Ординатура / Офтальмология / Учебные материалы / Atlas of Glaucoma Second Edition Choplin Lundy 2007
.pdf
202 Atlas of glaucoma
Figure 14.2 Developmental glaucoma, gonioscopic view. Note concave peripheral iris profile with ‘wrap around’ configuration.
Figure 14.3 Iris hypoplasia. The superficial stroma is thin, especially in the inferior periphery, and there is hypoplasia of the sphincter muscle.
Figure 14.4 Gonioscopic view of anomalous vessels on iris
surface.
Figure 14.5 Gonioscopic view of normal iris surface vessels for comparison. Note exposed greater iris circle vessels, which are commonly seen in patients with light-colored irides.
Figure 14.6 Spontaneous lens subluxation in a 12-month-old |
Figure 14.7 Microcornea OS in patient with Rieger’s anom- |
|
aly and bilateral glaucoma. |
||
infant with primary congenital glaucoma and buphthalmos. |
||
|
The developmental glaucomas 203
Figure 14.8 Sclerocornea.
Figure 14.9 Axenfeld’s anomaly, gonioscopic view. T-shaped strands of iris tissue bridge over the angle recess up to Schwalbe’s line.
(a) |
(b) |
Figure 14.10 Axenfeld’s anomaly with posterior embryotoxon. (a) The posterior embryotoxon seems to have been pulled from the angle wall, so that it lies over the iris surface like a clothesline. (b) Gonioscopic view shows the suspended embryotoxon as a refractile rope with multiple strands of iris attached to it.
Iris/corneal anomalies
Axenfeld/Rieger/Peter’s comprise a group of conditions known as anterior segment dysgenesis syndrome to reflect their proposed etiology. Recalling that corneal endothelium, trabecular meshwork, Schlemm’s canal, and the iris stroma all develop from neural crest tissue, it is hypothesized that altered embryologic development of neural crest tissue leads to the spectrum of clinical findings in this group of diseases.
Axenfeld’s anomaly (Figures 14.9 and 14.10) is characterized by T-shaped iris strands drawn up to a prominent Schwalbe’s line as well as anterior iris stromal atrophy. It is bilateral with an autosomal dominant inheritance pattern. Up to 50% of patients may develop glaucoma that presents in infancy or later.
Rieger’s anomaly is further along this clinical spectrum and shares many of the findings of Axenfeld’s with a greater degree of anterior iris stromal atrophy. Findings include polycoria, corectopia and pupillary distortion. Like Axenfeld’s anomaly (and unlike iridocorneal endothelial syndrome), it is bilateral with an autosomal dominant inheritance pattern. Glaucoma is present in roughly 50% of patients with onset in infancy or later. Non-ocular anomalies may also be present and include dental (hypoand microdentia), facial (hypotelorism, malar hypoplasia), and systemic findings (short stature, cardiac defects, empty sella, deafness, and mental deficiency) (Figures 14.11, 14.12, and 14.13). The term Rieger’s syndrome is used when both ocular and systemic findings are present.
204 Atlas of glaucoma
Figure 14.11 Rieger’s anomaly. Note adhesions extending to the mid-periphery of the cornea. A posterior embryotoxon is prominent in the superior quadrant.
(a)
Figure 14.12 Rieger’s anomaly. There are wide adhesions and the cornea is hazy in the affected areas.
(b)
Figure 14.13 Rieger’s anomaly. (a) Note marked iris hypoplasia with thinning of the peripheral anterior iris stroma allowing view of the posterior pigmented epithelium. (b) Transillumination defect of iris at 8 o’clock position.
Peter’s anomaly is characterized by a central corneal opacity and adhesions between the iris collarette and corneal endothelium. Often there is absence of corneal endothelium and Descemet’s membrane as well as stromal thinning underlying the central corneal opacity. Lenticular opacity may be present as well. Even in the presence of normal-appearing angle structures, 50% of patients will develop open angle glaucoma. Glaucoma may present in infancy or later (Figure 14.14).
