Ask the Examiner - The Final Assessment 2008

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• Moby // Mar 14, 2008 at 4:14 am

  Can you tell me what equipment I need for the ODA station exam?
  Great idea by the way, thanks!

• RS // Mar 15, 2008 at 5:14 am

  Hello!

  If a child has exophoria at distance and near, is amblyopic in one eye with no strabismus, and on refraction you find a hypermetropic Rx. Would a cycloplegic refraction be required or is it ok to prescribe from non-cyclo refraction since there is no squint?

• WS // Mar 15, 2008 at 10:18 am

  Hi,

  if the px is exophoric, giving more plus wll increase the exo so i think its probs best to prescribe from non cyclo results uless the px is symptomatic!!

• Jane Macnaughton // Mar 17, 2008 at 3:45 am

  Moby
  For the ODA Station exam you will need to take along with you your ophthalmoscope for fundus examination, and the equipment you would normally use to do cover test and motility on a patient with a BV anomaly. 

  At one station you will be expected to perform Indirect on a patient using a Volk lens (patient and slit lamp are obviously provided ). If you have your own Volk that you are used to, you can take it along – otherwise there will be one at the station there for you to use.

  The College Guidance states: “You may bring your own Volk lens for the station requiring the use of a binocular indirect examination technique but it must be fitted with an ultra violet filter.  Volk lenses with ultra violet filters will be provided if you do not have your own.”
  Don’t forget to always take spare batteries or charged handles. You can’t leave the room to find spares.

• Simon Frackiewicz // Mar 17, 2008 at 12:52 pm

  Hi RS.

  You are correct to question the prescribing of hyperopic prescriptions to patients with exophoria, particularly bearing in mind that cycloplegic refraction can elicit larger amounts of plus than in the normal state. It follows that as plus lenses reduce accommodation, and thus accommodative convergence, an exo-deviation would increase with a hyperopic Rx.

  My first question is to ask why would such a patient be amblyopic? If strabismus is excluded as a cause, and supposedly there is no stimulus deprivation, then a refractive aetiology must be suspected. That is assuming that the reduction in vision is truly due to amblyopia - was the child sufficiently co-operative to ensure the vision was measured accurately? Could there have been a small-angled deviation which is difficult to see due to poor fixation?

  Secondly, if we assume that the reduction in vision is genuinely due to amblyopia, and that the patient is asymptomatic, the principal purpose of giving a prescription is to improve the vision rather than to manipulate the BV system. As such, the aim should be to correct any difference in prescription that may have given rise to anisometropic amblyopia, by giving the eye with the lower Rx a plano lens. Alternatively, if there is a significant degree of astigmatism, you could give the necessary correction but give the lowest amount of plus required to keep the mean sphere at zero.

  In any case, ensure you check the control of the deviation before and after prescribing a significant amount of plus to ensure you have not caused the deviation to decompensate.

  I hope this is helpful.

• KR // Mar 25, 2008 at 11:59 am

  where can i find the dates for the final assessments for this year?

• Joy Myint // Mar 25, 2008 at 2:13 pm

  The exam dates for the final assessment are on the College website:

  Try this link:
  http://www.college-optometrists.org/index.aspx/pcms/site.education.ex.sfr.fa.date/

• JY // Mar 26, 2008 at 3:19 pm

  Hi,

  I was asked to state the risk factors of Glaucoma in my second assessment which I stated with ease. However, I was totally thrown when asked to state WHY afro caribbeans were more likely to develop Glaucoma. I have not been successful in finding out the answer to this question and I would appreciate any suggestions?

  Another query I had was, how to test visual fields on a low vision patient. I know that on HFA, the fixation target can be changed to 4 lights to allow eccentric fixation and on the newer Hensons the fixation target can also be changed. But I was asked to find out in the LV clinic how it is done by my assessor. I asked the LV clinic staff when I attended my hospital visits but they do not know answer either. Is there anymore info that I can add to the above?

  Many thanks!

• Joy Myint // Mar 28, 2008 at 9:59 am

  RE: Glaucoma Q. To be fair the reasons why afro-caribbeans are more susceptible is a controversial subject. Some will say it is genetic (so family history is relvant) some say it is related to levels of pigment, some say that the disc is more susceptible to damage. There are other theories but none of them are definitive.

  RE: Low Vision Fields. Consider peripheral fields with a confrontation stick, Amsler, Goldmann perimetry, and Bjerrum screen.

• Nayan Chavda // Apr 2, 2008 at 7:55 am

  Hi, dont a question on the final assesment but more of a bv question.
  What do i do if:
  I have a px presenting with a longstanding alternating exotropia. They have good vision in both eyes, say 6/6 RnL, is RE dominant and has never complained of diplopia.
  do I
  A) Leave them as they are… (with the alternating exoT, as they have no complaints)
  or
  B)Try and use prims to make them binocular again as they have the potential to have BSV

  also does the size of the deviatoin matter when determining the managemnt options?

  many thanks!!!

