BCSC 10-4: Glaucoma - Open-Angle Glaucoma Flashcards
(143 cards)
1
Q
Which one of the following sets of descriptors most accurately describe the clinical features of POAG?
A
- Insidious onset, slowly progressive, central vision loss, and usually bilateral. 2. Insidious onset, slowly progressive, painless, and usually unilateral. 3. Indsidious onset, slowly progressive, painless, and usually bilateral. 4. Sudden onset, rapidly progressive, painless, and usually bilateral.
2
Q
True or false? POAG is diagnosed by elevated IOP.
A
False. It is diagnosed by assessment of the optic disc and visual fields. The angle must also be open on gonioscopy.
3
Q
True or false? All patient evaluated for glaucoma should undergo baseline gonioscopy.
A
True.
4
Q
True or false? All patient with POAG should undergo periodic repeat gonioscopy?
A
True.
5
Q
Why should patients with POAG undergo periodic repeat gonioscopy?
A
To detect progressive angle closure caused by miotic therapy (also when miotic therapy is initiated) or age-related lens changes, especially in patients with hyperopia or a rise in IOP.
6
Q
What is the mean IOP in mm Hg? What is the standard deviation? What constitutes the “normal” range of IOP?
A
The mean IOP is 15.5 mm Hg with a standard deviation of 2.6 mm Hg. The “normal” range is ~10-21 mm Hg (or 2 standard deviation within the mean).
7
Q
Why type of the distribution is the classical “normal” IOP range? Why is this a misrepresentation of the IOP in the general population?
A
The classical “normal” range of IOP represent a Gaussian distribution. In reality, the distribution is skewed toward higher pressures.
8
Q
What percentage of patient with glaucomatous optic neuropathy have initial screening IOPs below 22 mm Hg?
A
30-50%
9
Q
By how many mm Hg can the IOP of patients with glaucoma vary over a 24 hour period?
A
10mm Hg or more. Typically range by 2-6 mm Hg.
10
Q
What are the subtypes of diurnal fluctuation patterns in glaucoma patients?
A
Morning, day, night, or flat (meaning little diurnal fluctuation).
11
Q
True or false? Most patients with glaucoma demonstrate “erratic” diurnal fluctuation?
A
False. Most patient with glaucoma demonstrate similar patterns from day to day.
12
Q
What percentage of patient with glaucoma demonstrate “erratic” diurnal patterns?
A
10-20% manifest different patterns of diurnal IOP fluctuation over time.
13
Q
What is thought to be associated with the increased IOP seen at night?
A
The shift from upright to supine posture maybe associated with increased nocturnal IOP.
14
Q
True or false? Spontaneous asymmetric fluctuations of IOP between eyes occur commonly in individual without glaucoma, but such fluctuation are uncommon in glaucoma patients.
A
False. Spontaneous asymmetric fluctuations of IOP between eyes occur commonly in individual with glaucoma and without glaucoma.
15
Q
True or false? Elevated IOP is a strong risk factor for glaucoma progression.
A
True.
16
Q
True or false? Large diurnal IOP fluctuations are a risk factor for glaucoma progression.
A
Unknown. The studies results have been conflicted.
17
Q
True or false? Increased corneal thickness has been associated with increased IOP?
A
False. Increased corneal thickness resists indentation in nearly all methods of IOP measurement, resulting in artificially high measurements. The opposite occurs in eyes with low corneal thickness.
18
Q
What is the average central corneal thickness in adults?
A
530-540 μm
19
Q
True or false? On average, persons of African ancestry have lower CCT than Caucasians?
A
True.
20
Q
Describe the condition termed ocular hypertension?
A
Elevated IOP in the absence of identifiable optic nerve damage or visual field loss.
21
Q
True or false? Lower CCT has been found to be a risk factor for conversion of OHT to glaucoma.
A
True. Lower CCT has also been found to be a risk factor for progression of POAG. Maybe due to underestimated IOP measurement or may represent a bio marker for disease susceptibility
22
Q
True or false? Visual field loss that does not need to correlate with optic disc appearance.