Iris anomalies
Aniridia is a bilateral inherited ocular abnormality caused by mutations in the PAX 6 gene which may occur sporadically or with an autosomal dominant pattern. The sporadic form is associated with a 20% prevalence of Wilms’ tumor (Miller syndrome).
Figure 14.14 Peter’s anomaly. Note the central corneal opacity and iridocorneal adhesions.
|
The developmental glaucomas 205 |
||
|
|
|
|
In addition to glaucoma, ocular findings include: |
pupillary block can occur with release of pigment |
||
rudimentary stump of iris, corneal pannus, |
and debris, further compromising outflow. Glaucoma |
||
cataract, ectopia lentis, optic nerve and foveal |
occurs in about 50% of patients and is managed |
||
hypoplasia, and nystagmus (Figures 14.15, 14.16, |
medically. Patients in whom pupillary block plays |
||
and 14.17). The mechanism for intraocular pres- |
a significant role may benefit from laser peripheral |
||
sure elevation may be adhesion of the iris stump to |
iridotomy (Figure 14.18). |
||
trabecular meshwork with progressive angle clo- |
|
|
|
sure (late), or a primary trabeculodysgenesis (early). |
Lens |
||
Glaucoma usually presents in the first three decades |
|||
of life. |
Microspherophakia may occur as an isolated finding |
||
Iridoschisis usually occurs after the sixth |
or in association with systemic syndromes (see below). |
||
decade of life, but occasionally is seen in children. |
Clinically, the edges of the small spheric lens can be |
||
There is bilateral patchy iris dissolution in which |
seen through the mid-dilated pupil. Other typical |
||
the anterior stroma separates from the posterior |
findings are high myopia and a shallow anterior |
||
stroma, most often in the inferior quadrants. Iris |
chamber in a young person. Zonular laxity can lead |
||
strands from the anterior iris stroma may project |
to pupillary block with acute or chronic angle closure. |
||
into the angle, causing peripheral anterior synechiae, |
Miotics make the pupillary block worse, since they |
||
and leading to pressure elevation. Alternatively, |
result in further anterior lens displacement. |
||
(a) |
(b) |
Figure 14.15 Aniridia. (a) Slit-lamp view; (b) gonioscopic view. The angle is open.
Figure 14.16 Aniridia, gonioscopic view. There is a periph- |
Figure 14.17 Aniridia, partial, slit-lamp view. |
eral iris stump only. Note lens opacity with anterior pyramidal |
|
cataract. |
|
206 Atlas of glaucoma
Globe: nanophthalmos |
Sturge–Weber syndrome |
|
The nanophthalmic eye is small but normally |
The hallmark of the Sturge–Weber syndrome is the |
|
shaped (Figure 14.19). Small corneal diameter and |
hemangioma. Facial hemangiomas are most com- |
|
short anterior–posterior length combined with a |
mon and occur in the distribution of cranial nerve V. |
|
normal-sized lens leads to anterior segment crowd- |
When cranial hemangiomas are present, there may |
|
ing and angle-closure glaucoma in the fourth to |
be an associated seizure disorder. Ocular findings |
|
sixth decades. Increased scleral thickness may lead |
include lid, choroidal and episcleral hemangiomas |
|
to choroidal effusions, which can occur sponta- |
(Figure 14.20). Glaucoma may occur due to primary |
|
neously or following filtering surgery. |
angle dysgenesis (early) or increased episcleral venous |
|
|
pressure (late). Filtering surgery, which carries an |
|
Systemic anomalies |
increased risk of suprachoroidal hemorrhage, should |
|
be undertaken with great caution in patients with |
||
Lowe’s syndrome |
||
evidence of increased episcleral venous pressure |
||
Lowe’s syndrome is an X-linked recessive condi- |
such as blood in Schlemm’s canal or dilated epi- |
|
tion with findings of aminoaciduria and mental |
scleral vessels. |
|
retardation in affected males. Characteristic ocular |
|
|
findings are cataracts and open-angle glaucoma in |
Neurofibromatosis (von Recklinghausen’s |
|
infancy. |
||
disease) |
||
|
||
|
Neurofibromatosis is an autosomally inherited |