• Simon Frackiewicz // Apr 2, 2008 at 10:44 am

  Hi Nayan,
  As the patient is asymptomatic, leave well alone. Such patients often have large deviations and would need such a big prism to make them binocular that it becomes totally impractical.
  In general size is important when determining management options, particularly when considering prisms or surgery.

• tasha // Apr 11, 2008 at 11:06 am

  hiya,

  was wondering if anyone could help me..how does the sale of ready readers differ if purchased from an opticians or froma supermarket for example? is the law aspect the same? do we have a responsibility if purchased from an opticians?

  thankyou..

• Peter Chapman // Apr 14, 2008 at 1:17 pm

  The supply of ready readers does not differ greatly whether purchased from a supermarkrt or optician. The sale is governed by the same aspects of law. However, as an Optometrist you have a professional duty of care and should ensure the sale of ready made reading spectacles are suitable for the patients needs.
  Ready reading spectcles are covered by their own specific standed BS EN 14138:2002.

• Dave E // Apr 23, 2008 at 6:37 pm

  Hi there, I am a NZ qualified and practicing optometrist with 8 years experience. I had 3 questions I wanted to ask regarding your course and the examinations to register as an optometrist in the UK.
  1) what are the dates for the examinatins this year (you’ve given the dates for the course but I wasn’t sure how soon afterwardst the actual exams are and how many days they are spread over)
  2) what happens if I fail an aspect of the exams? Say I have a bad ret day (it happens sometimes!), or a blank out? Do I get the chance to repeat the exam again immediately or do I have to wait until the cycle of exams are held again whenever that would be (6-12mths)?
  3)finally, like most optoms I know here I have developed my own method of subjective refraction. It works very well for me and for my patients. However for the British examinations will I be expected to do subjective refraction in a prescribed manner, or will I be questioned if I perform it in my own way, or (hopefully) will I be judged solely on the outcome - how correct my prescription is for the patient?

  sorry to ask a flood of questions all at once, I really appreciate your help

  cheers - Dave
  New Zealand

• Aadil // May 14, 2008 at 10:28 am

  HI
  Im really concerned about the binocular vision and dispensing exams in jan 2009. can u recommend any text or information to help me? perticularly the dispensing exam because I have no idea of how to do the different measurement like refractive index for eg.and also to get info on lense materials, advantage and disadvantages.

  with regards to binocular vision, what wud be the best text to use for the exam?

  please help
  many thanks

• Aadil // May 14, 2008 at 10:30 am

  HI

  sorry to ask so many questions.

  with regards to dispensing is there a text take covers all there is to know about dispensing esp. for the exam?

  thank you
  aadil

• Jane Macnaughton // May 17, 2008 at 2:17 am

  Hi Dave and Aadil - I have put your comments nto the NonEEA thread and will answer them there

• m.s // May 18, 2008 at 12:27 pm

  hi i jave question regarding c.l- still confused about water content and dk dk/t, when looking at a table of c.l values and your chosing a lens type for say a px with dry eyes, do you choose a lens with a higher dk value, kindly explain.many thanks

• nat // May 19, 2008 at 10:56 am

  Hi,
  Just got a few questions about final exams next month:
  1) what do examiners tend to talk about in the 5 min clarification of the contact lenses exam? I dont understand what is meant by clarification, will they go into detail about the contact lens i use?

  2)when i advise my final order for my rgp is it acceptable to specify as BC/TD/RX? Or do i specify ALL base curves?

  3)what would examiners accept as a suitable method for calculating a presbyopic add? will it be accertable to use the tentative add equation?

  4)How will i measure TBUT in the eye i am fitting with a soft CL if no keratometer is available? Will tear height be enough?

  Apologies for all the question..

• Jane Macnaughton // May 21, 2008 at 3:36 am

  1. The clarification time is merely there to allow you both to conclude the exam. Questions will be brief if at all – for example, the examiner may look at your sheets and if there is something written down that is difficult to read, he may ask you to rewrite it. This exam is as objective as possible so no new information is asked for – it is certainly not a viva as it used to be.
  2. Specify precisely what the lab would need. In most cases what you have just suggested is enough.  However, you should be prepared to write a full RGP specification if asked.
  3. Do what you would normally do. Don’t bring out anything new for this exam. If you had a patient in practice who had genuinely lost their specs and you were unable to contact their previous optometrists what would you do? I advocate a tentative estimate based on age, history and working distance then put up something slightly lower. Say for example, I estimated a +1.50. then I would start with a +1.25. I then use binocular +0.25 flip. If its better, keep it, worse, remove it, etc.
  4. Keratometers are in most exam cubicles – it’s more the case that you are not examined on its use rather than the fact that they are not there for you to use. If you use a keratometer to estimate TBUT then you can use it (be careful off the time though as setting up will eat into your time). However, you should probably have another method of estimating TBUT in case (after all, what would happen if in your own practice your keratometer was off for a service and the one on the cubicle next door at work was in use?
  However, previoulsy in the Fit exam, the patient is assumed to be suitable for CL wear, which means the only measurements that you will need to take are those you would need to establish the size of the CL you are choosing. E.g. HVID, etc. However, I see in the recent guidelines that you are now required to assess the tears film. Let me check with the College and get back to you on that one.
  Apologies for all the question..
  No apologies needed. Good luck – not long to go now!