A
False. Additionally, any discrepancy in visual field loss and optic disc appearance requires further investigation.
23
Q
What was the prevalence of glaucoma in patient over 80 years old in the Baltimore Eye Survey?
A
11%.
24
Q
How many more times more likely were the glaucomatous visual field defects to progress in patients 60 years or older than those younger than 40 years in Collaborative Initial Glaucoma Treatment Study?
A
Seven times more likely to progress if 60 years old or older.
25
True or false? Age is an independent risk factor for development of glaucoma?
True. Even though IOP tends to increase with age, age appears to be an independent risk-factor.
26
True or false. The ocular hypertension study found no risk for progression from OHT to glaucoma with age.
False. 43% increased risk per decade in univariate analysis and 22% in multivariate analysis.
27
How many times more prevalent is POAG in black persons than in non-Hispanic white individuals?
3 to 4 times more prevalent.
28
How many times more prevalent is POAG in black persons than Hispanic persons?
POAG is about equally prevalent.
29
How many times more prevalent is POAG in Hispanic persons than in non-Hispanic white individuals?
3 to 4 times more prevalent.
30
True or false. The OHTS found that black persons have 59% higher life-time incidence of glaucoma than white persons regardless of other factors.
False. Multivariate analysis failed to show this relationship after CCT and baseline vertical cup-disc ratio were factored into the equation.
31
True or false? Black persons average vertical cup-disc ratio is smaller than white persons average.
True or false. On average, white persons have thicker central corneas than black persons.False. Black persons average cup-disc ratio is greater than white persons average.
False. Black persons average CCT is less than white persons.
32
What features associated with myopic eyes make evaluation of the optic disc particularly complicated?
Tilted disc, posterior staphylomas, and magnification of the disc associated with the myopic refractive error interfer with optic disc evaluation.
33
True or false? OHTS found an association between myopia and the development of glaucoma.
True.
34
High myopia (< 4D spherical equivalent) was an independent risk factor for development in what study?
Rotterdam follow-up study.
35
Myopia (< 1 D spherical equivalent) was a significant risk factor for glaucoma prevalent in which study?
Beaver Dam Eye Study.
36
Diabetes mellitus was found to be associated with OAG in which studies?
Beaver Dam Eye Study, Blue Mountains Eye Study, and Los Angeles Latino Eye Study.
37
Diabetes mellitus was found to have no associated with OAG in which studies?
Framingham Study, the Baltimore Eye Survey, the Barbados Eye Study, and Rotterdam Study (revised analysis).
38
Describe the finding of the Baltimore Eye Survey in regards to systemic hypertension as a risk factor for glaucoma.
The Baltimore Eye Survey found systemic hypertension was associated with a lower risk of glaucoma in patient < 65 years old and an increased risk for patient > 65 years old.
39
Describe the finding of the Barbados Eye Studies in regards to systemic hypertension as a risk factor for glaucoma.
The Barbados Eye Studies showed a decreased relative risk in all age groups with hypertension, even those > 70 years of age.
40
True or false? Decreased ocular perfusion pressure is associated with glaucoma.
True.
41
Describe the theory behind the association hypertension and decrease risk of glaucoma found in some studies?
With increase blood pressure comes increased optic nerve perfusion. Therefore, over treatment of systemic hypertension can decreased ocular perfusion pressure.
42
CRVO is associated with the development of what types of glaucoma?
Angle-closure, or, at later stages, neovascular glaucoma.
43
True or false. Glaucoma and OHT are risk factors for the development of CRVO.
True.
44
Name five other possible risk factors for the development of glaucoma for which more research is required to clarify the relationship?
Sleep apnea, thyroid disorders, hypercholesterolemia, migraine, and Raynaud phenomenon
45
True or false? Most POAG patients will retain useful vision for their entire lives.
True.
46
What is the estimated prevalence of bilateral blindness among persons with OAG?
8% in black persons and 4% in white persons
47
True or false? A patient with visual field defects at the time of diagnosis is not at greater risk of blindness from POAG.
