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It’s been a few years since I sat my OSCES, although the trauma is still fresh (only kidding).  I’m now in a position where I’m assessing students, not as a College examiner but as part of my teaching commitment at uni.  

The first thing I wanted to say was: I get as nervous about assessments as the students I’m assessing.  I was telling a colleague who is an actual College examiner (and all-round nice person) about this and they said that they feel the same way.  So just remember, when you walk into that OSCE station, the examiner is hoping to give you good marks.  They want you to succeed.  It’s painful to watch someone struggle, especially if you know that it’s down to nerves rather than a lack of knowledge or ability.

So, here’s my top five OSCE preparation tips:

1. try to get as much OSCE practise as possible.  Go to OSCE preparation courses and take turns testing and timing your friends doing ret or history and symptoms.  I was lucky enough to attend a full blown (16 stations) OSCE preparation course run by NHS Education Scotland in addition to the OSCE course (which I think was around 10 stations) that the company I was working for had arranged for us.

2. identify any areas where you need to improve.  This is quite difficult and requires you to honestly think about your skills and knowledge.  Of course, we all like practising the stuff we are good at and try to put off doing things we are unsure about.  Sit down with the College competency lists for Stage 1 and 2 and look through them point by point, highlighting any areas you think you need to work on.  Also, avoid the temptation to just “work on everything”, because you’ll end up spending a long time going over things you are actually good at.  Get your supervisor involved as well – ask them what they feel you might need to improve upon and press them if they say “nothing”.  There’s always something you could be doing better.

3. don’t personalise failure.  If you are struggling with something, it doesn’t mean you are/will be a bad optom.  It might be that you haven’t had much experience in that area.  If you are really unsure of something then don’t be afraid to talk to your colleagues, friends or supervisor about it.  You are learning just now so it’s the perfect time to ask questions.

4. try to visualise the OSCEs.  This is something that you might laugh at but I honestly think that sitting down, closing your eyes and visualising what it is going to be like is a great way of controlling your nerves.

Imagine standing outside the first cubicle, reading the scenario on the door, it’s something you are familiar with and you feel confident, after the minute is up, you open the door and stride in, confidently.  The station goes well and you move onto the next…

It’s like tricking your brain into having a positive memory of something that hasn’t yet happened.  I think a lot of nervousness comes from the fact that you are in an unknown situation and that’s why my first tip was to try and experience OSCE-type exams as many times as you can before the “real” one.

5. engage brain before opening mouth.  This is something I do all the time – I start talking before actually considering what I’m going to say.  It’s especially bad when you have a time crunch.

When you are in the OSCE station and you know that time is ticking away, you feel you need to start NOW. Right now. Just start talking. Five minutes isn’t a long time.  And the silence is awkward.  Say something, that’ll relax you.  Just start talking. You can always work out what you are going to say on the fly. 

I’m here to say: resist that urge and take a few moments to breath and consider what you are going to say.  Think of this as investing 10-30 seconds on getting it right the first time.  Also, make this a habit that you carry into practice with you.  Real world patients are far less forgiving when you say something and have to completely backtrack than your OSCE actors.  Ten seconds and a deep breath are probably one of the best pieces of advice I can give you, regardless of your situation.

So those are my general OSCE tips.  If you are new to this blog, you can go all the way back to May 2014 and read my own OSCE journey (Mock OSCEs, More mocks, NES Mock OSCEs and The OSCEs)

I’m hoping to get a podcast up and running in the next month or two which will focus on student, pre-reg and NQ experiences so watch out for that. 

Finally, check out my communication based card game “Deal With It” which can be used for OSCE preparation and revision for individuals or groups (as featured in Dispensing Optics and Optician magazine!): Deal With It



I can’t believe that it’s been four years since I started this blog.  

Looking back, pre-reg was just the beginning of the journey.  The amount of learning that takes place each day in practice is amazing – every patient and every eye has a different story.  Even the most routine of eye examinations can turn into something else.