• Jane Macnaughton // May 22, 2008 at 4:43 am

  Hi nat - finally found the answer to the Tears film question’
  “Tear assessment is done in the Fit section, on the eye to be fitted with the RGP.”
  That helps with the issue of using fluorescein in the eye with a soft lens.

• nat // May 22, 2008 at 3:01 pm

  Many thanks! So i would measure Flurescein TBUT then..thankyou for clarifying!
  Back to revision…

• nat // May 24, 2008 at 9:57 am

  Hi, this isn’t really an exam question, more about pre-reg, but was wondering, if i fail my pqe’s in the summer and need to do resits in sept, do i legally have to carry on with my pre reg in july&august or can i leave my store?

• Krissy // May 25, 2008 at 11:54 am

  Good evening examiners.

  Hoping to ask you guys a few questions would appreciate if you could explain any of them to me or guide me in the direction of where I can get answers.

  1- What do I need to know about national eye care pathways for finals? Someone mentioned weci and pears? Im assuming these are referal pathways? what do they stand for?

  2-non arteritic ION: how does it normally present and how does it differ to arteritic? I know arteritic associated with GCA and requires emergency referral, but how does their presentatio&treatment differ?

  3-I have been revising Complicated PVD and reinal detachments and both present with the same signs i.e shaffers sign, weiss ring, flashes, floaters-are they they same? RD is when the retina splits from RPE, and pvd when vitreous splits from retina. So why are there signs the same? Can one occur without the other?

  4-Say if my px in my cdm exam has come with flashes and floaters. My management wotuld be to check pupils, pressures, va’s, dilate-fundus examn, slit lamp examination. Assuming all this is normal and no tears present, and a good, should I still refer for scleral indentation to be done at HES in case peripheral tear? or is it ’safe’ to advice px if any curtain over vision occurs fo straight to emergency?

  5-pre retinal haems which can occur in diabetes: what is there exact location, how do they disappear, and how long do they take to dissapear. Can vision still be adequate if pre-ret haem?

  6-Differntial prism!!! Can you please explain to me what i have to be able to do with this and possibly run through an example?

  Thankyou in advance for any kind of help you can give me.

• nyn // May 27, 2008 at 2:28 pm

  Had a quick question!!!

  I recently had a patient who was wheel chair bound, and thus had to test her at 5 meters. The rx was small approx RE -1.50/-1.00 *180, LE -2.00/-100*180, and was able to correct the vision to 5/5 RE and LE. My question is how does this relate to testing at 6 meters? Can I leave my results as 5/5 (tested at 5 meters) or should I convert it to the 6 meter equivalent (6/X), and if so, do I alter my final rx to account for the change in working distance.

  nyn

• Jane Macnaughton // May 28, 2008 at 1:55 am

  Nat
  Your terms of employment exist between yourself and your employer. Many will leave their current role and take up positions with other employers before completing their pre-registration year or their exams. I think in this case you are advised to talk directly with the College as circumstances vary between individuals.

• Jane Macnaughton // May 28, 2008 at 2:01 am

  Krissy: one at a time:
  WECI = Welsh Eyecare Initiative and PEARS Schemes exist in Wales only. So if you are not practicing there, then you will not need to have knowledge.
  National Eyecare Pathways – some good knowledge please – these are your ‘referral pathways’ and guidelines for ARMD, Low Vision etc. Detail may be found here. Also important is what happens at a local level to you with local schemes e.g. cataract and diabetes.

  Rest to follow

• Jane Macnaughton // May 28, 2008 at 2:18 am

  Nyn
  Testing at 5M:
  On the record card definitely leave it as 5/5. Because you tested at this distance. If you wish to convert it for convenience then do so and leave in brackets. 5/5 is 6/6/ after all.
  If you make any adjustments you do this to the final Rx not your subjective results – make sure that they are both contained within the record card.
  Technically, if you refract at a wd of 5M then your will have over-plussed your patient by 0.20 dioptres. So at the most you would want to reduce their distance Rx by 0.25. However, there are two arguments which would suggest that you leave alone: 1. If the patient is wheelchair bound then most visual tasks may be within a closer range rather than at infinity so there is an argument to leave this additional plus is (for what its worth) and 2 . Your end point in the subjective is only accurate to within o.25 anyway? On the other hand if the patient is younger and driving, I would take off the 0.25.

• nat // May 30, 2008 at 10:26 am

  Hi,
  Thanks for the response jane.

  Just a quick question on Low vision, if i dispensed a high add, so decided to use BI prism as well, i know this aids convergence, so does that mean the eye moves in? i thought eye moves towards apex of the prism??

