Course 6261, OHP 1 Revised 2-6-2011 SAMPLE QUESTIONS Clinical Applications of VFs and Other 6261 Material These VF questions are based on material in: VF Screening & Analysis handouts (these are the two Powerpoint handouts on VFs that were distributed in class) and Section J (VF Screening in the PC Service) in the Course 6261 lecture manual 1. A 68-year old Chinese lady is scheduled for a comprehensive exam (92004); she has never been to ECC for an eye exam before. When she comes in she states that when she made the appointment last week she had been having some problems reading fine print so she is here for that problem. But another problem came up - when she woke up this AM she noticed that her vision was “different”. When she checked each eye she found that the vision in the right eye is “really blurred” and her vision is blurred to the right side in both eyes, particularly in the right eye. PEHx: She is not sure if her vision was normal before this morning and it has been about 6 years since her last eye exam. She says that she tries to stay away from doctors “because they’ll find something wrong with me and a lot of them are quacks”. PMHx: Long term HBP with marginal control. Diabetes mellitus (DM) x 10 years. She does not know the names of her medications. You find entering distance acuities of OD: 20/50 and OS: 20/25-2/5 through +3.00 Sphere OU/+2.50 Add. She got these glasses at her last exam 6 years ago. CT shows low exo at distance and near. Versions are normal. Count fingers confrontations shows VF loss to the right side of the vertical midline, in both the superior and inferior quadrants, in both eyes. You find the following on pupil testing: P 33 RRL1+2+ A 4+4+ 1+ APD OD On retinoscopy you note a moderate density central media opacity suggestive of moderate nuclear sclerotic cataracts (NSC) in both eyes but somewhat denser in the right eye. You see the same on distance ophthalmoscopy. Your refraction shows: OD: +2.00 Sphere 20/30+2/5 pinhole 20/30 +2.50 Add RS 30 OS: +2.50 Sphere 20/20+1/5 +2.50 Add RS 20 a. What is the most likely cause of the 1+ APD in OD? What is the most likely cause of the vision loss (failure to correct to 20/20) in OD? Why was the pinhole used for the right eye but not the left eye? b. If, on ophthalmoscopy, you could see the damage most likely causing these pupil findings, explain what you are most likely to see – where would the damage be and what would it look like? c. Briefly explain why these pupil findings are not due to a lesion of the right CN III? 1 d. Explain why the near pupil reflexes are tested and what the near pupil findings show (why they are useful) in this particular case? e. What type of exam should this patient have given the information that is in the case above? If this patient has VSP Standard Plan that has not been used in 6 years, will the exam that you have described be covered? f. List any risk factors for narrow angles that this patient has below. g. On slit lamp examination describe the type of illumination that should be used to determine that this patient does indeed have nuclear sclerotic cataracts rather than cortical or posterior subcapsular cataract. h. Describe the relationship between the NSC and the VF loss. i. Given your confrontation fields, describe the VF loss that is most likely to be found on a automated VF screening like a HFA Central 40 test, FDT C-20-5 test or Matrix N-30-5 test: j. What trial lens, if any, should be used to perform the VF screening at the DFE on the right eye on each of the following perimeters and VF test? HFA Central 40 test for OD FDT C20-5 test for OD Matrix N-30-5 for OD k. If you find a right homonymous hemianopsia where in the visual pathway would a lesion be that would cause both the VF defect and the pupil findings? 2 2. Describe the purpose of the VF screening that is performed as a part of the comprehensive exam. 3. List 4 possible causes of generalized depression of the VF a. b. c. d. Which of the following perimeters is less susceptible to showing VF misses that are the result of generalized depression of the VF and why? FDT (you key in the patient’s age and the instrument uses that to “customize” the VF to the patient) Dicon (the instrument samples the threshold of one point in each of the 4 quadrants) 4. A 30 year old lady comes with the complaint of blurred vision in her left eye which she noticed 4 days ago and has gotten worse gradually. Her vision is “fine” in the right eye. PEHx:: Last exam 2 years ago, got glasses for reading and studying. PMHx: Good health but is just getting over an upper respiratory infection that started last week. The entering habitual (uncorrected) distance acuities are: OD: 20/20+ (Someone forgot to take the near VAs) OS: 20/60 Count finger confrontations are normal but when the patient looks at your nose or your eye with her left eye it is very dim and blurry. The pupil findings are: P 55 RRL4+1+ A 4+4+ Normal lid positons a. List the two most likely sites of a lesion causing the pupils findings. b. For each of the two lesion sites above describe how pupils could be used to differentiate one site from the other? (What would be different about the pupil findings?) c. How might ophthalmoscopy be used to differentiate the two lesions (in a above)? 