This December was unusually busy in our practice.  When people want an eye test on New Year’s Eve, you have to wonder.  Anyway, I had a full clinic but it was mostly plano children so I was flying through the appointments.  At one point, after testing a family of four kids who couldn’t even muster +0.50DS between them, I was 45 minutes ahead of the diary.  Just then, a man in his fifties came in looking for an appointment.  He had already been turned away from a couple of other opticians although one of them had, helpfully, advised him he really should see someone today.

I was in my test room and heard him giving the details to one of my colleagues.  He hadn’t had an eye test for years, didn’t need glasses, vision was fine except yesterday afternoon, he noticed that he couldn’t see anything at the bottom of his left eye.  There was also a little red dot on his left sclera.  He thought it was an eye infection.

The optical consultant knew straight away that this was an emergency and there just happened to be the perfect sized slot in the diary.  After he was booked in, we did fields, photos and pressures.  Pressures were normal, the photo looked generally okay except for some nipping and copper wiring of the retinal blood vessels.  The fields showed a complete loss of sensitivity in the lower hemifield of the left eye.  I immediately suspected a central retinal artery occlusion.

When he came into the room, he told me that he’d never had any issues with his eyes and said, “It’s just an eye infection, isn’t it?”

Looking at the field plot, I told him that I suspected it was a problem with one of the major blood vessels in the eye.  I explained that I was going to check his vision and have a good look at the back of his eyes but, given his symptoms, I would want an ophthalmologist to see him today.  I think this shocked him.  I wonder if I gave him too much information before we’d even sat down in the room but I was aware of the timescale.  A CRAO is treatable in the first 24 hours and he had first noticed the issue the afternoon before so we were coming up to the end of the 24 hour window fast.

History and symptoms were unremarkable, except for the fact the patient hadn’t ever had his blood pressure or cholesterol tested.  I checked his vision and it was 6/7.5 in the right eye and 6/38 in the left.  He reported he couldn’t see the lower half of the chart with the right eye covered, as expected.  Pupils showed a left RAPD.  I assume this was new, given the symptoms described.

I then dilated him and, while the drops took effect, refracted him.  VAs ended up at R 6/5 N4 and L 6/38 N12, no increase with pinhole.  He had a very small prescription, a little bit myopic, which helped with his reading.

On Volk, I couldn’t see any emboli in the central retinal artery, although the vessels were twisted around each other when exiting the disc.  The retina itself looked pink and healthy both superiorly and inferiorly.  I explained to the patient that I couldn’t see any blockages in the arteries but, given the signs and symptoms, I did believe there was an embolus blocking blood flow to his superior retina.  I was going to call the hospital and ask if the ophthalmologist would be able to see him that day.

As the patient waited outside, I phoned the on-call ophthalmologist and gave her a run down of the situation.  She was surprised at his VA, expecting hand movements, and asked about how long it had been since onset.  I could only give a vague estimate – the patient was at work and had noticed the issue but hadn’t noted the time (why would he, really? He thought it was an eye infection, not an episode of 24).  She asked me to send him up to the hospital straight away so I gave him a referral letter and his daughter agreed to drive him to the eye clinic.

I was a bit annoyed that such a time sensitive issue was passed from practice to practice.  In our store, we have a policy of calling other opticians in the area until an appropriate appointment is found for a patient presenting with pain or loss of vision.  If all else fails, we advise patients to go to A&E.

I think we’re getting the healthcare/retail business balance wrong – patients with high prescriptions and a taste for designer frames are slotted into clinics routinely while those with a problem (and, therefore, no dispense at the end) may be turned away by optical assistants and managers with the excuse that they are “fully booked”.

As you may remember, I started the Independent Prescribing course all the way back in 2015.  At the time, I was working in a multiple, I had the opportunity* and thought that being an IP optom was a natural progression for me.  I loved the idea of being able to provide treatment for my patients with straight-forward eye problems without sending them to their GP or the hospital.  Sometimes, I would ask a GP to prescribe something only to end up playing phone-tag with them over the details.  When I worked in Lanarkshire, I became LENS qualified – this allowed me to supply chloramphenicol, fusidic acid, hypromellose, cyclopentolate, aciclovir (later, when they had problems sourcing that, it was replaced with ganciclovir) and other preparations for minor eye-related ailments.  I thought this was a wonderful system and really missed it when I left that health board to work closer to home.