• nyn // Jun 1, 2008 at 9:43 am

  Hi to all examiners, you gals and guys are doing a fantastic job!!!
  Like to say firstly, thank you for answering my last question, and secondly for hopefully answering my next 2 questions. Here goes…

  Question 1: BV
  We have recently changed our testing charts to electronic screens which are not polarised, thus dissociation is carried out by using coloured filters. I am finding when using fixation disparity on px’s presenting with large phoria’s and symptoms of decompensation, the px finds it very difficult to understand the test. It seems that the filters are not really dissociating the eyes, resulting in to many green, red and black lines.

  My question thus is, what other tests can I use to determine the level of compensation after I have prescribed prisms to help control the phoria. If that makes sense!!!

  Question 2: Toric CL
  Px has a Rx of -1.00/-4.00*180 R=L, and wants soft lens so I order the Freq XL Toric Extended Range: -1.00/ -3.25*180 R=L.

  My question is do I make any adjustments to the final sph power with the aim of improving vision, as 0.75D of astigmatism is not corrected in the above example. Is there a rule or an equation for the amount of extra sph I might add to correct for any amount of uncorrected astigmatism?

  Many thank nyn

• Jane Macnaughton // Jun 2, 2008 at 4:20 am

  Krissy,

  From Bill Harvey:

  2-non arteritic ION:
  Both arteritic and non-arteritic present as a shut down of supply of blood to the optic nerve head resulting in a sudden reported loss of vision. This loss is rarely total but is a sudden altitudinal loss affecting central vision. Both require emergency referral. The arteritic is due to inflammatory cells and, importantly, the risk to the other eye is much greater (some say as much as a 45% chance of loss in the next week!). It is related to a systemic vasculitis, such as GCA or others, and so the patient is often symptomatic relating to the systemic problem. They require a biopsy and a sedimentation test (ESR) to establish the inflammatory load and site of inflammation and intensive steroid intervention is needed. Non-arteritic AION is best thought of in the same way as an CRAO – calcific emboli blocking blood flow. It is therefore similarly emergency. The threat to the other eye is less but significant while these patients have a serious risk of embolic damage to the brain (stroke), heart and lung – all potentially fatal. Medical intervention is cardiovascular assessment to decide on the source of atheroma sloughing off the calcium (often the heart) and vessel treatments including surgery.
  3-Complicated PVD and retinal detachments:
  The clue here is the term ‘complicated’ as it implies a PVD resulting in retinal damage. The presence of Shafer’s sign is indicative of RPE damage and therefore treated as an emergency. A PVD may occur without retinal damage and often does (nearly all myopes eventually show one) but there is unlikely to be shafer’s nor persistence of the flashing. These you can monitor yourself as long as you take good notes and advise patient to report immediately any recurrence of symtoms. If in doubt refer according to the telephone advice from casualty.
  4- flashes and floaters.
  Tricky one this as always and related to a discretionary interpretation of risk factors and symptoms. With high myopes or any persistence of symptoms I would be minded to play safe at PQE level and offer a referral to clinic via GP for a full peripheral retinal check. Only if certain of PVD without retinal compromise (and the value of Shafer’s cannot be underestimated) might the latter option be suitable.
  5-pre retinal haems which can occur in diabetes: what is there exact location, (pre-retinal and sometimes under inner limiting membrane with a characteristic flat top or vitreal and spreading.. how do they disappear, and how long do they take to dissapear. Can vision still be adequate if pre-ret haem? Reabsorption may take weeks depending on extent and loss of vision is directly related to obscuration of the macula

• Peter Chapman // Jun 2, 2008 at 9:56 am

  Hi Krissy

  For the exam you will be expected to know

  1. What differential prism is and why it occurs
  2. Calculate the differential prism in a prescription
  3. Suggest solutions for differential prism and why they work

  So, here’s an example

  Prescription R +6.00 DS 6/6 add +2.00 N5
  L +4.00DS 6/5 add +2.00 N5

  So, the patient needs spectacles for DV and NV. There are 3 main options used in practice to correct this: separate pairs, bifocals or varifocals. However, we know that when a patient with anisometropia looks the near portion of multifocal lenses,
  differential prism at the near vision point is created and may not be tolerated. (An understanding of why this occurs needs to be known!)

  We know that the patient will suffer differential prism of 2∆ base up in the right eye. As this is generally more than can be tolerated, we should be prepared to correct it.

  There are roughly 8 possible individual solutions but these generally fall into three categories, single vision pairs, different sized segments and prism controlled bifocals.

  1. Single vision pairs – properly centred they give the best results as the eyes look through the optical centres of both lenses and so little prism is induced.

  2. Using different round segment sizes works as the larger the segment the more base down prism is produced (think about the shape/thickness of a round seg).

  A formula d1-d2 = 20 x vertical differential prism / reading add

  A round 25 segment produces less base down prism than a round 38 as the optical centre is farther away from the near visual point. The formula is used to calculate the difference in segment size needed. In this example the segments used would be a round 45 and a round 25 segment in the right and left lens respectively.

