded to a, uh, really fast car. I no longer have to use the Internet like an animal.
Look - A flash drive shaped like a key!
Since I work from multiple locations I put my flash drive on my keychain - that way 1) I'll never forget to bring it and 2) I won't accidentally leave it in a work computer when I leave.
Now that I had a little taste of browser bliss, I wanted more. When I'm at home I've become very accustomed to using 1Password. Using the browser extensions it let's me easily (but securely) use strong passwords to access all my websites. Without having that on my work browser I've had to:
- pull out my iPhone an open open it
- open up the 1Password app (it syncs with my laptop via Dropbox)
- enter my 1Password password (and sometimes a second password)
- look up the password I want
- manually type it into the form on my computer (and we're talking about long passwords here)
And then, I discovered 1PasswordAnywhere, which is the perfect solution if you use Dropbox syncing with 1Password. Simply
- Log into the Dropbox website from the portable Chrome browser
- Open the 1Password.agilekeychain folder and then 1Password.html
. . . and you effectively get a 1Password app right there in your browser window! By entering your password you can view all of your logins and whatever secure information you've stored there. it's easy to copy a password and then paste it into a logging form in another tab.
In the end, I still miss the workflows, the shortcuts, the utilities and software that I have on my powerful home computer. However, being able to choose and customize my browser sure has made me a happy guy.
My mother-in-law suffered a very significant stroke about 5 years ago. She was never the same afterwords: She never regained her ability to communicate and eventually passed away in a nursing home.
Donna had been a very organized person. She loved playing the stock market and kept notes and logs of stock prices and whatever else financially minded people keep track of. Like all of us, she also had many online accounts. Luckily her usernames and passwords were pretty easy to guess and we were able to access the accounts.
It really got me thinking, though: If something happened to me, would my family be able to find the information they need? I decided I'd better make sure they could.
First, I'd better describe how I keep records and manage my online life.
For the last year I've been trying to go paperless. Its something that has always sounded appealing, but it wasn't until recently that I felt I had the hardware and software to make it practical. I don't want to go into too much detail about this, but if you're interested in learning more I would recommend David Spark's Paperless book - I wrote a short post about this a while back. The bottom line is, being paperless makes my life easier, but mostly because I know where everything is. However, if something happens to me, my family isn't going to find a file cabinet full of important records. That could be a problem.
I've also been trying to beef up the passwords I use online. Passwords are always tough: We want them to be secure, but we need to remember them too. However, using fluffy1 to log in to the website for my bank, my credit card, and Amazon.com just doesn't seem very smart anymore. If you're doing this, I suggest your read Matt Honan's story about how he got hacked, and hacked bad.
My solution to finding a balance between password security and password ease of use has been 1Password. Again, I'm reticent to go into great detail, but think of 1Passord as a vault for your passwords. You can create passwords like z2VU/7xkR, which is really really secure, but you don't have to remember it - you just have to remember the master password. If that sounds a little sketchy to you ("but, what if someone gets the master password?") , don't worry, it did to me too. However, the more I read up on 1Password the more I became convinced it was a great, safe solution. Much safer than the alternatives, at least, which include having the same password for everything or keeping a list of passwords that you have to pull out every time you need to log in.
So, I use secure passwords. However I realized that, just like the bad guys aren't going to guess that my bank password is z2VU/7xkR, neither is my family. So I decided to write a short note and place it a small fire proof safe (which, incidentally, I purchased after a patient told me how glad she was that she had one when her house burned down). If something happens to me hopefully this will make things easier for my survivors.
Here's the note I made. Of course I changed the passwords to protect the innocent (me).
Important!!
If something should happen to me, all the Web sites related to my personal and financial life are listed in an app called 1Password. This app also contains the usernames and logins for these Web sites. The 1Password app is on my computer, my iPhone, and my iPad. This passwords can be used to open it:
mypassword
Sometimes an additional PIN or password is needed to see more information. If so, they are:
1234
anotherpassword
If for some reason my computer and mobile devices are destroyed or lost, the encrypted 1password file is stored in dropbox. My dropbox account is "myname@email.com" and the password is "dbpassword". Using this file to access this information might be kinda tricky - it might require some help from customer support at 1password. Hopefully this will not be necessary (hopefully none of this is necessary, but you can't be too careful).