3 d. If the screening VF shows no misses in the right eye and the result for the left eye is as shown in the FDT C-20-5 field labeled Question 4 what is the type of VF loss present? e. If on red cap confrontations the patient reports the red cap is really blurry and pink, rather than red, for the left eye when she looks at the red cap. It is red in the right eye. What is the most probable cause of the VF loss? f. How good is the reliability of the VF test labeled Question 4? g. On the FDT C-20-5 VF test labeled Question 4: For OS what does False Pos Errors 1/3 mean and how are false positives tested? What impact, if any, might this have on the test interpretation? For OS what does Fixation Errors 1/3 mean and how are fixation losses tested? 5. A 60-year old gentleman has a carotid endartectomy. You see the scar on his neck just below the angle of his jaw. The surgery also results in the release of emboli which cause the VF loss shown in the VFs labeled Question 5. a. Describe the most probable pupil anomaly below. P RRL A APD b. Based on the VF loss shown in the VFs labeled Question 5, describe the possible location(s) within the visual pathway of a single lesion that could have caused it. c. What is the one location that could cause this VF loss and also cause signs in the ONHs? Describe the ONH damage. 6. For the VF loss shown in the VF labeled Question 6: a. Where is/are the lesion(s) that caused this? 4 b. What is the expected finding on the pupil testing? P RRL A APD c. What type of vision field loss is present in the right eye and what nerve fiber bundle was damaged to cause this type of VF loss? d. What is the name of the VF loss that is present in both eyes together? 7. List 4 possible causes of a reduced direct pupil light response. a. b. c. d. 8. A 65-year old lady comes in for a yearly exam. She complains of headaches that started about 6 months ago and have increased in intensity and frequency over the last several weeks. Last night she was awakened by the HA. When you ask what makes the HA worse: She states that she was cleaning out the garage yesterday but had to stop due to the pain which greatly increased when she bent over or lifted anything. She reports good vision but about a week ago she started having blurriness of her vision that lasts a second or two. She thinks she may need her glasses changed. PEHx: Last exam 2 years ago; nothing abnormal then . PMHx: Reports good health but has experienced transient bouts of nausea in the last week or two. She had it a couple of times yesterday. She thinks it might be a stomach virus. Last physical or physician visit about a year ago. The visual acuity is 20/20+ in each eye at distance. All of the entrance tests are normal except the cover test: 5 esophoria at distance and 1 exophoria at near. You find similar esophoria on your phorias in the phorometry. Pupils: P33 RRL 3+3+ A3+3+ -APD You do an automated VF screening rather than confrontations and it shows the HFA C40 results labeled Question 8 for OD and for OS. a. Where is/are the most probable location of the lesion(s) causing this VF loss and explain your answer? b. Is there any relationship between the VF loss and the patient’s chief complaint (HAs)? c. If you had performed confrontations what would type of confrontation testing would most likely detect this VF loss? 5 d. What is the expected finding on the ophthalmoscopy? 