  3. There are many bifocals in which prism control can be created. Some use “slab off” techniques and some use cemented segments. When using “slab off” bifocals are used, the technique is done to one lens only and the least positive or most negative lens is “slabbed off”. A prism segment bifocal can has prism worked on the near portion in any direction. There is only one segment size which this can be applied to and that is a R30mm segment crown glass lens.

• Jane Macnaughton // Jun 2, 2008 at 10:31 am

  Nat –
  High Add: the eyes don’t move – the image does. The prism is doing the work for the patient. Base in.

• Krissy // Jun 2, 2008 at 10:54 am

  ahhh, thankyou! Thats brilliant..i think i have it all sorted now…ergence system would not be able to handle 2 BU as vertical FR’s are small!! i.e less than 1 dioptre can only be tolerated!

  Many thanks.

• nat // Jun 2, 2008 at 3:26 pm

  Jane,
  anay chance of you explaining how the prism actually works in this context? I always thought the eyes moved??

• Jane Macnaughton // Jun 3, 2008 at 12:47 am

  Nat: here goes:

  A prism simply alters the path of light.
  If you introduce a prism in front of an eye that is already fixating an object – the image of the object will appear to move – the eye then has to refixate in order to see the object again.

  In the case of the low vision device, the high reading addition has such a close working distance that the eye/s are unable to move/converge to fixate the object. The prism is introduced to move the image into the patient’s one of sight for them, so to speak.

• Fiona // Jun 5, 2008 at 6:01 am

  Hi.

  For the the routine examination will I have to do mallet unit test if CT reveals no movement, or minimal movement?

  When doing th reading add method explained above, is it ok to also offer the patient -0.25 when refining near add?

  If my px experiences diplopia on one position in motility testing, what do i do next in the exam situation? Will i have time to go on and test ductions? Is it ok to stop there and say you will call px back for a BV work up, or refer for hess screening?
  Kind regards,
  F.

• Simon Frackiewicz // Jun 5, 2008 at 1:03 pm

  Hi Fiona
  Personally, I would say it is superfluous to do the Mallett test in the absence of movement on covertest, however, if there are symptoms of asthenopia, it may pick up a tiny uncompensated vertical deviation which is hard to see on cover test, so don’t rule it out. Avoid correlating size of deviation with need to do the Mallett unit - a tiny deviaiton may be symptomatic and show slip whereas a large deviation may be well compensated, so the indication for doing the Mallett unit, in my opinion, should be the presence of symptoms.

  Re: diplopia on motility, it is good practise to do a cover test in all positions during motility, thereby effectively testing ductions and versions. If the diplopia is incidental, i.e. not the presenting symptom, it may be appropriate to say you will call back for BV work up. Ultimately, you need to choose how best to spend your time on your routine and do the tests which are appropriate to help you decide how to manage your patient.

  Re: reading add, I personally offer + and - 0.25 and give the add for which there is no improvement with either.
  Hope this helps.
  Simon

• Simon Frackiewicz // Jun 5, 2008 at 1:09 pm

  Hi Nyn,
  Sorry for the delay in replying. The problem with your screen does indeed sound like a mis-match between the colours of the filters and targets. My chart (Test Chart 2000) allows you to alter the colours to get the perfect match.
  Failing this, you can use Sheard’s or Percival’s criteria to calculate the optimum prism, by combining results from fusion range and angle of deviation. Alternatively, you can simply compare the subjective comfort of prisms by gradually increasing the power until there is no further increase in comfort, thereby giving the minimum amount necessary. Not very scientific I know, but better than nothing.
  Hope this helps
  Simon

• KR // Jun 9, 2008 at 8:18 am

  Hi quick question in regards to the routine exam.
  Some of my notes say if after ret, px is 6/6 or 6/5, dont waste time with subjective eg cross cyls, but during my quarterly assessment my assessor told me that i have to do subjective irrespective if the px’s va is 6/6 6/5, which is correct?
  Thanks

• FL // Jun 9, 2008 at 10:34 am

  Hi
  Quick question for ODA, in diabetic patients, is maculopathy treated with a ring pattern of laser, or can it be with a scatter pattern aswell, and again in proliferative DR is there a criteria in order to treat with a particular laser pattern?
  Thanks
  FL

• FL // Jun 9, 2008 at 10:42 am

  Hi, Another question, this time regarding iop measurement techniques, i believe the contact method, uses the concept that the amount of force needed to flatten a specific amount of the cornea, is propertional to the iop, whereas i don’t completely understand how the non contact method works?

• KR // Jun 9, 2008 at 11:19 am

  Also if patient has no field defect, optic disc appear normal, angles open, but on contact tonometry IOPs are 28mmHg, is the referral to the ophthalmologist urgent (within 2 weeks, or routine?
  thanks

• Sundeep // Jun 11, 2008 at 5:20 am

  Hi just a question on acute anterior uveitis. Why does a patient get a miotic pupil in uveitis and what is the mechanism behind this?

