23 - Childhood Cataracts and Other Pediatric Lens Disorders Flashcards

Question

# (Infantile nuclear cataract) Concernant l'Infantile nuclear cataract : * Localisation de l'opacité? * Dimensions de l'opcaité? * Densité à la naissance? * Héritée ou Sporadique? * Unilatérale ou Bilatérale? * Stabilité ou Progression de l'opacité? * Autre caractéristique des yeux souvent associée avec les cataractes nucléaires infantiles?

Answer 1

* Nuclear cataracts are opacities that involve the **center, or nucleus**, of the lens. * They are usually approximately **3 mm** in diameter, but the irregularity of the lens fibers can extend more peripherally. * Density and size can vary. * Infantile nuclear cataracts **may not be significantly dense at birth**. * They can be **inherited or sporadic** and are more commonly **bilateral**. * These opacities are **usually stable, but they can progress**. * Eyes with nuclear cataracts may be **smaller than normal**.

Answer 2

* Nuclear cataracts are opacities that involve the **center, or nucleus**, of the lens. * They are usually approximately **3 mm** in diameter, but the irregularity of the lens fibers can extend more peripherally. * Density and size can vary. * Infantile nuclear cataracts **may not be significantly dense at birth**.

Answer 3

* They can be **inherited or sporadic** and are more commonly **bilateral**. * These opacities are **usually stable, but they can progress**.

Answer 4

Eyes with nuclear cataracts may be **smaller than normal**.

Answer 5

Lamellar cataracts or zonular cataracts

Answer 6

Lamellar (zonular) cataracts affect **one or more of the layers of the developing lens cortex** surrounding the nucleus.

Answer 7

* Lamellar (zonular) cataracts affect **one or more of the layers of the developing lens cortex** surrounding the nucleus. * Affected lenses have a **clear center, a discrete lamellar opacity, and a clear peripheral cortex**. * Larger than nuclear cataracts, these opacities are typically **5 mm or more** in diameter.

Answer 8

They can be **unilateral** but are **more often bilateral**.

Answer 9

The size and corneal diameter of affected eyes are **normal**.

Answer 10

Lamellar cataracts are often **less dense than other forms of infantile cataracts**, and therefore the **visual prognosis is usually better**.

Answer 11

* Lamellar (zonular) cataracts affect **one or more of the layers of the developing lens cortex** surrounding the nucleus. * Affected lenses have a **clear center, a discrete lamellar opacity, and a clear peripheral cortex**. * Larger than nuclear cataracts, these opacities are typically **5 mm or more** in diameter. * They can be **unilateral** but are **more often bilateral**. * The size and corneal diameter of affected eyes are **normal**. * Lamellar cataracts are often **less dense than other forms of infantile cataracts**, and therefore the **visual prognosis is usually better**.

Answer 12

* Posterior lenticonus is a cone- shaped deformation of the posterior lens surface caused by progressive thinning of the central capsule * When the deformation is spherical, it is referred to as lentiglobus

Answer 13

* This thinning initially causes the lens to have an “**oil droplet**” appearance on red reflex examination. * As the outpouching of the lens progresses, the **surrounding cortical fibers gradually opacify** (Fig 23-4B). * This process can take many years, but if the **capsule develops a small tear, rapid, total opacification of the lens** can occur (Fig 23-4C).

Answer 14

* The opacities are **almost always unilateral**, and the affected eye is normal in size. * Although the weakness in the **posterior capsule may be congenital**, the cataract **does not usually form until later** and thus behaves like an acquired cataract. * The visual prognosis after cataract surgery is **usually favorable**.

Answer 15

Posterior subcapsular cataracts (PSCs) are **less common in children** than in adults. DONC : adultes >> enfants

Answer 16

* They are usually **acquired** and are often **bilateral**. * PSCs tend to **progress**.

Answer 17

Causes of PSC include * corticosteroid use * uveitis * retinal abnormalities * radiation exposure * trauma

Answer 18

PSCs can be seen in association with neurofibromatosis type 2 and may be the first observed manifestation of this disorder.

