So yesterday I had the opportunity to visit Dr. Bob Lipski’s office to meet, ask questions, and learn retinoscopy directly from him. To say I learned a lot is a complete understatement. I had no idea what I was expecting from the visit only that I had key questions to ask. What surprised me most was how much better I feel with the material I have been reading about because Dr. Lipski was so hands on in his approach. Throughout the session I was able to ask my questions and we got more in depth than I expected. One of the most important parts of my visit is that I have a much better appreciation for what the patients who we are attempting to help are going through. I asked Dr. Lipski to put me in the patient’s seat. He put different lenses in front of my eyes and had me try to read the chart on the wall. He did this for spherical and cylindrical lenses so i could better understand astymatism. He also then showed me what it looks like as he cycles through lenses which get closer to clear and crisp vision. One thing that shocked me is that Dr. Lipski indicated that he did not like using the phoropter; he said that it was just a fancy tool that apparently causes him to under-minus people a lot because of the distance between the patient’s eye and the lenses in the phoropter. I think this is an important factor to consider with our diagnostic tool. I asked him to show me what kind of difference such a distance makes just to get an idea of the magnitude of the problem. He took two lenses in front of my eyes and told me to focus on the letters on the chart. He then proceeded to move one of those lenses away from my eye towards the screen and I watched the image get blurrier until I could barely make out a blob of a letter. Dr. Lipski said that this sort of error is worse for higher powered lenses like and 4 diopters in magnitude and above. This is good news for the pinwheel and whale-bone design as the maximum lens power is a magnitude of 3 diopters. I got to see that even with 6 inches between lenses of 3 diopter magnitude, the distance that that difference made was not that extreme. The scenario is when the lenses are stack one on top of the other; considering that the pinwheel causes a separation from one lens to another by a small amount (maybe .5 cm at most) and the lens powers are small in magnitude, I am becoming more confident in the potential of the pinwheel. It is important however that we make sure that with that device the patient has the handle part and holder on their face or very close to it to minimize the error caused by the distance between the lens and the eye.
Another thing I questioned Dr. Lipski about is the Duo-Chrome test as we are looking into it as a possible option for diagnosis. Apparently he uses this test quite frequently for his patients as a means of refinement of his diagnosis. He first uses the phoropter to get a general idea of a person’ s prescription, then uses retinoscopy and finally the duo-chrome test to refine the whole diagnosis. The test entails asking the patient to look at a target which has a solid red background on the left and green on the right with bold black letters centered across the middle. The patient is asked which black letters (which side) do they prefer based on how bold, clear, black, and bold the letters were. I paid attention to his diction here as from my readings I knew that the duo-chrome test results can be thrown off if a patient chooses a side simply because the background is brighter. I brought his attention to what he had said and he emphasized the importance of giving clear directions so that patients know what to look for. He said that this is especially important for patients in Guatemala because of the language barrier and the fact that some of the people have never had any sort of eye examination. This surprises me a lot because of the doubt from a couple sources about the duo-chrome test and its reliability. I asked Dr. Lipski what he thought of using the test as a more general form of diagnosis and he said that it was made simply for refinements. He went on to explain that if the eyesight is bad enough and a patient cannot even make out the letters on the target; when this happens both sides look equally atrocious and you would be left blind guessing. Considering that the pirate scope can give a general idea of prescription, perhaps we could use the duo-chrome test for refinement purposes for our own diagnostic procedure. I was more skeptical of the test itself because it is strange to thing that you can see the black letters more clearly based upon a color background but Dr. Lipski had me experience this first-hand with trial lenses. There was defintely a distinct difference between the letters on the green versus red background. He was insistent on saying that green is ok for a patient to prefer, red is bad knews, but no preference is exactly what you want to hear. From this, I think it is worth the effort to make some sort of target to use with the pirate scope, scaled correctly, to see what kind of difference it will make in our accuracy with that device.
Retinoscopy 101 Experience
One of the purposes of me going to see Dr. Lipski was to learn to perform retinoscopy so that I can verify results once testing of the new devices and/or new processes is begun. Plus it would be incredibly beneficial down in Guatemala for me to have that skill. Before the visit, I had done extensive research on retinoscopy and the process of diagnosis; however, reading and doing simulators does not really do justice to the challenges of performing it in person with a patient.
We started off easy as Dr. Lipski had me first use a model eye to get a better picture of how retinoscopy actually worked within the eye. He had me look at a the conditions of a normal eye where the light focuses perfectly on the retina after passing through the lens of the eye. He then selected extreme myopic and then hyperopic lenses so I could learn to recognize with and against motion with the retinoscope. The model eye was extremely large and the refractive abilities of the lenses so strong than it was not hard to pick up the patterns I was supposed to see. He then proceeded to show me what astygmatism looked like with the retinoscope by putting a cylindrical lens into the model. Using the streak retinoscope’s rotational cylinder in the base, I was able to orient the light streak along the two astygmatic axes. Dr. Lipski explained that the goal of retinoscopy is to neutralize the refractive error of these axes which are almost always perpendicular.