• Fiona // Jun 11, 2008 at 9:16 am

  where can i find the exact requirment for the required visual field to drive legally? is this standard to drive safely or is it a legal requirment?

• bry // Jun 11, 2008 at 12:57 pm

  fiona.
  I think the visual field req’s are in the AOP memebers handbook. It’s 120 degrees horizontal, with 20 degs above and 20 below the horizontal with no significant defect in this area (sig defect is 4 points clustered together missed). Members handbook is on college of optometrists website - members only area. This standard is only required/needed to be tested if a defect is suspected. If no defect is suspected, there is no statutory requirement to test/prove visual field. (My assessor was ultra-hot on law!!!)

• Jane Macnaughton // Jun 12, 2008 at 5:48 am

  Hi KR /Jun 9
  I would never remove the subjective despite end VA – a patient could easily be 6/5 with a -0.50 cyl that is 10 degrees off. The patient is likely to Non-tol if you don’t get the cyl axis where it really needs to be.
  In addition, you need to ensure you push maximum plus / minimum minus which you can’t be sure you have achieved unless to do a full subjective. For example, I may be (nearly) presbyopic but still capable of seeing 6/5 though an over-correction of -1.00D say.
  Please keep your full subjective in the Routine. Eyebrows would be raised if you skipped it..

• Jane Macnaughton // Jun 12, 2008 at 6:15 am

  FL / June 9
  Diabetes: to follow
  Non Contact tonometry: you may need to go through some old uni notes here.
  There are two basic methods – one method is measuring the time it takes to flatten the cornea, the piston pressure remains constant. The other is an increasing piston pressure cutting off at the point where the cornea is flattened.
  A light beam is directed on to the cornea and is reflected back into a receiver at the point when the cornea is flattened. This will tell the machine when to cut off the puff from the piston.

• Jane Macnaughton // Jun 12, 2008 at 11:20 am

  KR June 9
  Hi KR this is a classic CDM question. You need to consider your own personal referral criteria here and take into consideration local protocols and guidelines including the National Eyecare Pathway guidelines. For example, what do you consider is the upper limit of normal or wheb to refer on IOP alone?
  What is ocular hypertension and when would the local consultant consider prophylactic treatment?. 28mmHg is after all a little on the high side – what you don’t want to do is to wait until there is a vf defect – there a significant degree of nerve fibre damage occurs before a vf defect appears.

• Jane Macnaughton // Jun 12, 2008 at 12:10 pm

  Sundeep / Jun 11

  Mechanism of miosis in ant. uveitis: not straightforward! This site seems to give the best explanation.

• Jane Macnaughton // Jun 12, 2008 at 12:16 pm

  Fiona / Bry June 11
  Links for VF and Driving from the Royal College of Ophthalmologists.

• Fiona // Jun 13, 2008 at 2:43 pm

  thanks for that jane.

  Ive been revising like crazy past few weeks, but what i am revising is all the same stuff i revised for the quartley assesment competencies…i was just wondering is this enough? will the examiners go into more detail in the cdm and oda than what was asked in the quartley assesments which i thought were actually pretty thorough and intense. In you opinion what are harder to pass the quartley assesments or the finals?

• Fiona // Jun 13, 2008 at 2:46 pm

  is it possible to be asked about contact lens solutions and mode of action etc in the exams as the cl exam is only 5 min clarification right?

  also, in terms of fitting a keratoconic would it be adequate to say in a cdm exam that i would refer to a HES optom more experienced or must i know all about the different rgp lenses for keratoconus?

• ishi // Jun 15, 2008 at 1:40 pm

  Hi,
  I have a few questions wondering if anyone could help:

  1. Why does macular sparing occur if visual cortex lesion occurs i.e stroke on the field plot?
  2.if i saw this field plot on a px at what urgency would i refer?
  3. is the cherry red spot at macula in a artery occlusion due to the thin retina overlying the choroid at the macula?
  4. to dispense a 2 year old would it be adequate to use polycarb lenses as cr39 may harm the child if shattered? Will the nhs cover this? Or would we expect px to pay?
  5.if in cdm px hobbies is gardening, would you recomend safety glasses? what type?
  6.when using high adds, one way to incorporate the prism is by decentration. How else could you incorporate it in progs and SV lenses?
  7. if px told me he had high blood pressure and on beta blockers, and upon opthalmoscpy i notice CWS and haems..what degree of urgency do i refer and to whom? Is just gp sufficient for better control of meds? or ophthalmologist?
  8.whats the difference between herpes simplex and herpes zoster? herpes simplex lays dormant in trigeminal nerve and when activated causes dendritic ulcer right? what cause the activation? how does this differ to herpes zoster?
  9. in how much detail would i need to know about refractive surgery? for example if in cdm px’s history says he wants to have laser surgery and we dont offer it, what do i do? do i need to be able to explin the procedure? where do i tell him/her to go?
  10. before opthalmoscopy in routine exam would it be ok to use alcohol gel to disinfect hands or must i wash them in a sink? is it best to check with the examiner?