False. Patients with visual field loss at diagnosis are at greatest risk of blindness.
48
The Early Manifest Glaucoma Trial (EMGT), a mean reduction of 25% in IOP reduced the risk of the glaucoma progression from ___ % to ___ % at ___ years?
62% to 45% at 6 years
49
Significant visual field progression occurred in only _____ of participants?
10-13%
50
Are open-angle glaucoma without elevated IOP, normal-tension glaucoma, and low-tension glaucoma all names refering to the same entity?
Yes.
51
True or false. Normal-tension glaucoma is normally bilateral.
True. It is normal bilateral, but is frequently asymmetric.
52
Which vasospastic disorders have been associated with patients with normal-tension glaucoma compared to patients with high-tension glaucoma?
Migraine headache, Raynaud phenomenon, ischemic vascular diseases, autoimmune diseases, and coagulopathies. However, these finding have not been consistent.
53
True or false. Optic disc hemorrhages are equally common among patients with normal-tension glaucoma and high-pressure glaucoma.
False. Optic disc hemorrhages are more common among patient with normal-tension glaucoma.
54
Name the two subtypes of normal-tension glaucoma.
Senile sclerotic and focal ischemic group
55
Describe the optic disc findings of the senile sclerotic subtype of normal-tension glaucoma?
Shallow, pale sloping of the neuroretinal rim (primarily seen in older patient with vascular disease)
56
Describe the optic disc finds of the focal ischemic subtype of normal-tension glaucoma?
Deep, focal notching of the neuroretinal rim
57
Describe the characteristic difference of visual field defect in normal-tension glaucoma versus POAG?
The visual field defects in normal-tension glaucoma tend to be more focal, deeper, and closer to fixation, especially early in the course.
58
True or false? A dense paracentral scotoma encroaching on fixation is not an unusual finding as the initial defect in normal-tension glaucoma.
True.
59
Discuss the reasons why a patient maybe missed diagnosed with normal-tension glaucoma when they have a form of high-tension glaucoma.
Diurnal variation, intermittent IOP elevation with angle-closure glaucoma or glaucomatocyclitic crisis, previously elevated IOP which has normalized, uses of medication that decrease IOP (eg, Beta-blockers), tonometry error (low corneal thickness,reduced scleral rigidity)
60
Name seven broad categories of nonglaucomatous optic nerve disease.
Congenital anomalies (coloboma, optic nerve pits), compressive lesions of optic nerve and chiasm, shock optic neuropathy, AION, retinal disorders (ie, RD, retinoschisis, RAO, RVO, chorioretinitis, syphilis, optic nerve drusen, toxic/nutritional optic neuropathy (eg, methanol)
61
Which ethnicity have studies shown to have a high proportion of OAG with IOP in the normal range?
Japanese
62
Which method of tonometery should be used to measure the pressure in patient with glaucoma or suspected glaucoma?
Applanation tonometery
63
What entities most gonioscopy be preformed on to rule out during evaluation of a patient with high IOP?
Angle closure, angle recession, or evidence of previous intraocular inflammation or pigment dispersion.
64
Describe the basic work-up for a patient presenting with high-IOP?
Applanation tonometery, gonioscopy, stereoscopic optic disc evaluation, visual fields, and optic nerve OCT.
65
What distinguishes optic nerve damage induced by prior topical steroids, in susceptible individuals, from that of normal-tension glaucoma?
Optic nerve damage induced by topical steroids is non-progressive once medication is discontinued.
66
What distinguishes visual field loss from prior shock, from that of normal-tension glaucoma?
Visual field deficits from prior shock are non-progress.
67
Name seven atypical finding for normal tension-glaucoma that warrant additional medical and neurological evaluation?
Unilateral disease, decreased central vision, dyschromatopsia, young age, the presence of a RAPD, neuroretinal rim pallor, or visual field loss not consistent with optic nerve appearance.
68
Describe the medical and neurological evaluation that should be conducted on a patient with visual field loss, normal IOP, and atypical findings for normal-tension glaucoma?
