1. UBC Ophthalmology Club 2012
Chronic Visual Loss
Objective:
Introduce 4 common conditions causing chronic vision loss and describe cardinal features of each
Highlight the preventability/treatability of each
Emphasize the role of primary care in screening and referral of patients
UBC Ophthalmology Club
2012

2. Approach History, physical, tests
Patient population tends to be the elderly, but 2% of adults in the US over age 40 have vision <20/40 (Congdon et al Arch Ophthalmol 122(4): )
Prevalence increases with age
Early detection may lead to early intervention and preservation of vision
Primary care is the first screen, know when to refer

3. Case 1 Exam: 55M comes to GP for routine physical
OD 20/30 OS 20/30 (both 20/25 2 years ago)
Pupils equal reactive
No RAPD
EOM full
Confrontational VF grossly intact
55M comes to GP for routine physical
Has HTN, currently on thiazide
Denies visual loss, eye pain, headaches
Sister was taking an eye drop but not sure what that’s for
Would it be common or uncommon to detect a VF defect in confrontational field testing? If detected what’s the shape of the defect typically?
Glaucoma usually affect inferior disc leading to superior field, which pt usually don’t notice

4. Case 1 Management: A. This pt needs urgent treatment to lower his IOP
B. Refer pt to ophthalmologist 1-2 weeks
C. Reassess pt in 3 months
D. Increase his thiazide dose and consider adding a second antihypertensive
Ans: B
Discuss dx, confirm it first with audience, then present with management options
Photo courtesy Dr. Fred Mikelberg

5. Transillumination defect. (Kuo & Noecker, AAO 2009)
Pseudoexfoliation. (Shaw, AAO 2003)

6. Primary Open Angle Glaucoma
Progressive optic neuropathy of unknown etiology with persistent VF defect
Risk factors incl. elevated IOP, family hx, race, age, myopia
Sx incl. gradual loss of peripheral visual field
Further tests:
VF testing of this pt reveals nasal step defect
IOP: OD 29mmHg, OS 23mmHg
Retina tomography shows moderate thinning of nerve fibre layer
AAO recommends refer pt when:
disc:cup >0.5 or one cup significantly larger than the other
IOP > 21mmHg or >5mmHg difference between the eyes
Sx of acute glaucoma
Note: there are many causes of secondary glaucoma. Look for signs eg. rubeosis, pseudoexfoliation, transillumination defects, shallow AC
May or may not have IOP
African american, high myop high risk group
Pt usually not going to c/o sx, use Fhx to screen
Tx:

7. Common Rx for glaucoma The only pharmacological target is lowering IOP
Alpha agonists(↑drain, ↓aq): clonidine, brimonidine
Beta blocker (↓aq): timolol
CA inhibitor (↓aq): acetazolamide (Diamox)
Prostaglandin analog (↑drain): latanoprost (Xalatan)
SE of PG analog- iris color change and longer eye lashes

8. Case 2 70M c/o decreasing vision in both eyes over last 6 months to GP
This is particularly bothersome as he is having more trouble reading and watching TV
No eye conditions in the past
Hx significant for obesity and 50 pkyr smoking, quit 5 years ago
Family history unremarkable
May or may not have fhx

9. Case 2 OD 20/80, OS 20/100 (last 2 years decreased)
Pupils equal reactive
EOM full
CVF intact
IOP within normal limits
Fundoscopy:
Amsler grid:
(Khanifar et al. Retinal Physician, 2007)

10. What do you tell this patient?
A. he has missed the window for effective intervention
B. he needs immediate antioxidant and zinc supplement
C. his children are at increased risk of this disease
D. his condition probably won’t cause complete blindness
Ans: D
Pt may develop wet amd resulting in rapid loss of central vision over days, must treat immediately. 40% will return to baseline.
1/10 with dry can develop into wet

11. Age Related Macular Degeneration
2 forms: atrophic (dry) and exudative (wet)
Leading cause of blindness in adults >75 yr, mostly from exudative form
Multifactorial disease, see characteristic drusen
Early diagnosis enables detection of exudative form, which can be effectively treated with anti-VEGF agents
Screening in primary care:
Visual distortions, especially in central vision
Presence of drusen in macula, retinal pigment breakdown
Refer to ophthalmologist for full evaluation

12. Wet AMD Monthly injection, $1600 per shot
Risk of wet includes large confluent drusen (>125um), pigmentary abnormalities. Smoking and white race are also associated with higher risk (AREDS).
Monthly injection, $1600 per shot