When they are not, you get a scissoring effect, however he assured me that it is rare to occur. If the scissoring effect is observed then glasses cannot be used to fix that patient’s eyes. I asked Dr. Lipski about how common astygmatism was and he answered that almost everyone has some form. He said that in Guatemala, astygmatism is a huge problem and that most of them have ‘with the rule’ astygmatism meaning the axis is 180 degrees. Conversely ‘against the rule astygmatism’ is at 90 degrees but is less common. I then proceeded to ask about how to recognize cataracts and other abnormalities in the eye while performing retinoscopy and how to get around them. By using this one plastic lens and a marker on the model eye, he simulated the conditions of cataracts and had me pass the retinoscope over it to see how ‘funky’ it the reflex appeared. Dr. Lipski laughed a little and said that there was no magic to it but that you simply do the best that you can to see around or through the issues. You cannot always help a patient and when that happens you simply have to move on to those that you can.
Anyways, the purpose of my visit was to learn spherical retinoscopy not diagnose astygmatism. He had me pay attention to the speed, brightness, direction, and width of the reflex as the retinoscope is flashed across the eye. Just like my readings indicated, Dr. Lipski explained that it was easier to look for width motion first and then move on from there by adding more positive lenses. When the reflex is slower and dimmer, the refraction is far from neutralization. Thus the goal is to cycle through lenses until the speed increases (to infinity), you have slight width motion, the line of the reflex is at its peak (as in no line, just illumination of everything), and the reflex was at it’s brightest. This is when you recognize the correct prescription. After doing a couple diagnoses with the model eye, he made it much more challenging.
Next Dr. Lispki took a seat in the patients chair and use the retinoscope on his eyes so that I could develop the proper techniques. He said that one of the most important things is alignment; the beam of the retinoscope needs to go straight through a patients pupil. Dr. Lipsky had me pivot around different ways and I saw how easy it is to make a mistake in recognizing the reflex properly if you are not properly centered. He then instructed me on working distance and how with spherical prescriptions, it is of the utmost importance to subtract the working distance at the end. From my previous research, I knew that this is because you are looking for a person’s prescription for focusing at infinity and not at the distance you make the diagnosis thus it must be subtracted. The working distance is usually 1.5 diopters but he said that since I was shorter, I could be all the way to the 2 diopter range but was not entirely sure. Anyways, he allowed me to experiment with the retinoscope to see the actual reflex and to get more used to using the tool. As I was doing this, Dr. Lipski pointed out that I had the tendency to lean in too much which affects the working distance, a common mistake for a beginner to make; thus I adjusted and continued.
While I was moving and rotating the beam of the retinoscope across his eye, I noticed that the streak and the reflex did not always line up. From my research, I knew that this meant he had astygmatism so I inquired about it once I found the proper axes; he was surprised I was able to detect it and find the axis because his prescription is so light and the astygmatism so minor. As expected, retinoscopy on an actual person is much more challenging; the reflex is smaller to see, you have to balance holding the lens in front of the patient’s eyes without hitting them in the face or dropping it too low, you have to keep the retinoscope moving at a moderate pace so you don’t completely constrict their pupil, maintain your alignment with their eye and the light of the retinoscope, not to mention getting past the challenges caused by imperfections in the eye…Needless to say there is a lot going on all at the same time. However, after a little bit of toying around, Dr. Lispki said that he wanted me to diagnose his eyes but only focus on the spherical aspect.
As I worked through the process, I told him everything that I observed and he walked me through the process. It was challenging but a lot of fun. I was able to see the width and against motion as I cycled through the different lenses until I found neutralization. This point was not as clear and definitive as I had anticipated, however it could simple be from inexperience. Dr. Lipski then proceeded to put random contacts into his eye and repeat the process. The first contact I had a bit of trouble. After explaining my difficulties and what I was observing, Dr. Lipski said it was probably because he was staring too long and the contact became too dry. He said that dry eye is a common problem to run into and it can make diagnosis hard. He said that it is important to remind patients to blink and relax. From this he transitioned into another common problem encountered during retinoscopy; that is that patients need to focus on something distant behind the diagnostician. Patient (especially children) try to look directly into the light of the retinoscope. The second this happens, the diagnostic becomes almost impossible and then your working distance is messed up. Overall: don’t let it happen. While I was diagnosing his eyes, Dr. Lipski accidentally did this to me and I watched the once bright reflex turn almost orange and disfigured. The second that his gazed shifted behind me again, all returned to normal.
After this, I was able to diagnose his eyes with and match the prescription of the contacts he had put in his eye (this was the second random one). Dr. Lipski said that as long as one gets within 0.5 diopters of the ‘actual’ refractive error, then you have done your job. He said that this is a reasonable amount of error for our purposes based upon the needs of the people in the underdeveloped areas. I asked him at what refractive error does a person truly need glasses. His answer: a normal person can function with a refractive error of up to roughly 1 diopter.
Overall, this was an awesome visit and I would be glad to take advantage of his invitation to return and see how he handles patients. I want to listen to the kinds of diction and such so that I can get a better gauge of what is effective and correct in the diagnostic procedure and then mimic it for our own. Plus he told me I could work with actual patients and I can work on astygmatism because I was able to pick up the spherical quickly (or at least that is what Dr. Lipski indicated).
1. wait for lenses to come in (Dr. Lipski ordered them)
2. get more familiar with retinoscopy
3. make a properly scaled duo-chrome chart…then test
4. put together the prototypes and test them out
5. explore the cross-hatch target idea- Dr. Lipski sort of liked this one but I have a feeling that the duo-chrome is a better option if it is one at all
6. evaluate what direction is working best and test some more