9. What is the sensitivity of count fingers confrontations to the type of VF loss caused by glaucoma? To VF loss caused by a post-chiasmal lesion? To ALL types of VF loss? 10. What are the appropriate instructions to the patient regarding when to hit the response button on each of the following perimeters? FDT (Frequency Doubling Tester) or the Matrix Humphrey Field Analyzer (HFA) 11. A 22 year old female optometry student comes in with the complaint of having experienced a particularly unusual migraine last night as she studied for the OHP 1 Final Exam. She has experienced migraines several times previously but this migraine was preceded by flashing jagged lines in the right VF of both eyes that lasted for nearly an hour. This is much longer than usual for her. Most important, even though the jagged lines and headache both stopped, she notices that she cannot see off to the far right side in the right eye. Otherwise her vision is back to normal and the headache is gone. The entering VAs are 20/10 in both eyes uncorrected. All entrance tests are normal including count finger confrontations. a. Since this is no “regular” patient but rather a very sophisticated observer that gives a very detailed description of a loss of the far temporal portion of the VF in OD you decide that you should test the VF. What is the most appropriate confrontation VF screening technique that should be used in this case? b. On which, if any, of the following screening tests that are commonly used at ECC for screening would detect the VF loss? If none, why none? Explain your answer. FDT C20-5 HFA Central 40 Matrix C24-2-5 c. Where is the most probable location of the lesion(s) that caused the VF loss? d. What, if anything, would you find on ophthalmoscopy for such a VF loss? 12. Describe the type of VF loss and the characteristic of the VF for a lesion in each of the following locations: 6 Optic nerve OD in the nasal rim at 3:00 A stroke of the very posterior tip of the occipital (visual) cortex on the right side Trauma to the right temporal region of the head that results in extensive damage to the visual radiations A dense cataract lesion A mass compressing the right lateral angle of the chiasm 13. A 49 year old patient comes in for a comprehensive exam in the PC Service. His complaint is only that his vision is a little blurred at near through his current PALs that he got at his last exam in 2006. His distance vision is good. He has no other complaints. You find all entrance tests to be normal. You refract him and get 20/20 vision at distance and near in both eyes with +0.25 more plus at near. On the VF screening you get the result for the FDT C20-5 VFs labelled Question 13. a. What % of normal (no VF loss) patients will miss the areas that are the darkest in the printout for each eye? There are two of these dark areas (missed areas) for the right eye and two for the left eye. What % of normal patients would miss any one of these two points in each eye? b. For each of the 4 VF territories that we discussed in class discuss the likelihood of the VF loss being in that territory based on the pattern of the misses (Do the misses have a pattern similar to the VF loss in one or more of the 4 territories of the visual pathways)? c. What is the appropriate management of this patient at the point that you see this result print out from the FDT? d. Where could the damage be that caused these VF defects if the VF defects were due to real, organic damage rather than artifact? e. If the VF loss is due to glaucomatous damage to both ONHs which test in your entrance tests would most likely have found it if you had been very careful and how would it have shown up on this test? f. On tonometry with NCT you get: OD: 18, 15, 17 and OS: 17, 18, 17 at 9:15 AM. Can the patient have open angle glaucoma with these IOPs? 7 14. This 64-year old gentleman (see the HFA C40 VFs labeled Question 14) suffered head trauma in a motor vehicle accident 3 months ago and comes in with the complaint that his vision in both eyes is “not quite right” since the accident. He cannot be more specific about what is “not quite right”. He states that he was seen several times by a neurologist and the neurologist did that finger counting test and stated that everything is OK with his visual field. His last exam was about 15 months ago in your office and everything was normal then except mild nuclear sclerotic cataracts in each eye. His mother has very bad glaucoma and is blind in one eye. VAs with habitual Rx are 20/20 in each eye both at distance and near. Count finger confrontations are as the neurologist stated normal. Pupils are 3 mm OU with 4+ light responses. You feel like the left pupil redilates slightly more quickly on the SFLT than OD. NCT: 20, 22, 24/ 25, 27, 29 a. Given the VF defect evident in the HFA Central 40 screening test where is the most probable location of the head trauma? b. Are the VAs likely to be 20/20 with this VF loss? c. What is the most probable cause of the pupil findings? d. What information is missing from the NCT recording? Why is this information important? e. What are the possible causes of the asymmetry in IOPs in this case? f. Is there any evidence of glaucomatous VF loss in this case? If so where would you look to determine if it is due to glaucoma? 8 9 10 11 12