You might be wondering why, two years down the line, I’ve only got one module (out of three) under my belt.  Well, in 2015, I couldn’t get the time off work to attend the second module and then, I re-registered in 2016, only to find out that I’d booked a holiday (for a special birthday) at the same time as the module exam**.  Ooops.

So, here I am, in 2017, two years after starting the course and I’m just over half-way through the process.  The exam for module two was on Friday and this weekend we had a selection of lectures and tutorials.

For anyone thinking about the IP course, it’s a bit of a strange experience.  Instead of having a weekly class, the teaching happens in three short bursts, followed by a couple of months of self-study.  Each module has coursework and then an exam at the end of it.  The first module concentrates on common anterior eye complaints, the second is focused on glaucoma and the third is mainly about systemic drug interactions and adverse drug reactions.  The course work is a case report (for module 3, it’s two case reports) and each exam is a three hour affair which includes multiple choice, short answer questions and a VRICS style section.

While the material is quite straight-forward, in the beginning, it can feel overwhelming.  Once you realise that, as IP optoms, there are only a few types of drugs we will be using, it becomes much simpler.  If you have a BNF, a quick look at Section 11 (the eye bit) will show you every drug and preparation that you might possibly use, excluding the intra-ocular drugs (although I’m all for continued professional development, I think I’ll leave the Lucentis injections to the ophthalmologists and ophthalmic nurses).

Overall, it’s been an interesting experience and I would urge anyone thinking of getting IP qualified to do it sooner rather than later.  When I was a pre-reg, I was advised by a wonderful locum optom to do the IP course as soon as I could – she said, the longer you are qualified and out of the habit of studying, the harder it is to get back into the swing of it.  This is especially true for the IP course where, as well as working, you will have to do a lot of independent study: revising for the exam, preparing the coursework and reading articles on such diverse (and sometimes desperately boring) areas such as pain management, clinical governance, laboratory investigations and anti-microbial agents.

So, fingers crossed that I have passed the second module.  Still, I have another two pieces of coursework, the module 3 exam, twelve days of hospital experience and the final College of Optometrists exam to sit before they let me loose with a prescription pad.


* NHS Education Scotland sponsors optoms based in Scotland, which is yet another reason I’m lucky to be practising here.

** As the course happens around the same time every year, this week I spent my birthday studying for/panicking about the exam the next day.

I thought I would write a post on what I do in practice and why.  This started out as a quick post but has turned into a bit of a monster so I’ll separate it into a few parts.  This post deals with the first part of the eye test, up to refraction.  The next part will be on refraction and the final part on the health check and management.

So, without any further ado, my routine:

Each working day, I arrive at my practice with some time to spare.  I usually get there 15 minutes early to set everything up – this involves little things like switching on the computer, test chart and slit lamp console.  While the computer is booting up or logging in, I lay out all the things I’ll need.

Chef’s have a thing called mis en place, which is having all ingredients prepared before service.  It’s what happens in Jamie Oliver’s TV kitchen before the cameras are turned on: every ingredient is peeled, chopped, weighed and set out in a logical and accessible place before the cooking begins.  Like chefs, we have time limits.  No-one wants to wait an hour for their meal because the chef has to hunt high and low for each ingredient and no sane patient would leap at the chance of spending double the time in the test room because their optom was inefficient.