Tests for anemia, carotid artery insufficiency, syphilis, certain vitamin deficiencies, and temporal arteritis or other systemic vasculitis. Consider CT or MRI to evaluated for compressive lesions.
69
Collaborative Normal-Tension Glaucoma Study (CNGTS) found that lowering IOP by at least ____ reduced the 5-year risk of progression of visual field loss from ____ to ____.
CNTGS found that lowering IOP by at least 30% reduced the 5-year risk of progression of visual field loss from 35% to 12%.
70
CNTGS demonstrated that ___ of patient did not progress over the length of the study despite the lack of treatment and ___ progressed despite successful IOP reduction.
CNTGS demonstrated that 65% of patient did not progress over the length of the study despite the lack of treatment and 12% progressed despite successful IOP reduction.
71
What is the initial goal of treatment of normal-tension glaucoma and what factors should be taken into consideration?
Use currently available treatment to achieve an IOP level that is approximately 30% below a carefully determined baseline, with appropriate adjustments of the target pressure that take into account the baseline severity of optic nerve damage, the risks of therapy, and other relevant factors, such as life expectancy and comorbid conditions.
72
What two medications have been used to improve the success rate of filtering surgery?
Mitomycin C or 5-fluorouracil
73
Define glaucoma suspect?
An individual who has an optic nerve or nerve fiber layer defect suggestive of glaucoma in the absence of an abnormality in visual function as determined by perimetry; or who has a visual field abnormality consistent with glaucoma in the absence of a corresponding glaucomatous optic disc abnormality.
74
What optic nerve or nerve fiber layer defects make a patient a glaucoma suspect?
Enlarged cup-disc ratio, asymmetric cup-disc ratio, notching or narrowing of the neuroretinal rim, a disc hemorrhage, or a suspicious alteration in the nerve fiber layer (in the absence
75
True or false? Glaucoma suspects should undergo periodic evaluation of the optic nerve, retinal nerve fiber layer, but do not need periodic visual fields.
False. Glaucoma suspects should undergo periodic evaluation of the optic nerve, retinal nerve fiber layer, and visual fields.
76
What technologies may allow for earlier detection of glaucomatous visual function loss?
Short-wavelength automated perimetry and frequency-doubling technology perimetry, and pattern electroretinogram.
77
True or false? A glaucoma suspect with signs of optic nerve damage should be started on IOP lowering therapy?
False. In most cases ths patient should be closely monitored, and treatment should be intiated if signs of glaucomatous optic nerve damage is found meaning the patient has glaucoma.
78
Define ocular hypertension (OHT)?
A condition in which the IOP is elevated above an arbitrary cutoff value, typically 21 mm Hg, in the absence of optic disc, retinal nerve fiber layer, or visual field abnormalities.
79
True or false? The higher the IOP in OHT the greater the risk of developing glaucoma.
True. However, most patient with elevated OHT will never develop glaucoma.
80
What findings would change OHT to glaucoma?
Optic nerve damage including focal notching, asymmetry of cupping, optic disc hemorrhage, nerve fiber layer defects, or subtle visual field defects.
81
True or false. There is a consensus as to whether or not OHT should be treated?
False. Some practitioners, after assessing all risk factors choose to treat those at greatest risk of developing glaucoma.
82
Describe the set-up of the Ocular Hypertension Treatment Study?
In OHTS, patients 40-80 years of age with IOP between 24 and 32 mm Hg were randomized to observation or reduction of IOP by topical medications.
83
What percentage of patient in the OHTS treatment and the control group progressed to glaucoma in a 5-year period?
4.4% of patients in the treatment group and 9.5% the control group progressed to glaucoma respectively.
84
In OHTS, each millimeter of mercury of elevated baseline IOP increased the risk of glaucomatous change by _____.
10%.
85
In OHTS, each 0.1 increment in vertical cup-disc ratio, the risk was increased by ___.
32%.
86
OHTS identified identified what risk factors for development of POAG.
Older age, higher IOP, lower CCT, higher pattern standard deviation on standard automated perimetry, and higher cup-disc ration at baseline
87
True or false? The increased risk for glaucoma found with lower CCT in OHTS was completely accounted for by the artifactual error in measured IOP.