13. Case 3 68F comes to GP with c/o decreased vision in her L eye
She denies double vision or glares, in fact she said she can read better with her L eye than her R eye now; she wants to know if her reading glasses are still necessary
No eye disease or trauma
No family hx of eye diseases
Meds include prednisone 20 mg daily for last 2 months for RA flare

14. Case 3 OD 20/30, OS 20/50 Pupils equal reactive no RAPD EOM full
Confrontational VF full
Fundus visualized, unremarkable
Question what is the dx? cataract
(Espandar, AAO 2009)

15. Management What’s your course of action?
A. Inform pt that her cataract is the result of her prednisone use
B. This pt needs to see an ophthalmologist STAT because of risk of irreversible visual loss
C. This pt’s presbyopia is improving so she should be followed up in 6 months at your office
D. Referral to ophthalmologist for evaluation and treatment options
Systemic prednisone usually cause Posterior Subcapsular cataracts.  These are mainly opacification of the posterior capsule due to epithelial cells migration.  They tend to cause significant vision loss with lots of glare symptoms.  Posterior subcapsular cataracts tend to obscure the posterior pole quite early on
Nuclear sclerosis cataracts are mainly due to aging and they are the typical lens changes we see when the lens turn a yellow to dark brown colour.  They cause the lens central density to increase and cause a myopic shift and as you correctly stated, induces myopia and patients often reads better (though losing distance vision)
Most cataracts do not need STAT referral as they tend to be slowly progressing.  But if they cause other problems such as phacomorphic glaucoma or phacolytic glaucoma/uveitis, then they have to seen quite urgently

16. Cataract Etiology: opacified lens
Most commonly associated with increasing age, but also congenital, DM, steroid use, trauma, radiation
Pt complain of painless gradual unilateral vision decrease
“Second sight” refers to myopic shift as cataract increases power of lens; this is temporary
Referral to ophthalmologist when decrease in vision becomes symptomatic and/or interfere with function
Cataract removal+IOL implant is one of the most frequently-performed and successful procedures in all of surgery
Could be BL.

17. Other types of cataracts
Cortical cataract
Posterior subcapsular cataract
Implantable IOL

18. Case 4
63M with 17 yr hx of Type 2 DM comes to GP to c/o decrease in vision in both eyes
Denies pain, distortions, double vision
Hb A1c 7.5% despite being on metformin and gliclazide
Also has dyslipidemia, on atorvastatin
No previous eye complaints

19. Case 4 OD 20/40, OS 20/60 Pupils equal reactive, red reflex present
EOM full VF intact
AC deep and quiet
Fundoscopy:
Make sure this shows macular
lipid. moderate NPDR would not usually be
associated with vision loss in the absence of
some macular pathology. Also, type 2 often is
present for many years prior to diagnosis.
Important as retinopathy tends to develop
10-15 years after diagnosis
(AAO, 2012)

20. Diagnosis What is the cause of this pt’s decreased vision?
A. Non-proliferative diabetic retinopathy
B. Age related macular degeneration
C. Proliferative diabetic retinopathy
D. Branch retinal vein occlusion
Ans: A: NPDR ft: 1st sign is microaneurysms, then hard exudates, cotton wool spots, dob blot hemmorhage, venous beading, CSME.

21. Diabetic retinopathy Microvascular complication of DM
Most common cause of vision loss in adults yr
In NPDR, vision loss arise from macular edema
In PDR, vision loss can be rapid, secondary to scarring and vitreous hemorrhage
Ophthalmologist referral when:
Newly diagnosed DM patient
Eye exam every 1-2 years after
Patient who develop rapid vision change
Glycemic control is the cornerstone of systemic management. DR is managed with laser and anti-VEGF
Will have CSME in NPDR with vision loss
Guideline: baseline eye exam, then q1-2 yr
Type 1: 5 years after dx, then q1-2 yr

22. PDR
Proliferative disease, characterized by formation of new and fragile vessels that form a tangle on the disc and elsewhere.
Pan-retinal photocoagulation uses laser to destroy ischemic retina in order to prevent neovascularization and preserve the macula.

23. Summary
4 most common causes of chronic visual loss and their features:
Open angle glaucoma- insidious, treat IOP
Age related macular degeneration- distortions, most common
Cataract- often unilateral, good result with surgery
Diabetic retinopathy- check in all DM pt, bilateral visual loss
All are either reversible or can be managed well (slow/stop vision loss) if detected early
Therefore, primary care’s role is vital in screening of chronic eye diseases

24. Questions? Edited by: Steven Schendel, PGY-4
Reviewed by: Drs. Fred Mikelberg, David Maberley, Francis Law
Contact:
R Tom Liu