Answer 19

**Wedge- shaped** cortical cataracts are occasionally seen in children. These opacities may be **idiopathic**, or they may be associated with * Occult posterior segment tumor * Previous blunt trauma * Vitreoretinopathies * Retinal coloboma with fibrous bands attached to the posterior lens capsule Careful posterior segment examination is indicated to rule out these associated pathologies.

Answer 20

* These asymptomatic peripheral lens vacuoles are sometimes seen in **premature infants**. * The cataracts are most often encountered during examination for **retinopathy of prematurity**. * They are **rarely visually significant** and usually **resolve spontaneously**.

Answer 21

Persistent fetal vasculature (PFV; previously called persistent hyperplastic primary vitreous) is the most common cause of a unilateral cataract.

Answer 22

* Persistent fetal vasculature (PFV) is the most common cause of a unilateral cataract. * PFV is typically an isolated, sporadic ocular malformation, but bilateral cases may be associated with systemic or neurologic abnormalities.

Answer 23

Usually, affected eyes are smaller than normal.

Answer 24

Features of mild PFV are * Prominent hyaloid vessel remnants * A large Mittendorf dot * Bergmeister papilla

Answer 25

At the other end of the spectrum are * Microphthalmic eyes * Dense retrolental plaques * A thick, fibrous persistent hyaloid artery * Elongated ciliary processes (classic for PFV), which may be visible through the dilated pupil * Prominent radial iris vessels

Answer 26

Vrai. Traction on the optic disc may cause distortion of the posterior retina.

Answer 27

* Varying degrees of lens opacification occur. * The opacity usually consists of a **retrolental plaque** that is **densest centrally** and **may contain cartilage and fibrovascular tissue**.

Answer 28

The natural history of more severely affected eyes is usually one of progressive cataract formation and **anterior chamber shallowing, causing secondary glaucoma**. The glaucoma can occur * Acutely because of rapid, total lens opacification and swelling, or * It may develop gradually, over years. Other features of severe PFV : * Congenital retinal nonattachment * Ciliary body detachment * Vitreous hemorrhage * Optic nerve dysmorphism

Answer 29

* **Retinoblastoma** may be part of the initial differential diagnosis of PFV because of leukocoria. * The presence of **microphthalmia** and **cataract** are important factors in the differentiation of these disorders, as retinoblastoma is rarely found in microphthalmic eyes, and cataracts are very unusual in retinoblastoma.

Answer 30

Faux. * In general, **anterior** capsule opacities are **NOT visually significant unless they occlude the entire pupil**. * **Central or posterior** lens opacities of sufficient density that are **greater than 3 mm** in diameter are usually visually significant.

Answer 31

Vrai. Opacities that have a large area of surrounding normal red reflex or that have clear areas within them may allow good visual development.

Answer 32

**Strabismus associated with a unilateral cataract** and **nystagmus associated with bilateral cataracts** indicate that the opacities are visually significant. Although these signs may also indicate that the optimal time for treatment has passed, cataract surgery may still improve visual function.

Answer 33

In preverbal children older than 2 months, standard clinical assessment of **fixation behavior**, **fixation preference**, and **objection to occlusion** provide additional evidence of the visual significance of the cataract(s).

Answer 34

**Preferential looking tests** and **visual evoked potentials** can provide quantitative information.

Answer 35

**In older children**, particularly those with lamellar or posterior subcapsular cataracts, glare testing may be useful for assessing decreased vision.

Answer 36

Vrai. Unilateral cataracts are not usually associated with systemic disease; laboratory tests are therefore NOT warranted in these cases.

Answer 37

* In contrast, **bilateral** cataracts are **associated with many metabolic or other systemic diseases**. * If the child has a **positive family history** of isolated congenital or childhood cataract or if examination of the parents shows lens opacities (and there are **no associated systemic diseases to explain their cataracts**), systemic evaluation and laboratory tests are **NOT necessary**. * A basic laboratory evaluation for bilateral cataracts of **unknown etiology** is outlined in Table 23-3. * Further workup should be directed by the presence of other systemic abnormalities. * Evaluation by a geneticist may be helpful for determining whether there are associated disorders and for counseling the patient’s family regarding recurrence risks.

Answer 38

* In general, **the younger the child, the greater the urgency to remove the cataract**, because of the risk of deprivation amblyopia. * For optimal visual development, a visually significant **unilateral** cataract should be removed **before age 6 weeks**; * Visually significant **bilateral** cataracts, **before age 10 weeks**.