Of special interest, I use the online backup service Carbonite. If my computer is lost or destroyed all the files are backed up here (all my pictures, for example). Like everything else, the username and password can be accessed via 1password.
Of a personal nature, I've been keeping a journal within an app called Day One. This can be found on my computer and mobile devices. It uses iCloud for syncing so, again, if my you can't access my devices, this data can be restored via iCloud (in this case I'd contact Day One for support).
I'll probably refine it over time, and I'll need to update it when my passwords change. I kept the text file so it can be updated. However, I realized that having a unencrypted text file on my hard drive containing my most valuable paswords would pretty much defeat the purpose of this entire process. How to get around this? Well, I put it in the "secure notes" section of 1Password, of course!
Addendum:
My mom read this post and asked "Does [your wife] understand all this? I don't".
She makes a good point, because I refer to a lot of software and services that I'm very comfortable using but my family is not. A more detailed explanation would be very helpful. However, I still think this is a good start. If I tell myself I needed to write a long, step-by-step explanation on how to recover this information, well, I know I'll put it off. We all tend to do this, especially when 1) we feel no urgency and 2) it involves something we're not comfortable thinking about.
In short, It's better to do something simple today than do nothing at all. There's enough information here to accomplish what I want. In the worse case scenario, my family would need to seek the help of a tech nerd. That's acceptable.
did a little experiment looking at the size of eye drops in about 1999, and I thought I'd dust it off and share it here. A couple things to keep in mind:
This isn't a peer-reviewed paper
Some time has passed and I wouldn't recommend looking too closely at the raw data. After all, I suspect the dropper tips used in my experiment have been redesigned several times in the last 13 years and measurements of drop size would not apply to today's bottles.
It's hard for me to believe, but the medical treatment of glaucoma has greatly changed since I did this experiment: Prostaglandins were not even available at the time of my study.
However, the overall conclusions are still valid. There can be considerable differences in drop sizes, which can make the length of time a given drop will last quite variable.
So, without further adieu,
[insert dramatic 20th Century Fox movie music here]
Days of therapy expected from promotional samples of antiglaucoma medication based on drop number and size.
Todd M. Zarwell OD FAAO
Abstract
Objective: To evaluate the duration of therapy of five antiglaucoma promotional samples.
Methods: Five different antiglaucoma medication promotional samples were obtainedfrom laboratory representatives. Three subjects dispensed 10 drops each onto ananalytical scale. The mean drop volume of each medication was calculated. In addition, the fill volume and amount of medication wasted by the patient was calculated. Fromthis data the expected days of therapy for each medication was determined This was then compared to what an accepted "rule of thumb" equation would have predicted. Results: This study found that four medications (timolol maleate, dorzolamide, brimonidine tartrate, and a timolol / dorzolamide combination) provided a longer duration of therapy than the "rule of thumb" would have predicted while one (betaxolol) providedless than predicted. The Alphagan bottle had the most wastage while Trusopt had the least.
Conclusion: There is considerable variation in the duration of therapy of glaucoma medications in sample form. This may be due to differences in sample size as well as differences in drop size between the medications. The professional providing these promotional samples should be aware of the duration of therapy of each medication toensure continuous treatment until further follow up or additional medication can be obtained.
Key words and phrases: Antiglaucoma medications, ophthalmic promotional samples, timolol maleate, dorzolamide HC1, brimonidine tartrate, betaxolol HCl.
Introduction
When attempting to determine the drop volume of commercially available glaucoma medications, clinicians sometimes use the "rule of thumb" equation that every milliliter of medication will yield approximately twenty drops.
Using this formula the medical vision care provider can estimate the number of drops that a container of medication will yield by multiplying its volume in milliliters by 20. Furthermore, the number of days of expected therapy from that medication can be determined by dividing the number of drops by the number of drops used per day, taking into account the dosing schedule and the number of eyes that are receiving drops.
Assuming 20 drops per milliliter assumes a 50 microliter drop size. However, a study of 20 antiglaucoma medications by Lederer and Harold found a mean drop size of 39.0 microliters and a range from 25.1 to 56.4 microliters.1 This indicates that assuming the 20 drops per milliliter rule will greatly underestimate the number of drops and consequently the duration of therapy that can be expected from antiglaucoma medication. In addition, it is apparent that any one formula is not adequate to determine the drop size of all antiglaucoma medications as considerable variation exists.