So here’s my optom version of mis en place:

I lay out my occluder, budgie stick, +/-0.25DS flippers, lens cloth (very important in my practice as the cyls don’t have handles so are always covered in fingerprints), pen torch, pen, spare pen (for when the first one stops working or a patient/staff member* steals first pen), confrontation stick and my cross cyls.  I’ll unpack my ret and ophthalmoscope and have them handy as well.  If there are children in the clinic, I’ll put the Titmus and Ishihara within reach and if someone is attending for contact tonometry and pachymetry, I’ll have both the Perkins and Accupen in my room before the start of the day.  I also make sure I have an Amsler handy and that there are enough leaflets on common conditions in my room.

On the slit lamp table, I put my Volk lenses, Wratten filter, cotton buds and the little box I keep Sterets and needles in.

Before my first patient, I’ll make sure the slit lamp isn’t on some weird setting (like 40x mag, tiny spot and green light) and go through the computerised test chart to make sure when I hit the xcyl button, it gives me dots instead of circles (weird, I know, but I prefer the dots).  We also have one of those test charts where, if you press the wrong button on the fixation setting, you end up with a terrifying clown face so I make sure that it’s on the green dot not Pennywise.

By taking a few minutes to set everything up, I’m saving myself time during the day.

The patient will be pre-screened by the optical consultants.  In my practice, they usually do a mini history and symptoms and write any concerns on the front of the record card.  They also ask about work, hobbies, driving and VDU use.  After that little interview, the patient is then autorefracted and has non-contact tonometry done.  They then complete a 24-2 screening test on the Humphrey.  It’s good to have the autorefractor result before fields because you can then choose an appropriate lens for the visual field test.

After the 24-2, the optical consultant takes a fundus photo.  I will have a moment to check the photo on my screen before the patient is brought in.  I find checking the photo before the test helpful because I do fundoscopy after refraction and if the patient is struggling with refraction, there’s a good chance I have an idea why, based on the photo.

When the patient comes in, I introduce myself and ask how they are today.  We have a bit of a chat and I tell them they can pop their bags down on the chair over there then I ask them to have a seat “in the big chair”.  If the patient is unsteady on their feet or using a cane, I’ll make sure I flip the footrest up on the chair, allowing them to get closer to the seat before sitting down, and once they are comfortable, I’ll put the footrest down.  I also like to make sure I’m close by while they are sitting down, to provide a hand if they are struggling.  I usually say something like, “I’m just here if you need a hand or something sturdy to hold onto”.

Once we are both settled, I start history and symptoms.  If they come in with a problem, I’ll go straight to that.  If they have a sore eye or a red eye, I’ll just start with, “So, what’s happened?” and the patient will usually launch into a pretty detailed account of their sore or red eye.  When they are finished, I’ll ask any other questions I need to, again, leaving the patient plenty of time to answer.

Assuming a routine eye test, after confirming their details and their reason for visit, driving etc, my usual history and symptoms goes something like this:

Do you remember your last eye test?

Do you wear glasses at the moment? What are they for? How do you feel your vision is with them? Any situations where you feel you aren’t seeing as well as you should?

Have you had to go to the hospital or GP for any eye problems? Do you ever get flashing lights in your vision? How about floaters – wee black dots or wee black wiggly lines? Do you ever get double vision?

How’s your health at the moment? Are you diabetic? Any high blood pressure? Do you suffer from headaches?

Are you taking any medicines at the moment?

Anyone in the family with eye problems that you know about? Anyone in the family diabetic?

I will then put the chart on and ask the patient, while wearing their current correction, to occlude their left eye.  I’ll hand them the occluder and 9 times out of ten they will cover the right eye and, by right, I mean left.  Ten percent of the time, they’ll cover their right eye, which is the wrong eye instead of the right eye which is the left**.  Sometimes they’ll close one eye and cover the other.  Sometimes they’ll try and wedge the occluder under their glasses.  Sometimes they won’t even use the occluder and instead cover their left eye with one hand while holding the occluder in the other.

Hopefully, at this point, they will have one eye covered and the other open.  At this point, I’ll ask them “what’s the smallest line you can read on the chart?” Eight times out of ten, they will pick a line and read it more or less correctly*** and I’ll then ask them if anything is standing out on the line underneath****.  Those two patients out of ten will do a number of things: read the whole chart from top to bottom, say random letters (maybe throw in some numbers and stars) that bare no resemblance to any line on your chart, read the line backwards or just stare at the chart for an uncomfortable amount of time before saying, “Oh, do you want me to read it out loud?”

