Case Study
topic: The responsibility of an optometrist is not only to check vision, but also to check binocular function.
by Dr.Loft ,O.D
public 22 July 2023
Introduction
Yesterday, we talked about “numbers value in refraction prescription" and talk about how it is easy to look the final numbers because it’s look just numbers, but it is difficult to get the numbers (if it is easy, optometry would not have to be studied for 6 years). This is something that people with intelligence would be able to see. And if the numbers only have the eye prescription number from the refraction, it would be like buying one shoe and wearing it.
The numbers for the case today , we are going to talk about today are simple:
OD +0.25 -0.25 x135
OS 0.00
Add +1.1D
These numbers are look so simple, but if you were to prescribe for them, you would be sick of making claims.
Case History
A 45-year-old female patient came with the symptoms of not being able to see clearly at a distance with each eye, but when she looked at two eyes at the same time, she would see double images in some angles, especially when she turned her eyes to the left. This happened sometimes, but not always, and she had been feeling this way for many years.
She could cope with it by tilting her head to the left, which made her eyes feel more comfortable. Or, she could close one eye to see better. When driving, it was very difficult for her to look at the left and right mirrors, and she had difficulty judging the distance when braking or changing lanes. She could cope with this by driving slowly, turning on the turn signal early, and waiting for sure before changing lanes.
She did not have a headache, but she was annoyed by the double images in some angles at some times.
She had consulted with many doctors, some of whom said to operate, while others said that the angle was too small to operate. So, she came to consult me for more advice.
Preliminary eye exam
VAsc : 20/20 OD,OS,OU (but had to tilt the head to see clearly)
Cover Test : Right Hyperphoria w/ mild exophoria
Refraction
Retinoscopy
OD Plano (0.00) ,VA 20/20
OS Plano (0.00) ,VA 20/20
Monocular Subjetive
OD +0.25 -0.25 x135 ,VA 20/20
OS Plano ,VA 20/20
BVA ; Diplopia ; When the patient saw double images, the BVA could not be performed immediately. The binocular function test had to be done first, and then the BVA could be done later.
Binocular Function
Worth-4-dot : Diplopia , fuse w/ 5 prism base up OS + 1 BOOD
Associate phoria: 5BDOD ,R-Hyperphoria (w/o horizontal phoria)
Horz.phoria : Ortho (VonGrafe’s technique)
Vertical phoria : 5 BUOS (R-hyperphoria w/ VonGrafe’s technique)
Vertical phoria : 5 BUOS (R-hyperphoria w/ Maddox Rod)
**Park-3-step : Right hyper deviated / left gaze worse /right head tilt get worse
Result : Right Superior Oblique Palsy (suspect)
Binocular at near 40 cm
Vertical Phoria : 5 BUOS (R-hyperphoria)
BCC : +1.00D
Assessment
1.Mixed hyperopic astigmatism OD, Emmetropia OS
2.Pre-Presbyopia Suspect
3.Right Superior Oblique Palsy
Plans
1.Full Rx
OD +0.25 -0.25 x135
OS Plano
2.Prism Correction
Rx: 2.5BDOD / 2.5BUOS
3.Refer Neuro-ophthalmologist and Neurologist to rule out brain
Analysis
Refraction
The patient's uncorrected vision is clear, but they have diplopia, which is making it difficult for them to live their life.
Binocular Function
The patient's history clearly indicates that they have vertical heterophoria, but it is necessary to differentiate which eye is deviated and what muscle is likely to be involved.
- Worth-4-dot : The patient has diplopia.
- Associate phoria : The patient has right hyperphoria of 5 prisms.
- Dissociate phoria : The patient has right hyperphoria of 5 prisms.
- Maddox Rod : The patient has right hyperphoria of 5 prisms, and in addition, the patient sees that the horizontal line of the right eye is tilted, indicating that the muscles of the right eye are not balanced, causing the eyeball to slightly lift up and twist.
- Park-3-Step : The patient's right eye deviates, the left eye gaze worsens, and the right head tilt worsens, indicating that the superior oblique muscle of the right eye is weak, but the cause is unknown. The patient needs to be referred to a neurologist for further evaluation.
The patient consulted with 3 doctors about surgery, but most of the doctors did not recommend surgery because the angle was too small and surgery may not be effective. The patient then consulted with me. The correction of diplopia at an angle of heterophoria of less than 10 prisms can be easily corrected with a prismatic lens, which can allow the patient to live a normal life. However, the cause of the weakness of the muscle group must be determined by referring the patient to a neurologist to check for any neurological abnormalities. If there is an abnormality, the patient can be treated at the root cause. If there is no abnormality, the patient can be reassured.