Answer 39

* For older children with bilateral cataracts, surgery is indicated **when the level of visual function interferes with the child’s visual needs**. * Although children with best- corrected visual acuity of roughly 20/70 may function relatively well in early grade school, their participation in activities such as unrestricted driving may be restricted. * Surgery should be **considered** when visual acuity **decreases to 20/40 or worse**. * For older children with **unilateral** cataract, cataract surgery is indicated when visual acuity **cannot be improved beyond 20/40**.

Answer 40

The choice of optical device for correction of aphakia depends primarily on the **age** of the patient and the **laterality** of the cataract.

Answer 41

* Intraocular lens (IOL) implantation in children aged **1–2 years and older** is widely accepted. * The use of IOLs in younger infants, however, is associated with a **higher rate of complications** and **larger shifts in refractive error** with age. * Early surgical intervention followed by consistent contact lens wear and patching of the uninvolved eye usually allows development of some useful vision. * In most infants who are left aphakic, secondary IOL implantation can be performed after 1–2 years of age.

Answer 42

Vrai. In most infants who are left aphakic, secondary IOL implantation can be performed after 1–2 years of age.

Answer 43

Infants with** mild PFV **have a higher incidence of adverse events after lensectomy compared with children with other forms of unilateral cataract, but visual outcomes are similar in both groups.

Answer 44

* To enable access to the lens nucleus and cortex during cataract surgery, a capsulorrhexis is performed. * Because the tearing characteristics of the pediatric capsule are quite different from those of the adult capsule, lens removal techniques are modified for pediatric patients so that the risk of inadvertent extension of the tear is minimized. * The elasticity of the capsule is greatest in younger patients, especially infants, making continuous curvilinear capsulorrhexis more difficult.

Answer 45

In children with dense cataracts that obscure the red reflex, visibility of the anterior capsule can be enhanced with application of **trypan blue ophthalmic solution 0.06%** to the capsule.

Answer 46

Faux. Ultrasonic phacoemulsification is not required, as the lens cortex and nucleus are generally soft in children of all ages.

Answer 47

Removing all cortical material is important because of the propensity for reproliferation of pediatric lens epithelial cells.

Answer 48

* Single- piece foldable acrylic IOLs, which can be placed through a 3-mm clear corneal or scleral tunnel incision, have become popular in pediatric cataract surgery, although larger single- piece polymethyl methacrylate (PMMA) lenses are also still used. * Silicone lenses have not been well studied in children.

Answer 49

* Many pediatric cataract surgeons leave the posterior capsule intact if the child is approaching the age when an Nd:YAG laser capsulotomy in an awake patient could be performed (usually 5 years of age). * Primary capsulectomy is usually preferred for younger children. * Studies have shown that in early childhood, the lens capsule opacifies, on average, within 18–24 months of surgery, but this can vary considerably.

Answer 50

* Studies have shown that in aphakic pediatric eyes, a variable **myopic shift** in refractive error of approximately **7.00–8.00 D occurs from 1 year to 10 years of age**, with a wide standard deviation. * This suggests that if a child is made emmetropic with an IOL at 1 year of age, refractive error at 10 years of age can be –8.00 D or greater. * Refractive change in children younger than 1 year is even more unpredictable.

Answer 51

Lens implantation in children requires consideration of * The **age** of the child * The **target refractive error at the time of surgery** * The **refractive error of the contralateral eye**

Answer 52

**Some surgeons** implant IOLs with powers that are **expected to be required in adulthood**, allowing the child to grow into the selected lens power. * Thus, the child initially requires hyperopic correction. **Other surgeons** aim for **emmetropia at the time of lens implantation** * Especially in **unilateral** cases, believing that this approach improves the treatment of amblyopia and facilitates development of binocular function by decreasing anisometropia in the early childhood years. * These children usually become progressively more myopic and may eventually require a second procedure to address the increasing anisometropia.