This is repeated for the other eye and you now have an idea of how well your patient is seeing with their current correction.  I know at uni they teach you to check vision rather than VA with current Rx but there’s really no point doing that in practice – you want to know if you are improving your patient’s vision with your refraction and, let’s face it, writing down 6/60 and 6/120 doesn’t really tell you much other than your patient needs glasses.  Also, if your patient is 6/5 with their current prescription, don’t give them more minus unless it’s getting them to 6/4, 6/3 or giving them the ability to see through time itself.

After that, I’ll ask the patient to take their glasses off and give them a target to look at for cover test.

I will start with alternating cover test at distance then get the patient to look at an appropriate target on the budgie stick and do cover test at near as well.  If they report having problems with their vision while on the computer, I’ll ask how far the computer is and I’ll do cover test at that distance as well.

I’ve had a few young girls recently attending with no prescription (6/5 N4 unaided) but complaining of headaches when on their phone/tablet/computer – these girls all had large XOPs at near.  A few weeks ago, I saw a patient with a very noticeable cyclophoria which was so cool and unexpected that I may have spent a few minutes just covering and uncovering her eyes, thinking “Wow”.

Anyway, next I do cover/uncover, looking for tropias.

Then I tell the patient that I’m going to dim the lights (which I do) and I test pupils.  During each test, I tell the patient what the test is for, what I’m seeing and reassuring them that the result is normal (unless it’s not, then I come back to that later).  After testing direct and consensual reflexes (three times in each eye, exerting the pupil muscles enough that if there’s an abnormality, you’ll see it after three repetitions) I move onto the swinging flashlight test.  Pupil reflexes are a bit of an art and I was worried that I would miss an RAPD but, believe me, if you are watching closely and doing the swinging flashlight test properly, you won’t miss one.

I then pop the lights back on and we move onto motility.  I always sit for motility although there’s a bit of a debate about this.  This is the part of the test where the patient is likely to start laughing.  I don’t know why, maybe it’s something about the test or maybe my look of intense concentration is hilarious, but I’ve had eighty year old men in stitches during motility.

Next is confrontation, which always involves a bit of mental agility on the part of both myself and the patient because you have to cover the contralateral eye to them to test their field in that eye.  Strangely, this isn’t as much fun for patients as motility.

So, that’s the first bit of the eye test, with a bit of an observational comedy thrown in for you.  I’ll post the next part (refraction) in a little while.


* You know how you are.

** Isn’t English a wonderfully clear language.

*** There is a special place in hell for those who read the whole chart using the phonetic alphabet… Oscar… Mike… Foxtrot… Golf…

**** You should always push your patients to read a little bit more because some people are quite cautious and need an extra nudge to actually admit they can see a bit better.  If we just left it up to the patients to pick a line, their VAs would be all over the place.

Those of you who’ve been reading my blog will know I’m passionate about communication. Over almost four years and in more than 100 posts, I’ve told you stories about my patients, my practise and my journey to become an optometrist.  I’ve spent a lot of time thinking about communication and reflecting on how we approach new situations.  I’ve come to realise that the worst part of our job is the unknown.  Of course, we all become more confident as we gain experience yet, at the same time, there are hundreds of scenarios that we don’t know how we’ll handle until they happen.  Not only that, we don’t know how the team around us will handle those situations either.

In the last few months, I’ve developed a card game to help optical professionals and those in the process of qualifying hone their communication skills by asking them to imagine themselves in challenging situations.  It’s called Deal with it.

I’ve been really lucky to have met a wonderful optometrist and business person, Sarah, who has helped make my vision a reality.

Here’s a look at the box:


The cards have been designed to challenge players to adapt their communication style to fit the needs of patients with a variety of complex needs and conditions.