A number of studies have been performed to determine the duration of therapy of commercially available antiglaucoma medications. 2,3 Stewart and associates considered duration of therapy, average cost, and wastage of product in determining the expected yearl cost of glaucoma therapy.2
To the author's knowledge there has been no investigation of the duration of therapy expected from promotional samples of antiglaucoma medication. This is likely due to the fact that these samples are free of charge and are of no direct expense to the patient or the clinician. However, the knowledge of how long a promotional sample of medication will last may provide useful information to both the medical vision care provider and the patient.
The purpose of this paper is to determine the amount of medication that is provided in these promotional samples. The quantity of each of five commonly distributed sample products was determined from which the days of therapy was extrapolated, taking into account drop size and wastage of product.
Methods
Five promotional antiglaucoma medication samples were obtained from local laboratory representatives. The medications included a 5 ml bottle of Alphagan(brimonidine tartrate .2%), 2.5 ml bottles of Trusopt (dorzolamide HC12%), Cosopt (a dorzolamide HCl and timolol maleate combination product), and Betoptic S (betaxolol HCL.25%), and a 1.25 ml bottle of Timoptic XE (timolol maleate .5%).
Three subjects, all optometry students, instilled 10 drops of each medication at room temperature onto an analytical scale. To prevent fatigue, subjects were instructed to pause ten seconds between drops, at which time the size of the drops was recorded in grams. Subjects were asked to use the method of instillation they were most comfortable with. Because previous research has indicated that the dropping angle can significantly affect drop size, the analytical scale was elevated to a height of five feet to best estimatethe technique of instilling drops into the eye.4 The scale used was a Viscount Plus Series II sensitive to 0.001g.
For each medication the mass of the individual drops was measured, from which an average and a standard deviation were calculated. Calculations for wastage of medicine and percent usability were performed using formulae identified by Stewart and associates, as described below.2 Total mass of medication was calculated by finding the difference between the empty and full bottles. This value was compared to the actual amount of fluid dispensed to arrive at the amount of medicine wasted using the following formula:
Medicine wasted - total bottle mass - mass of dispensed medicine-unused medicine
Sources of wasted medicine include the fluid that rolled down the dropper tip alter dispensing and any extra drops that leaked out of the bottle after dispensing the intended drop.
The percent usability (percent dispensed correctly versus wasted) of a medicine was calculated by the following formula:
Number of days of bilateral therapy was calculated by the following formula:
Statistical analysis included a two-sample t-test comparing the difference between the drop size of each medication with each of the other four medications. In addition, a two-sample t-test was also calculated to compare the difference between the three different subjects.
Results
The results of the mean drop size are shown in Graph 1. No significant difference was found between the mean drop size of Cosopt and Trusopt or between Betoptic and Timoptic XE, but a significant difference was found between all other medications (p<0.005). The largest mean drop sizes were observed with Betoptic (49 mg) and and Timoptic XE (47 mg), while the smallest drops were observed with Cosopt (31 mg) and Trusopt (31mg). Alphagan had a 37 mg drop size.
Graph 1
The percent usable value for each medication can be seen in Graph 2. The largest percent usable drug (least waste) was Trusopt (97.7%), while the least percent usable drug (most waste) was Alphagan(83.2%).
Graph 2
Graph 3 shows the expected days of therapy for each medication. A twice-a-day therapy was assumed for every medication except Timoptic XE, which was assumed to be once-a-day. As would be expected due to the larger bottle, the 5 mL Alphagan sample provided the most days of therapy: 30.1 days. Among the 2.5 mL, bottles Trusopt (23.9 days) and Cosopt (22.1 days) had a similar length of duration while Betoptic, which had the largest drop volume, yielded less days of treatment (9.9 days) than the 1.25 mL Timoptic XE (15.6 days).
Graph 3 also illustrates the expected days of therapy using the 20 drops/mL rule. All but Betoptic yielded more than the predicted duration of therapy.
Graph 3
No significant difference in drop size was found between the three subjects (p<0.001).
Discussion
Oftentimes clinicians determine how long a medication will last for a patient based upon the number of drops that can be expected per milliliter of medication. It is often assumed that 20 drops of medication will amount to a volume of 1 mL.