  Thankyou for any kind of help.

• Jane Macnaughton // Jun 16, 2008 at 12:50 pm

  Fiona (June 13)
  You need to look at the SfR as a whole; you have been developing your skills over a matter of months. The Core Competencies will in part create the skeleton upon which you must build your knowledge so given that the FA samples a number of the competencies that were covered in the QA, then yes, you will feel that there is repetition. But this is a good thing! We do not expect you to be learning anything new by the time you come to the FA – just practicing the skills that you already have.
  Regarding which are harder to pass – well, that’s very subjective and will differ between individuals.

• Jane Macnaughton // Jun 16, 2008 at 12:58 pm

  Fiona (June 13)

  CL solutions – you will have covered this in your QA visits. However, you will be expected to give advice about solutions etc to the patient in the aftercare (where relevant) so the examiners may be listening to what you have to say. Those end of exam ‘clarification questions’ are not like a viva; they are there to serve as an opportunity, for example, for the Examiner to double check something that the candidate said, or ask them to print out something that is illegible on a record card. Nothing major. They are not likely to be Pass/Fail questions.

  It is unlikely that you will be asked detailed questions regarding CL fitting in the CDM exam. However, in an exam situation where you are asked about KC fitting you should have a basic idea of how these lenses are fitted but no, you would not be expected to know the detail and certainly not about allof the fitting sets currently available. However, be cautious about discussing the need to refer any patients (KC or otherwise) onto more experienced practitioners. Make sure you are sensible and have covered all bases first as you don’t want to use it as your get out clause – many candidates use that one all too easily – even if it is the right sort of answer the examiner expects to hear.  After all – how would you gain the experience yourself.

• Jane Macnaughton // Jun 17, 2008 at 12:37 am

  Ishi (June 15)

  Thank you for your questions. As there are quite a few that are purely academic rather than exam based, I would rather point you in the direction of a book or two or a webpage perhaps?

  1. Macular sparing: this is all to do with the degree of cortical representation. Try this: http://www.indiana.edu/~pietsch/hemianopsia.html
  2. Macular sparing is not a ‘field plot’ – it’s a lack of it. Like all vf plots – think about he underling cause, the length of time the lesion has existed and base your referral criteria upon that. However, remember at a significant amount of nf damage must occur before a vf plot exists, so something significant is likely to be the underlying cause (tumour, vascular accident etc)
  3. Macula nourished by unaffected choriocapillaris in this case.
  4. Doubt CR39 will shatter – still one of the best options for children. Think also about the small eye size which will also reduce tendency to break.
  5. Gardening: http://www.rnib.org.uk/xpedio/groups/public/documents/publicWebsite/public_protectingeyes.hcsp
  7. If asked this is an exam you need to have more detail. Location of the haems for example – this will have a bearing upon the degree of urgency of your referral – ie if the macula is involved. Ideally this many needs to been seen by both but the most important thing here is to get his BP under control.
  8. All about herpes: I would rather refer you back to a basic ophthalmology text book for this one as this is purely and academic question. This text book is highly recommended and this web site also.
  9. I would say that detailed knowledge of refractive surgery procedures is not high up on you study list. Be aware of its existence, basic knowledge but more importantly you need to know be able to recognise it and know what you would do if you come across complications. Referral on for Refractive surgery really isn’t a tall priority and not within your remit. It certainly won’t hold a pass/fail criteria unless you see complications.
  10. Wash your hands before the exam. That is enough. No need to disrupt the beginning of the exam with a sharp exit to the sink or otherwise. If however you sneeze into them in the middle of the exam then you should ask to leave to room to wash again!

• FAR // Jun 20, 2008 at 10:09 am

  WHAT TYPE OF LICENSE DO BLACK CAB DRIVERS HOLD?CLASS I OR CLASS II?AS THEY ARE PCV?

• trisha // Jun 20, 2008 at 2:46 pm

  Hi, I am a bit confused about prismatic effect for oblique cyls. What would be the prismatic effect for the Rx
  R:-2.00/-4.00×45.
  I think you’re supposed to take 2/3 of the power according to the formaula, but which power do you use?
  Also if the rx in the LE was
  LE:-0.50/-0.50×90
  what would the differential prism be? We had this in a cdm in a mock course but I didnt get the whole answer.

• tanya // Jun 21, 2008 at 3:48 am

  Hi, in the final routine exam whereabouts on the college record sheet do i write the result of the OMB tests/motility/pupils/npc etc?? i.e. what box am i supposed to write these finding in. thank u

• tanya // Jun 21, 2008 at 3:59 am

  One more question, what are the referral guidelines for 3rd/4th/6th nerve palsies?? i have always thought urgent. what does urgent mean?? within a few days or weeks?

• nirisha // Jun 21, 2008 at 11:18 am

  hi i have quite a few questions

  1. how soondo you refer an acquired horners? or any pupil defect?

