prof-barrett3
If you are reading this article right now and wondering why my website:
https://sites.google.com/view/haigis
was removed from the haigis section, the answer is quite simple. It is because of the following article:
" Accuracy of Intraocular Lens Formulas in Eyes with Keratoconus "
It seems that Prof Barrett objected to my article " Prof barrett2. "
Unfortunately for me, I was completely unaware that the following article even existed:
" Accuracy of Intraocular Lens Formulas in Eyes with Keratoconus "
and paid the price for it, in terms of being banned from the haigis section.
Such an article like this one, presents huge problems for someone like me, because , before I can present my formula, I must be able to demolish the arguments of the authors of this article.
Where do I start ?
The full article is available from the American Journal of Ophthalmology at a cost of $35.95. It is not worth paying that amount for it and it can be obtained for free by searching around on the internet.
In the abstract it was concluded that the Barrett Universal ll formula was superior to the rest of the formulas in mild to moderate keratoconus cases and all of the formulas that were tested resulted in a hyperopic surprise.
To find out the real truth of the matter, one must study the full text.
In the full text one finds that:
None of the authors of the article actually participated in any of the surgical work themselves. In fact, all of the surgery was carried out by eye surgeons at the Wilmer Eye Institute at John Hopkins Hospital, Baltimore, Maryland, USA.
There seems to be an apparent lack of detail exhibited in this article. Why was it that each eye surgeon did not write a research paper on each patient which they treated, as was done in the case of the four cases presented on my website?
https://sites.google.com/view/keratoconus3
Instead of which, all 101 cases of keratoconus were all lumped in together. It was not as though all of these patients arrived on the same day. They presented themselves over a period of 4 years and during that time cataract operations on persons suffering from keratoconus were a newsworthy event.
There seems to be a lack of detail as to distance vision and close vision of each of the patients involved in this study, following surgery. 17 of these patients were excluded from the study because they did not fit the requirements of the authors. They could have quite easily been included in the study, except that they would have spoiled the statistics for the authors.
The results seem to be heavily skewed in favour of mild keratoconus. To illustrate this point, I refer to the number of patients in each category. We find 46 patients in the mild category, 22 patients in the moderate category, 5 patients in the severe category and no patients in the ultra severe category. To be fair, there should have been, say 20 patients in each category. The 5 patients in the severe category were not even included in the study. Little wonder that the authors obtained the results that they wanted.
In this study, as mentioned previously, it was found that all of the formulas that were tested resulted in a hyperopic surprise. By "hyperopic surprise " , I presume that the patients became longsighted. If this is the case, then this is a serious admission to be made by the authors, because the loss of close vision to a person suffering from keratoconus is a catastrophic event. People with keratoconus rely heavily upon their close vision and without it they are completely lost. Emmetropia, or distance vision has little value to a person suffering from keratoconus. Unfortunately, this loss of close vision cannot be corrected by reading glasses.
In 2010, the UK Royal Collage of Ophthalmologists adopted as cataract surgery outcome benchmarks that 85 per cent of post op refractions end up within 1.0D of target and 55 per cent within 0.5D. These benchmarks have been well exceeded in several subsequent series around the world, leading some to recommend raising them to 90 per cent within 1.0D and 60 per cent within 0.5D
What did the authors of the article manage to achieve? The Barrett Universal ll formula, their best formula, achieved 52% within 0.5D in mild keratoconus and 50% within 0.5D in moderate keratoconus. Under the guidelines, this is classified as a failure and they did not achieve any results for cases of severe keratoconus.
No theory has been put forward by anyone as to how the Barrett Universal ll formula manages to obtain the value of the IOL that it finally decides upon in the case of a keratoconus patient. I note that nowhere in this article, is there any mention of the use of toric IOLs. Yet, the Barrett Universal ll formula is based on the use of toric IOLs. Otherwise how is the irregular astigmatism to be corrected?
All of science is based on some theory or other. First you have a theory. Then, you carry out numerous tests in order to verify your theory. If your tests do not verify your theory, then your theory is of little use to anyone.
In this case. there is no theory upon which all of the work is based on. All that the authors of the article have is a formula called the Barrett Universal II formula, which is a perfectly fine formula for normal eyes and they are trying to apply the same formula to abnormal, keratoconic eyes in the hope that it will work.
It is not the scientific way to approach a problem such as this one, by finding various formulas and seeing if anyone of them solves the problem, or if one of them is better than the rest of them, because, in science, we test theories, we do not test whether one formula is better than another. Otherwise, one is simply working in the dark and clutching at straws. One cannot find a solution to a problem unless one can find the cause of the problem.
Details of the strength of lenses inserted into each eye were entirely missing. Without such information it is virtually impossible to judge whether or not the cataract operation was a success or failure or what went on during the operation.
The whole point at issue in this matter is "What strength lenses are you going to insert into the eyes of a person suffering from keratoconus and requiring cataract surgery and how did you obtain that result ?" and the authors did not even bother to address that issue.
I know what the authors are going to say. They are going to say that you just measure the k values of the cornea and the axial length of the eye, pop the results into the computer and your answer pops out the other end, except it is impossible to measure the k values of the cornea of a person suffering from keratoconus and the axial length measurements are dubious as well.
The problem that the authors of the article face is that they were never involved in any of the surgery and they were never faced with the responsibility of choosing which lenses to use. Only the eye surgeons at the Wilmer Eye Institute were charged with that responsibility and they did not write the article.