|
|
condition characterized by multiple neurofibro- |
|
|
mas, pigmented skin lesions (café au lait spots), |
|
|
osseous malformations and associated tumors of |
|
|
the brain, spinal cord, and optic nerves. The skin |
|
|
neurofibromas may involve the eyelids, and glau- |
|
|
coma occurs most commonly in this setting. The |
|
|
glaucoma may be due to a primary angle dysgenesis, |
|
|
synechial angle closure from neurofibroma tissue |
|
|
on the iris, or from direct infiltration of the angle |
|
|
by iris neurofibroma tissue. |
|
|
Lens malposition syndromes |
|
|
Several systemic conditions are associated with |
|
|
lens malposition and resulting pupillary block. |
|
|
Attenuated and broken zonules can lead to bilateral |
|
|
lens subluxation or complete dislocation into the |
|
|
anterior chamber (Figure 14.21). Lens subluxation |
|
Figure 14.18 Iridoschisis in a 70-year-old patient with senile |
is typically superior in Marfan’s syndrome and |
|
cataract. |
inferior in homocystinuria. |
(a) |
(b) |
Figure 14.19 Nanophthalmos. (a) Note small-appearing eyes. (b) The patient wearing phakic spectacles.
The developmental glaucomas 207
(b)
(a) |
(c) |
Figure 14.20 Sturge–Weber syndrome. (a) External examination. There is extensive facial hemangioma involving the first and second branches of the trigeminal nerve. Note left hemifacial hypertrophy and buphthalmos in the left eye secondary to elevated intraocular pressure. (b) Normal fundoscopic examination of the right eye. (c) Fundoscopic examination of the left eye with cupping of the optic nerve and ‘tomato catsup’ choroidal hemangioma.
Marfan’s syndrome has an autosomal dominant inheritance and is characterized by arachnodactyly and tall stature. In addition to lens malposition and glaucoma, other ocular findings include microphakia, myopia, and retinal detachment. Systemic abnormalities include cardiac valve defects and congenital weakness of the aorta, which may lead to the development of dissecting thoracic aortic aneurysms.
Homocystinuria is a rare autosomal recessively inherited defect of the enzyme cystathione synthetase. Patients are characteristically lightly pigmented and may have osteoporosis, mental retardation, and seizures as well as tall stature. General anesthesia carries a significant risk of thrombotic vascular occlusions and should be avoided in these patients.
Patients with Weill–Marchesani syndrome exhibit short stature with short fingers and microspherophakia.
PATIENT HISTORY AND EXAMINATION
Historical information that should be obtained includes: time of symptom onset, previous medical or surgical treatment, family history of glaucoma, family history of ocular or systemic congenital abnormality, perinatal history (gestation, maternal infections, drug use, delivery), and consanguinity.
The examination of the patient is crucial for diagnosis and management, since most decisions and treatment options will be formulated solely on the basis of measured objective findings. The collection of objective findings can be performed at three levels: office evaluation, examination under sedation, and examination under anesthesia. The choice of examination level is made according to the patient’s age and degree of co-operation, the ability and habits of the examining ophthalmologist as well as
208 Atlas of glaucoma
(a) |
(b) |
Figure 14.21 Homocystinuria with dislocation of the lens. Homocystinuria with dislocation of the lens into the anterior chamber (a) and (b).
the anticipated amount of ocular manipulation. Below 6 months of age, a reasonably detailed examination can be carried out by pacifying the infant with feeding. After the crying triggered by administration of topical anesthetics has subsided, intraocular pressure measurement and gonioscopy are often possible without sedation. More complete examination (axial length, fundus photography, etc.) may warrant sedation or anesthesia with its attendant effects on intraocular measurement (see below).