The game can be played in groups (for example, as a staff training exercise) or individually (to self test).  When played in groups, discussion and feedback become part of the game, making it a perfect training and team-building exercise for professionals working together in practice.  It can also be used as OSCE preparation or revision.

Each pack contains 56 cards: 1 suggestions card, 50 scenario cards and 5 action cards.  Each scenario card has two different conditions to explore: this generates a total of 500 possible scenario / condition / action combinations so there is plenty of scope for repeat play without repetition.  The action cards have communication tasks on them that cover the entire patient journey.  Games can last minutes or hours, depending on the number of scenario cards used.

If you want to buy a deck of cards or just to learn more, you can visit my website:

This post is yet another that got stuck in the “drafts” folder. It was actually written during my pre-reg and has since languished on WordPress in a half-finished state.  Today, I’ve bitten the bullet and finished it.

One of my patients today was profoundly deaf.  Now, I went to a sign language class last year and I picked up the basics (as well as colours, animals and weather… strange but true) but I still feel a little nervous about practising on someone who can sign properly.  I feel it will be like going to France and speaking French to a native for the first time, probably with a terrible accent and a lot of grammatical errors.  I once told my Russian teacher, during an oral exam, that I had problems picking up what he was saying because I couldn’t “see his mushrooms” (I meant “lips” but, well, griby and guby got mixed up somewhere between my brain and my mushrooms).

Before we get to the actual test, we should talk about what happened before it.  Making an appointment was difficult for my patient, who we’ll call J.  She’d received her recall letter and was given three options to book an appointment: 1) call us, 2) go on-line or 3) come into the store.  Now, J said the easiest way of booking was to come into the practice because using the telephone system was difficult (not impossible, you can get text phones) and the on-line system at that time worked by the patient requesting an appointment and then us calling them back (yes, facepalm).  Things have improved with this multiple – you can now book on-line properly, without having to speak to another human being.

So, J popped in with her partner (who was also profoundly deaf) and arranged her appointment.  She had a mobile phone and requested that we text instead of calling to remind her about her appointment (we would call everyone the day before to confirm) and to also advise her when her specs were ready to collect.

When J arrived for her appointment, one of the optical consultants (R, my work wife at the time) panicked a little about doing the prescreen.  She was unsure about how to adapt her routine.  Seeing her panic, I advised her how I would do it: instruct the patient while her glasses were on, tell her what the test did and how we wanted her to respond and, when the test was finished, we would tap her on the shoulder to let her know it was finished and then we would do the same again for the other eye.  Seeing that the OC was still unsure, I asked if she’d be more comfortable if I did the prescreen while she watched but she said that she felt a bit more confident and would give it a go.  I stood to the side, within the OC’s eye line so I could nip across if she had any problems but the prescreen went well and both the OC and the patient seemed quite pleased.  The visual field test was the challenging bit as we do the screening test that uses multiple points then ask the patient how many they’ve seen before we manually move onto the next presentation.  My patient and the OC worked out a system where the patient would hold up the number of fingers that corresponded to the points she’d seen and if correct, the OC would move onto the next one.  It worked really well and meant that the patient didn’t have to keep coming out of the correct position – she just stayed with her chin on the rest and forehead against the bar and held her hand up to show the OC after each part of the test.  When the OC showed my patient over to my room, they were laughing because she’d said that she had to be careful which fingers she held up for to say “one” and “two”.

There’s only one golden rule for patients with hearing difficulties: ask them how they want to communicate.  If they lip read: make sure you don’t shout (this distorts your lips) and that they can see your face clearly (keep their specs on as much as possible if they have high Rxs and don’t do Hx & Sx while looking down at your clipboard or towards your VDU).  If they are “hard of hearing”, again, don’t shout, just try to speak a bit clearer and louder and again, make sure the patient can see your face.  Some patients will ask you to shout, I try to avoid this because it wrecks my voice – instead, I use my public speaking training* and speak from my diaphragm rather than my throat (weirdly, this also makes you sound more confident so win-win**).