Did the eye surgeons experience any difficulty in choosing which lenses to use and how did they eventually decide which lenses to use?
The problem that the eye surgeons face is that they are not scientists or computer experts. They are eye surgeons. They cannot be expected to solve problems that the best brains in the world cannot solve.
It seems as though, all of the eminent scientists and computer experts around the world have abandoned all of the eye surgeons and have left them to solve this problem on their own.
The article written by the authors is not much help either because it is just a conglomeration of complicated statistics and no busy eye surgeon would have the time or energy to plough through all of that information.
As there is such little useful information in the article, I have decided to devote some time into an investigation into the authors of the article, in an attempt to find out what the authors may have written in other articles on the same subject.
To find out about the authors of the article go to my website:
https://sites.google.com/view/prof-barrett4
From this website, you will find that the authors of the article and the eye surgeons were one and the same.
If that is the case, then, why didn't each of the authors of the article write their own research paper, giving a detailed account of any problems that they may have encountered during cataract surgery, instead of lumping them all together?
How many patients did Dr Jun operate on?
How many patients did Dr Ladas operate on?
How many patients did Dr Woreta operate on?
How many patients did Dr Srikumaran operate on?
I am not passing any judgement on any of the research work carried out by the authors. All that I am saying is that any of the research work that they may have ever carried out, would not have given them any special insight into finding a solution to this problem.
I have one slight advantage over the authors, in that , I suffer from the condition myself and have first hand experience of all of the symptoms, without having to read about them in some text book.
One can look through all of the research work carried out by each of the authors, only to find that none of the research work that they have ever carried out, has any relevance to the problem of what lenses to choose for a person suffering from keratoconus and requiring cataract surgery.
As for my attempt to find out what the authors may have written in other articles on the same subject, I did manage to find the following:
Intraocular lens calculations in atypical eyes by
Aazim A Siddiqui, and Uday Devgan
"There is a paucity of large studies that have considered which IOL formulae perform best in eyes with keratoconus. Traditional IOL formulae and keratometers are unable to account for corneal irregularities that are found in an eye with corneal ectasia. Therefore, it is recommended to use modern topographers which directly measure the anterior and posterior corneal power in combination modern IOL formulae. Newer generation formulae such as the Barrett Universal II, Ladas Super Formula, and the Hill-RBF are promising, but larger studies in ectatic corneas are needed."
These were the only comments that I could find on the subject.
This is somewhat surprising. Out of six authors, one would have expected numerous statements or opinions to be made on the subject, particularly as the study took place over four years. The whole research work seems to have been couched in secrecy.
Why is it that I could not seem to find Aazim A Siddiqui's qualifications anywhere?
Where are all of his scientific theories and mathematical formulas in relation to this matter?
Modern topographers aren't any better than the old keratometers. This is just not true because most eye surgeons around the world are still using the old keratometers and are happy with the results that they are obtaining from them.
Finding the correct IOL is not an exact science. Sometimes, even the best eye surgeons in the world, using the best equipment in the world, can get it wrong.
Furthermore, no mention is ever made of anisometropia. It is as though this problem does not even exist.
There are just too many questions left unanswered.
So far, only 73 people suffering from keratoconus have been tested and no one suffering from a severe form of keratoconus has been tested.
No one has managed to define what a successful outcome is.
The two big problems that the authors of the article will encounter is the problem of " hyperopic surprise," which they have already admitted to and the problem of anisometropia.
What is going to happen to any person suffering from a severe case of keratoconus? Are they going to be abandoned?
Before the Barrett Universal ll formula can be declared as a success, numerous, more cataract operations would have to be carried out by different eye surgeons and would it be possible for each eye surgeon to write out their own research paper, instead of lumping them all together?
Between 2014 and 2018 , a total of 73 people suffering from keratoconus were operated on.
The article was published on April 2020.
Since 2018 and April 2020, how many other people suffering from keratoconus have been operated on and where are their research papers?
Normal Eyes: average K = 44D
Mild keratoconus: average K < 48D
Moderate Keratoconus: average K 48D - 55D
Severe Keratoconus: average K > 55D
At the moment, we have three competing theories:
We have the theory, as espoused by the two authors, Aazim A. Siddiqui and Uday Devgan.
Their theory can be summed up in the following words:
".......... it is recommended to use modern topographers..................... in combination (with) modern IOL formulae. "
For convenience, let us call this theory the Siddiqui/Devgan theory.
I, bitterly oppose this theory for very good reasons.
Fortunately for me, a brilliant, new IOL formula maker, by the name of Jack X Kane, who has recently arrived upon the scene, appearing out of virtually nowhere, has provided all of the reasons for me.
I refer to his article:
"Accuracy of Intraocular Lens Power Formulas Modified for Patients with Keratoconus"
This was a relatively, recent, groundbreaking article.
In this article it was shown that the Kane keratoconus formula was more accurate than the Barrett Universal ll formula, thus, disproving, once and for all, the Siddiqui/Devgan theory, which states that only a modern IOL formula is required.
It was shown in this article that more than a modern IOL formula was required. In fact, an IOL power formula, modified especially for patients suffering from keratoconus was required, or better still, an entirely new Keratoconus formula was required.
Then, we have the theory as espoused by Jack X Kane. His theory is based on the Kane keratoconus formula.
Then, we have the theory as espoused by me.
My theory is based on an entirely, different Keratoconus formula.
Which is the correct theory?
Only time will tell.
Written by:
The Eye Enigma
17 February 2021
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