Examination should commence with the nonocular structures to include the body, head, face, and extremities. Non-ocular findings may help make the diagnosis of a systemic syndrome associated with developmental glaucoma (see Figures 14.22 to 14.26). Attention is then directed to the ocular examination beginning with assessment of visual function (acuity, nystagmus, and amblyopia) as well as determination, if possible, of gross visual field defects.
Intraocular pressure may be measured in a number of settings and by a variety of methods. In the office, the young (less than 6 months old) infant can usually undergo accurate measurement with topical anesthetic while nursing. The Tonopen or Schiotz tonometer are most commonly used in this setting. For infants under sedation or general anesthesia, the Perkins type or the pneumotometer are additional methods (Figures 14.27, 14.28). Since most sedatives do not have a corneal anesthetic effect, use of topical anesthetic should be considered. During examination under general anesthesia, the best time for tonometry is right after induction. There are numerous factors which affect tonometry measurements regardless of the method used, including sedation and anesthesia, corneal abnormalities, and positive pressure on the periocular tissues (Figures 14.29, 14.30).
Figure 14.22 External examination of an infant with Klippel–Trenaunay Weber syndrome and bilateral developmental glaucoma. Note hemangiomas of trunk and limbs.
The external examination often reveals the characteristic triad of photophobia, buphthalmos, and epiphora secondary to elevated intraocular
The developmental glaucomas 209
|
pressure-induced globe and corneal enlargement |
|
|
(Figures 14.31, 14.32). Corneal enlargement and |
|
|
decompensation with edema may be reversible |
|
|
with effective lowering of intraocular pressure |
|
|
(Figure 14.33). Corneal diameter is measured and |
|
|
monitored as an indication of long-term intraocular |
|
|
pressure control in young children (Figure 14.34). |
|
|
Beyond the age of 3–4 years, there is limited enlar- |
|
|
gement, because the sclera and cornea are less dis- |
|
|
tensible. Dramatic changes may be seen in patients |
|
|
with advanced disease resulting in corneal ectasia |
|
|
or scleral thinning (Figures 14.35, 14.36). Often, a |
|
|
less obvious degree of scleral thinning is present in |
|
|
these children, posing a risk of inadvertent perfora- |
|
|
tion with scleral incisions and suture passes dur- |
|
Figure 14.23 Head and neck examination of a patient with |
ing glaucoma filtering and shunt surgery. |
|
developmental glaucoma. Note earlobe malformation |
Penlight examination of the cornea may reveal |
|
and scalp fibroma. |
gross abnormalities such as an opacity or an irregular |
|
|
light reflex indicative of corneal edema. Slit-lamp |
|
|
examination (Figure 14.37) permits a more detailed |
|
|
examination of the cornea and other anterior segment |
|
|
structures. Corneal findings include epithelial and |
|
|
stromal edema and breaks in Descemet’s membrane. |
|
|
When Descemet’s membrane is overstretched by |
|
|
pressure-induced corneal enlargement, linear breaks |
|
|
may occur. These breaks can result in acute stromal |
|
|
edema with accompanying photophobia (Figure |
|
|
14.38). Since both edges of the ruptured membrane |
|
|
roll up when the cornea eventually clears, a typical |
|
|
pattern of rail-like defect is evident at the level of |
|
|
Descemet’s membrane. Breaks occurring in con- |
|
|
genital glaucoma are known as Haab’s striae and |
|
|
are characterized by a horizontal orientation or a |
|
|
location parallel to the limbus (Figure 14.39). They |
|
Figure 14.24 External examination in a patient with oculo- |
are usually seen in the setting of elevated intraocu- |
|
lar pressure and enlarged corneal diameter (greater |
||
dermal melanocytosis involving the second branch of the |
than 10.5 mm in the horizontal meridian in the |