The eye test itself was unremarkable and, at the end, when J came out of the test room, her partner came over and signed, “Do you need reading specs?”  and I signed, “Too young for reading specs” which got a laugh.

He said he had two pairs of specs and was getting fed up of changing between them.  I signed that he needed… um, v…a…r…i…f…o…c…a…l….s.  My fingerspelling isn’t that great, you can probably tell.

In the end, it was a good experience for both me and my OC.  And I was relaxed enough to try out my BSL in a real life situation***.


* Sadly, I used to compete in debating and public speaking competitions when I was at school.  Without bragging, I wasn’t completely awful at it.

** Honestly, Google it.

*** I didn’t/don’t tell people I can sign a little because I’m terrified of being in a situation where I need to be able to sign better than I can – which, of course, puts me in a catch 22 situation where I want to get better at it but I’m afraid to practise it in case I insult someone’s ancestors by mistake.

Of course, as part of my PhD, I’ve been doing a lot of reading about glaucoma and visual field loss.  I’m still working in practice at the weekends and I find my approach to managing patients has changed based on the papers I’ve read.

I know not everyone has a spare three four months to read up on the latest research in glaucoma so I’ve chosen five interesting facts that may help my fellow optoms, pre-regs and students with their decision making.  For those who want to read more, I’ve added references*.

1) Early glaucoma affects central vision.  Usually we think of glaucoma as a disease that causes loss of peripheral vision.  Most example field plots will show a baring of the blind spot, arcuate defects and nasal steps but only the most severe will show macular involvement.  There’s actually a reason for this – we’ve been using the wrong test.

In practice, the standard field test we use is a 24-2 which covers the central 48 degrees with a 6 degree spacing between the test points.  Only four of the points tested fall within the macular region (central 8 degrees) .  If you can imagine, the little fixation spot the patient is looking at is located at 0 degrees, then the four points checked by the 24-2 are all just over 4 degrees from fixation.  Here’s a napkin drawing to help you visualise (and to show off my mad geometry skills):


Considering 30% of all retinal ganglion cells originate from the macula, it makes sense that this area is affected by glaucoma, a disease that causes ganglion cell death.  Several papers have been published recently showing that, despite previous wisdom that the macula was only affected in severe, end stage glaucoma, it can actually be one of the first areas affected.  Using a 10-2 visual field pattern may pick up macular defects that are too small or not in the correct location to be detected by the 24-2 pattern.  The 10-2 test covers the central 20 degrees (10 degrees either side of fixation) with a 2 degree spacing between test points.

Optical coherence tomography (OCT) shows thinning of the retinal nerve fibre layer (RNFL) in glaucoma.  Usually, if you suspected glaucoma, you would check the disc scan but, again, the macula with its abundance of ganglion cells is a better place to look for thinning.

Further reading: Grillo L. M., Wang D. L., Ramachandran R., Ehrlich A. C., De Moraes C. G., Ritch R. & Hood D. C. The 24-2 Visual Field Test Misses Central Macular Damage Confirmed by the 10-2 Visual Field Test and Optical Coherence Tomography. Translational Vision Science & Technology, 2016, 5(2): 15.


2) Certain areas of the disc are more likely to be damaged first.  As clinicians, we all know the ISNT rule and anyone lucky enough to have an OCT at their disposal will see that there is a “double hump” in the retinal nerve fibre layer profile around the disc.  The two humps are the inferior and superior regions of the disc:


Anyway, these two humps (the thickest parts of the optic nerve head) are the most prone to damage.  Any lady with a large chest will confirm this**.

If you think the optic disc of a right eye in terms of a clock face (superior is 12 o’clock, inferior 9 o’clock, nasal 6 o’clock and temporal 9 o’clock) then the areas corresponding to 6, 7, 11 and 12 on the clock are the most likely to be damaged by glaucoma.  For a left eye, it would be 5, 6, 12 and 1.  Interestingly enough, disc haemorrhages are usually seen in the inferior temporal portion of the disc (around 7 o’clock in right eyes and 5 o’clock in left eyes).