The results of this study indicate that such assumptions may lead to errors in the estimation of duration of therapy. Of the five promotional samples tested, this assumption underestimated the duration of treatment of four of the medications (Timoptic XE, Alphagan, Trusopt, and Cosopt) and overestimated the duration of treatment of one (Betoptic S).
Other studies have found similar results for commercially available (not promotional samples) antiglaucoma medications. Ball and Schneider point out that the differences in duration of treatment may result in a wide variation in cost of treatment for the consumer. As some physicians assume the potency of many glaucoma medications to be equivalent, cost may be a prime consideration when deciding upon a treatment for an ocular hypertensive patient.5 Because promotional samples are free to the consumer, cost of therapy is not a major concern when beginning treatment with these products. However, knowledge of how long the medication will last is useful for informing the patient how much time he or she has to obtain more so that no treatment is missed. In addition, it may be particularly useful in a system that provides medications for the patient, such as the Veterans Affairs or a managed care group. Comparing how long a sample of medication lasts a patient to how long it is expected to last based on this study's results may be useful in determining a patient's compliance.
Promotional samples come in a variety of different volumes, which, as expected, results in a variation in the duration of therapy provided. In addition, there is also a variation in drop size for each of the medications. As current research indicates that a larger drop does not necessarily have a therapeutic advantage over a small drop, the main consequence of an increased drop size may be a decreased number of days of treatment.6,7 According to Brown, the factor most responsible for drop size is the diameter of the bottle's dropper tip.8 Other determinants may include the temperature and the viscosity of the fluid, which may offer an explanation as to why a suspension such as Betoptic S has a different mean drp size than a solution such as Alphagan.
Obviously, an increase in drop size will decrease the number of drops and therefore the days of therapy a medication will provide. For example, in this study both Betoptic S and Cosopt had a 2.5 ml volume. However, Betoptic had a 58% larger drop than Cosopt, which consequently yielded 55% less days of therapy.
There are several clinical considerations that may interfere with extrapolation of this stud's results. For instance, the amount of medicine wasted can be much higher when instilled into the eye as compared to an analytical scale due to the increased difficulty with this process. In addition, because the mean of a glaucoma patient is significantly older than the subjects of this study, there is a greater likelihood of decreased fine motor control and therefor a greater amount of wastage.
Conclusion
Promotional samples of antiglaucoma medications come in a variety of sizes. The samples in this study came in quantities ranging from 1.25 mi to 5 ml. In addition, there is also considerable difference in the mean drop size of these medications. In this study,the wide range of both these variables resulted in durations of therapy ranging from 9.9 days to 30.1 days.
When dispensing promotional antiglaucoma samples, the medical vision care provider should be aware that this range exists. Knowledge of the duration of treatment will enable the clinician to either provide enough medication to supply the patient until he or she can obtain more or to schedule follow-up before the patient's supplies are exhausted.
References
1. Lederer, CM., and Harold, RE.: Drop size of commercial glaucoma medications. Am. J Ophthalmol. 101: 691, 1986.
2. Stewart, WC., Sine, C., Cate, E., Mirmo, G.E., and Hunt, RH.: Daily cost of beta-adrenergic blocker therapy. Arch. Opthalmol. 115: 853, 1997.
3. Meyer, M.A. and Savitt, M i . : A comparison of timolol maleate and levobunolol. Length of use per 5-ml bottle. Ophthalmol. 101: 1658, 1994.
4. German, E., Hurst, A., and Wood, D.: Eye drop container delivery: A source of response variation? Ophthalmol. Physiolol. Opt. 17: 196, 1997.
5. Ball, S.F., and Schneider, E.: Cost of beta-adrenergic receptor blocking agents for ocular hypertension. Arch Ophthalmol. 110: 654, 1992.
6. Shell, J.W. : Pharmacokinetics of topically applied ophthalmic drugs. Surv. Ophthalmol. 26: 207, 1982.
7. Petursson, G., Cole, R., and Hanna, C.: Treatment of glaucoma using minidrops of cionidine. Arch Ophthalthol. 102: 1180, 1984.
8. Brown, RH., Hotchkins, M.I., and Davis, E R : Creating smaller eyedrops byreducing eye dropper tip dimensions. Am. J Ophthalmol. 11: 460, 1985.