False. It is therefore hypothesized that lower CCT may be a marker for other susceptibility factors.
88
True or false. OHTS found family history to be significant risk factor for developing glaucoma.
False. However, this is widely thought to be due to inadequate assessment of this information, and clinicians should still consider the patient's family history when evaluating the patient's risk of developing glaucoma.
89
What other variables, outside of there risk factors, most be weighted in a OHT patient when deciding whether or not to initiate treatment?
Side effects, cost, inconvenience, desires of patient, patient compliance and availability for follow-up visits, reliability of visual fields, and ability to examine the optic disc.
90
The second study period of the OHTS involved placing the control group on IOP-lowering therapy after 5.5 years of median follow-up in order to attempt to answer what clinical question?
Whether initiating IOP-lowering therapy earlier or later affected progression to glaucoma?
91
What were the findings of the second study period of the OHTS where the prior control group was started on IOP-lowering therapy and both they and the intial treatment group were followed for another 6.5 years?
The second part of the OHTS found that 16% of the intial-treatment group and 22% of the late-treatment progressed to glaucoma.
92
What was the conclusion of the second study period of the OHTS where the prior control group was started on IOP-lowering therapy and both they and the initial treatment group were followed for another 6.5 years?
The second part of the OHTS concluded that clinicians may safely consider delaying the treatment of OHT, particularly among patients with lower risk of conversion to glaucoma.
93
True or false? Exfoliation glaucoma is a type of secondary open-angle glaucoma?
True.
94
What characterizes exfoliation syndrome (pseudoexfoliation)?
The deposition of a distinctive fibrillar material in the anterior segment of the eye.
95
Histologically, where does the fibrillar material deposit within the eye?
Histologically, this material has been found in and on the lens epithelium and capsule, pupillary margin, ciliary epithelium, iris pigment epithelium, iris stroma, iris blood vessels, and subconjunctival tissue. It has also been identified in other parts of the body.
96
Mutations in what single gene seem to be present in nearly all cases of exfoliation syndrome and exfoliation glaucoma?
LOXL1
97
True or false? Everyone with the disease-associated mutation in LOXL1 will have exfoliation syndrome.
False. The disease-associated mutation in LOXL1 is common in the general population, and most people with it will not have exfoliation syndrome.
98
What is the mechanism by which LOXL1 mutation is related to the development of exfoliation syndrome and exfoliation glaucoma?
Though the exact mechanism is unclear, it likely involves the reduced or abnormal synthesis of elastin fibers.
99
What is the proposed mechanism by which IOP elevation occurs in exfoliation glaucoma?
The IOP elevation is thought to be caused by the fibrillar material obstructing flow through and causing damage to, the trabecular meshwork or the uveoscleral pathway.
100
Why might exfoliation syndrome cause increase susceptibility of the optic nerve to injury.
Elastin is an important component of the lamina cribrosa. This may explain why the presence of exfoliation syndrome was shown to be a risk factor for conversion of OHT to glaucoma and for progression of OAG in EMGT.
101
Describe the characteristic deposits on the anterior lens capsule seen in exfoliation syndrome and the mechanism behind them?
Targetlike pattern on the anterior lens capsule with a central and a peripheral zone of deposition. The intermediate area is clear presumably due to the iris movement rubbing the material off the lens capsule.
102
True or false? The trabecular meshwork is non-pigmented in exfoliation syndrome as the deposited fibrillar material is clear.
False. The trabecular meshwork is characteristically heavily pigmented with brown pigment, usually in a variegated fashion.
103
What is the name of the inferior pigmented deposition, scalloped in nature that is often present anterior to the Schwalbe line in exfoliation syndrome.
Sampaolesi line.
104
Describe the Sampaolesi line seen in exfoliation syndrome and pigment dispersion syndrome?
Pigmented deposition in the inferior aspect of the anterior chamber angle, scalloped in nature that is anterior to the Schwalbe line.
105
Describe the typical iris transillumination defects seen in exfoliation syndrome.