Further reading: Hood, D. C. Improving our understanding, and detection, of glaucomatous damage: an approach based upon optical coherence tomography (OCT). Progress in Retinal and Eye Research, 2017, 57: 46-75.


3) Normal tension glaucoma is a bit different.  Obviously it’s different in terms of intraocular pressure but let’s think about what causes glaucoma.  Well, there are two main theories: 1) the raised IOP squeezes the nerves until they die (the mechanical theory) and 2) there are issues with the blood supply, starving the nerves until they die (the vascular theory).  In normal tension glaucoma (NTG), the IOP is within normal limits (there’s nothing smooshing the nerves to death) so we can assume that the vascular theory is probably more applicable to NTG.

It’s been found that NTG patients tend to present with deep, well defined visual field defects that tend to be closer to fixation than those found in high tension glaucomas.

Normal tension glaucoma is probably one of the most challenging diseases to diagnose in practice.  If someone comes in with IOPs around 30mmHg, we are immediately on alert.  But, and I came across this a few weeks ago, what if your patient has IOPs around 15mmHg, moderate cup to disc ratio, deep cupping, no sign of focal neuroretinal rim (NRR) loss, normal central corneal thickness and a family history of glaucoma? Well, you do a 24-2 (as I did) and you find no defects.  Case closed?

My optom-sense was tingling from the moment I saw a photo of the patient’s discs – even before I heard that his father was registered blind as a result of glaucoma.  So I did a 10-2 test and, yes, there was a deep defect relatively close to fixation.

Research has been done into visual field defect location and those with a defect within 5 degrees of fixation are at a greater risk of losing their visual acuity – this makes NTG even scarier! It’s certainly worth taking an extra five minutes and doing a 10-2 test if the 24-2 is unremarkable but your gut instinct tells you something is amiss.

Further reading: Cho H.-K., Lee J., Lee M. & Kee C. Initial central scotomas vs peripheral scotomas in normal-tension glaucoma: clinical characteristics and progression rates. Eye, 2014, 28: 303-311.


4) Glaucoma doesn’t just affect the eye.  This is something I’d never really thought about until recently but what happens when those ganglion cells die? It creates dead space in the visual cortex.

You know that glaucoma is a disease which causes a negative scotoma (as opposed to the positive scotoma that results from advanced AMD) – why? Because the brain fills in the missing areas with information from around the scotoma.  When we talk about glaucoma, we may imagine tunnel vision but that’s not actually what patients say they experience.  They have blurred bits and missing bits.  It’s like that trick we do where we draw a small cross on a piece of paper then move it across our visual field until it disappears – that’s the cortex producing a negative scotoma so we aren’t aware we actually have a blind spot.

Of course, the cortex isn’t really doing us any favours when it comes to glaucoma – it’s hiding the disease from the patient and even when diagnosed, it’s sometimes difficult to convince a patient that they have an issue with their vision (especially when it comes to something as important as driving).

So, please don’t tell your patients that they have brain damage as well as glaucoma, but maybe be more aware that the visual experience of someone with the disease is different from what you may believe.  When those patients (and I’ve had my share) come in and say “something just isn’t right” then maybe think of glaucoma as a possibility – especially if they have normal IOPs.

Further reading: Crabb, D.P. A view on glaucoma – are we seeing it clearly? Eye, 2016, 30: 304–313.


5) Over 111 million people will be living with glaucoma by 2040.  I’ll just leave that there.

Further reading: Tham, Y.-C., Li, X., Wong, T.Y., Quigley, H.A., Aung, T., Cheng, C.-Y. Global prevalence of glaucoma and projections of glaucoma burden through 2040. Ophthalmology, 2014, 121, 2081–2090.


* If you are a Scottish optometrist, you can get access to Athens through your health board so you can read these papers for free.  If anyone in Wales, England or NI knows if this is also the case, please comment.

** Or men, I’m not being sexist here.