The patient's case of diplopia caused by eye muscles ended well.
The Point is…
If optometrists only work on refraction and not binocular function, it would be like a monk who only observes the five precepts out of the 227 precepts. And if they only observe the five precepts, then they would say that they are better than laypeople, and then sell things to compete with laypeople (a metaphor). This would not be appropriate, because as a professional, working like just a tradesman, and saying that you are better than people in the business world, just because of a sticker on the wall, would also be inappropriate.
Some people say that they are employees in a glasses store, and the store does not give them enough time to work at their full potential, so they do not do it (becoming a talkative person who is only good at academics). That would not help much, because no one drags us along. We walk ourselves, so we have to accept the condition.
Therefore, when working for someone, we must look at the attitude of the glasses store. Do they see glasses as a product (bought and sold) or as a device used to treat or solve problems for patients?
Because different attitudes will lead to different working styles (but 98% of them only see glasses as a product that is bought and sold, and do not understand or have any inner knowledge about the visual system. Whatever can be sold, has a profit, and is a business that makes money, is considered to be good in the eyes of a businessman, and sees vision problems as a type of product).
Therefore, let's review the precepts of optometrists.
The precepts (duties) of optometrists, as stipulated in the Acceptance of the Practice of Medical Arts by Optometry, Section 31 of the Medical Arts Practice Act B.E. 2542 by the Minister of Public Health, defines the duties of optometrists as follows:
- Check the binocular function system.
- Check and test the eye movement system.
- Screen for abnormal vision for referral to a doctor as appropriate.
- Solve vision problems by dispensing lenses and vision aids.
- Eye muscle training.
- Use corneal staining agents and local anesthetic drops (Fluorescein Dye Strip).
- Measuring vision in conjunction with the use of mydriatic eye drops under the control of a medical professional.
There are 7 precepts. If you take only precept 4, which is refraction, to sell glasses, and leave binocular function, it would be a bit rough for someone in the profession of optometrists, and then to say that they are better than others would not be fair, especially for patients with vision problems who hope to rely on optometrists, and then their hopes are destroyed by measuring glasses, arranging vision, and promoting the sale of glasses. Is it appropriate with the dignity that exists?
I have always adhered to the precepts of optometrists since I started Loft Optometry. There is only one precept 7 that I have not done, because optometrists are not yet able to be a medical facility (I don't know who is interested, but it is definitely not the public). And to be honest, I am not comfortable being under the control of another profession, because optometrists are not technicians who only collect data and pass it on. But the profession of optometrists is the highest degree in the field of vision and the vision system. You must be able to collect data, analyze data, diagnose data, and treat yourself, and be responsible for all of your actions. There will be exceptions only for problems with physical pathology that are beyond the scope of the work of optometrists and need to be referred to medical treatment (do not overdo it).
In my opinion, the responsibility of optometrists is not just "measuring glasses", but measuring vision, checking the binocular vision system, and checking eye health to look for lesions. It is not just about measuring glasses and then selling glasses. But I use lens and glasses devices as devices or tools to treat problems of the vision system for patients.
And for me, the word "measuring glasses" is a form of "bullying".
It is an attempt to devalue other professions with a deep mindset that "just glasses". I am not okay if optometrists accept this devaluation and do not feel anything.
When optometrists are a professional job, the cost that arises is the cost of treatment in the form of a product, which is a frame and lens. Therefore, the cost varies depending on the difficulty of the vision problem and the vision system, and it is not possible to compare prices with general stores. Because the standpoint of the work is completely different. Only the end product that comes out is similar in appearance (just glasses), but the function is definitely not the same (not just glasses).
Thank you all for read until at the end.
Dr.Loft,O.D.
If you have any questions about visual problems ,don’t hesitate to contact me by Chanel…
Loft Optometry
578 Wacharapol rd. ,Tharang ,Bangkhen ,BKK 10220
Mobiel : 090-0553-6554
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Glasses Spect
Frame : Lindberg Thintanium 5502 (custom spec)
size48#18 , temple 850 145 classic color U12/U12
Lens : Rodenstock Multigressiv Mono B.I.G. Norm Plus2 ,P1.1
Coating : Solitaire Protect Pro 2 w/ extra clean
tint : Gradient Chestnut Brown 40%-0%