Peripupillary atrophy leads to transillumination defects of the pupillary margin.
106
True or false? Pupil dilation is often poor with exfoliation syndrome.
True. This is important to consider when performing cataract extraction on exfoliation syndrome patients.
107
Define phacodonesis.
Vibration or quivering of the lens related to zonular weakness.
108
Define iridodonesis.
Vibration or quivering of the iris presumably from vibration of the lens related to zonular dehiscence (which can lead to lens subluxation and increased freedom of motion).
109
Define zonular dialysis. How is it quantified?
Zonular dialysis is dehiscense of the zonules from the lens capsule or ciliary body. IT is typically quantified by the number of clock hours involved.
110
What surgical technique should be consider in patient with significant zonular instability
If the patient has significant zonular instability, preoperative consideration of a polymethylmethacrylate capsule-supporting device (e.g., tension ring) is advisable.
111
True or false? Exfoliation syndrome is always bilateral.
False. It can be unilateral or bilateral with varying degrees of asymmetry.
112
50% of OAG in patient of _____ heritage are associated with exfoliation syndrome.
Scandinavian
113
Exfoliation syndrome is rare in persons younger than ____ years of age, and is most commonly seen in individuals older than ____ years.
50 and 70 years old respectively
114
True or false? The overall prognosis of exfoliation glaucoma is better than POAG.
False. Still, laser trabeculoplasty can be very effective, but the response in exfoliation glaucoma may not last as long as that in POAG
115
True or false? Lens extraction alleviates exfoliation syndrome.
False.
116
Describe pigment dispersion syndrome
Pigment dispersion syndrome consists of pigment deposition on the corneal endothelium in a vertical spindle pattern.
117
What is the name given to the pigment depositions on the corneal endothelium in a vertical spindle pattern seen in pigment dispersion syndrome?
Krukenberg spindle.
118
Where are the typical iris transillumination defects seen in pigment dispersion syndrome?
Iris pigment epithelium causes iris transillumination the characteristic spokelike defects in the mideripherally
119
What is the mechanism of the Krukenberg spindles seen in pigment dispersion syndrome?
The spindle pattern is caused by the aqueous convection currents and subsequent phagocytosis of pigment by the corneal endothelium.
120
True or false. The presence of Krukenberg spindles in necessary to make the diagnosis of pigment dispersion syndrome.
The presence of Krukenberg spindles is not absolutely necessary to make the diagnosis of pigment dispersion syndrome, and it may occur in other diseases, such as exfoliation syndrome.
121
Describe the typical pigment deposition in the anterior chamber angle seen in pigment dispersion syndrome?
Gonioscopy reveals a homogeneous, densely pigmented trabecular meshwork with speckled pigment at or anterior to the Schwalbe line often forming a Sampaolesi line.
122
True or false? The mid periphery iris is usually convex.
False. The midperipheral iris is often concave in appearance, bowing posteriorly, toward the zonular fibers.
123
Where other than the corneal endothelium are pigment deposits seen in pigment dispersion syndrome?
When the eye is dilated, pigment deposits can be seen on the zonular fibers, the anterior hyaloid, and the lens capsule near the equator of the lens.
124
What name is given to the pigment deposits on the lens capsule near the equator of the lens seen in pigment dispersion syndrome.
Zentmayer line
125
True or false? Pigment dispersion syndrome universally leads to glaucoma.
This syndrome does not universally lead to glaucoma. An individual with pigment dispersion syndrome may never develop elevated IOP.
126
Various studies have suggested that the risk of an affected individual developing glaucoma is approximately_____.
25%-50%.
127
Pigmentary glaucoma occurs most commonly in _____ _____ who have ____ and who are between the ages of ___ and ___ years.
Pigmentary glaucoma occurs most commonly in white males who have myopia and who are between the ages of20 and 50 years
128
True or false? Pigmentary glaucoma is characterized by wide fluctuations in IOP.
True. Pigmentary glaucoma is characterized by wide fluctuations in IOP which can exceed 50 mm Hg in untreated eyes. High IOP often occurs when pigment is released into the aqueous humor, such as following exercise or pupillary dilation.