  2. how soon do u refer an acquired nystagmus?

  3. what causes ectopia fovea?

  4. if a patient presents with a RSOT, and you cyclo them, do they still exhibit they RSOT or are they straight?

  5. when people have a suppression or suppression scotoma, is it only at one distance eg distance or near or can it be at both?

  6. in myasthenia gravis i understand patients need anitcholinesterases, so why are they given atropine which is an antimuscarinic?

  7. when someone has a microtropia, u can check by doing the 4 BO prism test. i was under the impression that putting the prism in from of the normal eye would cause it to deviate, but also the microtropic eye would aslo deviate through herrings law but not make the correcting movement. having read through kanski i get the impression that the microtropic eye would make no movement? is this the case or have i just misunderstood kanski?

  thank you!!

• nirisha // Jun 21, 2008 at 11:53 am

  also in the routine exam when diong retinoscopy, do we need to keep checking the eye that we are not doing to make sure we have an against movement? or is it sufficient to have checked it once and then leave it?

  also i prefer to do ret while standing up,is that ok for the exam?

  i am also aware that if in contact lenses you fail to wash your hands before carrying out slit lamp examination as this si unsafe, but why is it ok in routine to do ophthalmoscopy and touch the patients lids on lower gaze and not wash your hands?

• rb // Jun 22, 2008 at 1:13 am

  Hi

  DUring the contact lens exam we are required to narrate our slit lamp routine…is that also tru 4 routine? show i bring my own soft lenses in or are they provided?

  and during the ODA station (VOLK) is an examiner observing through a teachin arm?

• Peter Chapman // Jun 25, 2008 at 6:08 am

  FAR (June 20th) Black cab drivers are classed as passenger hire vehicles. Drivers need to have a standard car licence, pass a group 2 drivers medical, and pass a DSA taxi driving test. A private hire vehicle driver does not have to do the DSA test but must have 3 years experience.

  Black Cabs: http://www.hmrc.gov.uk/bens/ben25.htm#b

• Jane Macnaughton // Jun 25, 2008 at 6:10 am

  tanya // (Jun 21)
  Those OMB tests that come before the subjective tend to be placed in the Ocular Examination box – those test that you would typically so after the subjective will go into the Subjective and associated Findings box. Initially the College did consider givign you a blank sheet. However we decided upon a slightly structured page instead. As longas the detail is placed somewhere that is sensible 0 most would be happy with that. Best you keep in some semblance of order so that the examiner can follow it or refer to it quickly.

• Peter Chapman // Jun 25, 2008 at 6:10 am

  Tanya (21st June) I use these referral categories: emergency/immediately sight threatening – same day. Urgent –within a week. Soon – within 1 month routine – within 3 months.

• Peter Chapman // Jun 25, 2008 at 6:11 am

  Nirisha (21st June 2008) right… here goes:
  a) acquired Horner’s – needs urgent investigation to work the position of the sympathetic nervous system defect. It could be caused by an internal carotid artery dissection.
  b) I would refer acquired nystagmus fairly promptly to a neuro ophthalmologist.
  c) Ectopia fovea is an unusual position of the fovea in relation to the optic nerve. It is associated with retinal pathology such as chorioretinitis, fribrous bands, coloboma’s. Follow this link to a research paper: http://www.ncbi.nlm.nih.gov/pubmed/1594198
  d)
  e)
  f) Myasthenia – Atropine is only used intravenously during the diagnostic phase of the edroponium test. This has potentially life threatening side effects in a small number of cases and by giving atropine the muscarinic side effects are minimalised.
  g) Microtropia – with the prism in front of the non stabismic eye, both eyes will make the initial version movement, but only the non strabismic eye will make the second vergence movement. With the prism infront of the strabismic eye, nothing will happen.
  h) Retinoscopy – check for against movement at the start. It never hurts to check again if possible. Do ret standing if you prefer, however, the most important things to remember are your working distance and horizontal and vertical alignment to ensure you are not “retting” of axis.
  i) You must wash your hands in the cl exam. I do not believe it is a fail criteria in the routine exam but it never hurts to impress the examiner.

• Peter Chapman // Jun 25, 2008 at 6:13 am

  rb (22nd June). You may well be asked to narrate your slit lamp exam, explaining what beam you are using, what you are looking for and any filters you use. You do not need to provide soft Cl’s, the exam centre will provide diagnostic lenses, but you DO need to provide the RGP lenses. As for the ODA exam, there may be a teaching arm or the slit lamp may be attached to a video screen. Some examiners use other clues like the position of the Volk lens as to whether you are performing the technique correctly. You should be competent with a Volk lens on a dilated pupil by now!

• Jane Macnaughton // Jun 25, 2008 at 6:30 am

  We hope that you have found this thread useful. We shall be collating the information for FAQs for future candidates. As the exams are now upon us, the thread is now closed. We shall update the outstanding questions as soon as we can over the coming days.
  Good Luck to you all!