|
trigeminal nerve and elevated intraocular pressure of the left |
||
newborn infant). On the other hand, breaks due to |
||
eye. Note pigmentation of the left lower lid and |
||
birth trauma tend to run in any direction and are |
||
sclera/episclera. |
||
accompanied by normal intraocular pressure and |
||
|
||
|
normal corneal diameters (Figure 14.40). Iris abnor- |
|
|
malities such as atrophy and abnormal vessels are |
|
|
noted and the anterior chamber depth is assessed |
|
|
(Figure 14.41). Lens clarity and position are noted |
|
|
as well as any evidence of phakodinesis. |
|
|
Gonioscopy can be performed with an indirect |
|
|
gonioprism or a direct goniolens (see Chapter 5). The |
|
|
Zeiss four-mirror gonioprism or a direct goniolens |
|
|
(Koeppe or Layman) is preferred over the Goldman |
|
|
lens since no contact gel is required. Impaired visi- |
|
|
bility from contact gel may hinder posterior pole |
|
|
examination or anterior segment trabecular incisional |
|
|
surgery. Advantages of the direct goniolens include |
|
|
a magnified, 360 , distortion-free view of the angle in |
|
|
addition to a view of the posterior pole through the |
|
|
undilated pupil. The lens also stabilizes the globe in |
|
Figure 14.25 External examination of a patient with Sturge– |
the awake (co-operative) patient with nystagmus or |
|
Weber syndrome. Note the right facial hemangioma |
acts as a lid speculum in the sedated/anesthetized |
|
involving the second branch of the trigeminal nerve. |
infant (Figure 14.43a). Light and magnification are |
210 Atlas of glaucoma
(a) |
(b) |
Figure 14.26 External examination of patient with developmental glaucoma and polydactyly. (a) Of feet, and (b) of hands.
Figure 14.27 Perkins applanation tonometer. The counterbalance modification to the Goldmann applanation tonometer allows measurement of intraocular pressure in the supine position during examination under anesthesia.
Figure 14.28 Pneumotonometer in use to measure intraocular pressure during examination under anesthesia.
45
35
25
15
10
5
(a) |
(b) |
Figure 14.29 Tonometry artifacts, corneal abnormalities. In this eye, differing tonometry tracings were obtained over normal and abnormal cornea. (a) External corneal examination. (b) Tonometry tracings. (Photographs courtesy of M Jaafar, MD, Washington, DC.)
The developmental glaucomas 211
Figure 14.30 Tonometry artifacts, tight lids. When the lid fissure is very small, one might artificially increase intraocular pressure by applying pressure to the lids. This illustrates a method of opening the fissures by placing cotton-tipped applicators over the bony orbits to minimize this artifact.
Figure 14.31 Epiphora and corneal diameter enlargement in a child with congenital glaucoma.
(a) |
(b) |
Figure 14.32 |
Buphthalmos in right eye of child with congenital glaucoma. (a) Right eye. (b) Normal left eye. |
obtained by means of either a portable slit lamp, the operating microscope or a light source coupled with binoculars (Figure 14.43). In normal infants, the trabecular meshwork has a pinkish, moist, transparent appearance. In trabeculodysgenesis, the color is more white/gray. However, since the normal infant angle features are often indistinguishable from primary trabeculodysgenesis, the diagnosis of developmental glaucoma cannot be ruled out solely on the basis of a ‘normal’ angle. Noteworthy angle features include the profile of the peripheral
iris, the true level of the iris insertion, visibility of the scleral spur and ciliary body band, presence of a prominent Swalbe’s line (posterior embryotoxin), presence of a membrane over the angle, iris strands or adhesions, and angle vessels (Figures 14.44 to 14.51).
A dilated fundus examination is recommended unless goniotomy/trabeculotomy is planned during the same anesthesia. In eyes with small pupils, hazy cornea or nystagmus, a reasonable view of the posterior pole may be obtained by using a direct