129
What are the symptoms of pigmentary glaucoma?
Symptoms may include halos, intermittent visual blurring, and ocular pain.
130
What pupillary configuration is associated with pigmentary glaucoma?
Posterior bowing of the iris with "reverse pupillary block" configuration is noted in many eyes that have pigmentary glaucoma. This iris configuration results in greater contact of the zonular fibers with the posterior iris surface, with subsequent pigment release.
131
What prophylactic procedure has been proposed to relieve the posterior bowing of the iris with "reverse pupillary block" configuration noted in many eyes that have pigmentary glaucoma?
Laser iridotomy has been proposed as a means of minimizing posterior bowing of the iris. However, its effectiveness in treating pigmentary glaucoma has not been established.
132
True or false? With age, the signs and symptoms of pigment dispersion may decrease in some individuals.
True. As pigment dispersion is reduced, the deposited pigment may fade from the trabecular meshwork, anterior iris surface, and corneal endothelium. Transillumination defects may also gradually disappear.
133
What is the proposed mechanizes by which the signs and symptoms of pigment dispersion may decrease with age in some individuals?
Possibly as a result of normal growth of the lens and an increase in physiologic pupillary block, moving the iris forward, away from contact with the zonular fibers. Loss of accommodation may also be a factor.
134
True or false? Medical treatment is usually unsuccessful in reducing the IOP in patient with pigmentary glaucoma.
False. Medical treatment is often successful in reducing the IOP.
135
True or false? Patients respond reasonably well to laser trabeculoplasty although the effect may be short-lived.
True.
136
True or false? Laser trabeculoplasty in pigmentary glaucoma require more energy due to the heavy trabecular pigmentation within the angle.
The heavy trabecular pigmentation allows increased absorption of laser energy, in turn allowing lower energy levels for trabeculoplasty. Spikes in IOP may be seen more frequently with higher energy settings in pigment dispersion syndrome following laser trabeculoplasty.
137
True or false? Filtering surgery is usually successful in pigmentary glaucoma.
True. Filtering surgery is usually successful; however, extra care is warranted, because young patients with myopia may be at increased risk of hypotony maculopathy.
138
True or false? The lens may cause both open-angle and angle-closure glaucomas.
True.
139
Name the three types of open-angle, lens-induced glaucomas?
Phacolytic glaucoma, lens particle glaucoma, phacoantigenic glaucoma
140
Name the two types of angle-closure, lens-induced glaucomas?
Phacomorphic glaucoma, ectopia lentis
141
What is phacolytic glaucoma?
Phacolytic glaucoma is an inflammatory open-angle, lens-induced glaucoma caused by the leakage of lens protein through the capsule of a mature or hypermature cataract. The proteins precipitate a secondary glaucoma as they, along with phagocl'tizing macrophages and other inflammatory debris, obstruct the trabecular meshwork.
142
Describe the usual clinical picture and exam of a patient with phacolytic glaucoma.
The clinical picture usually involves an elderly patient with a history of poor vision who has sudden onset of pain, conjunctival hyperemia, and worsening vision. Examination reveals a markedly elevated IOP, microcystic corneal edema, prominent cell and flare reaction without keratic precipitates (KP), and an open anterior chamber angle. The lack of KP helps distinguish phacolytic glaucoma from phacoantigenic glaucoma. Cellular debris may be seen layered in the anterior chamber angle, and a pseudohypopyon may be present. Large white particles (clumps of lens protein) may also be seen in the anterior chamber. A mature or hypermature (Morgagnian) cataract is present, often with wrinkling of the anterior lens capsule representing loss of volume and the release of lens material. Although medications to control the IOP should be used immediately, definitive therapy requires cataract extraction.
143
What is an important clinical finding that helps distinguish phacolytic glaucoma from phacoantigenic glaucoma.
The lack of KP helps distinguish phacolytic glaucoma from phacoantigenic glaucoma. Of note, phacolytic glaucoma may present with a pseudohypopyon.