Answer 53

* If all cortical material is adequately removed, postoperative inflammation is usually mild in a child without a lens implant. * **Topical antibiotics, corticosteroids, and cycloplegics** are commonly applied for a few weeks after surgery. * **Topical corticosteroids** should be used **more aggressively in children who have under gone IOL implantation**. * Some surgeons administer **intracameral** corticosteroids at the time of surgery, and others use **oral** corticosteroids postoperatively, especially in very young children and in children with **heavily pigmented irides**. * Some surgeons administer **intracameral** antibiotics in addition to topical antibiotics

Answer 54

* For infants with bilateral aphakia, **glasses** are the safest and simplest method of correction. * They can be easily changed according to the refractive shifts that occur with growth of the eye. * **Until the child can use a bifocal lens properly**, the **power selected should make the eye myopic**, because **most of an infant’s visual activity occurs at near**. * Contact lenses may also be used in bilaterally aphakic patients, but they require more effort on the part of both the caregiver and the physician than do glasses.

Answer 55

* For infants with unilateral aphakia, **contact lenses are the most common method of correction**. * Advantages of contact lenses include relatively easy power changes and the potential for extended wear with certain lenses. * Disadvantages include easy displacement by eye rubbing, the expense of replacement, and the risk of microbial keratitis. * Aphakic **glasses** are occasionally used in infants with unilateral aphakia who are unable to tolerate contact lenses, but these glasses are suboptimal owing to the amblyogenic effect of **aniseikonia** and the difficulty of **wearing glasses that are much heavier on one side**.

Answer 56

* After optical correction of aphakia, **patching of the better eye** is necessary in patients with **unilateral cataract** and **in some patients with bilateral cataracts if the visual acuity is asymmetric**. * The amount of patching is based on the degree of amblyopia and the age of the child. * **Avoidance of full- time occlusion** in the neonatal period **may allow stimulation of binocular vision** and **may help prevent strabismus**.

Answer 57

* **Strabismus** is **very common** in children following surgery for either unilateral or bilateral cataracts. * The risk of **glaucoma** is increased in children who have **cataract surgery in infancy** and in those with **small eyes**, but glaucoma often does not develop until several years after surgery. * **Corneal decompensation** is **very rare** in children. * **Retinal detachments** are also **rare** and are most likely to occur when other ocular abnormalities are present. * The incidence of **macular edema** is **unknown**, as it is difficult to detect ophthalmoscopically in young children and optical coherence tomography is usually not possible. * **Postoperative endophthalmitis** **rarely** occurs in children after cataract surgery.

Answer 58

Visual outcome after cataract surgery depends on many factors, including * Age at onset and type of cataract * Timing of surgery * Choice of optical correction * Treatment of amblyopia Optimal vision requires careful, long- term postoperative management, particularly regarding amblyopia. Even when congenital cataracts are detected late (after age 4 months), cataract removal combined with a strong postoperative vision rehabilitation program can achieve good vision in some eyes.

Answer 59

Vrai. Early surgery by itself does not ensure a good outcome.

Answer 60

Green Sunflower Cataract Mx de Wilson

Answer 61

Multicolored flecks (Christmas tree cataract) Hypoparathyroidism Myotonic dystrophy

Answer 62

Antrior polar cataract

Answer 63

Une forme plus sévère de l'anterior polar cataract (APC)

Answer 64

Snowstorm = diabète aigu

Answer 65

Spokelike SCP

Answer 66

Galactosémie

Answer 67

Oil Droplet cataract

Answer 68

Persistent fetal vasculature (PFV) * 1 : The tunical vasculosa lentis surrounds the lens * 2 : Hyaloid vascular system * 3 : Glial sheath of the hyaloid artery *(Bergmeister papilla)* * 4 : Mittendorf's dot = white opacity on the posterior surface of the lens

Answer 69

* Congenital aphakia, the **absence** of the lens at birth, is **rare**. * This condition is usually associated with a markedly abnormal eye.

Answer 70

* A lens that is **spherical and smaller** than normal is termed spherophakic. * This condition is usually **bilateral**. * The lens may **dislocate and prolapse into the anterior chamber**, causing secondary **glaucoma**.

Answer 71

* A lens coloboma involves **flattening or notching of the lens periphery**. * It may be associated with a coloboma of the iris, optic nerve, or retina, all of which are caused by abnormal closure of the embryonic fissure.

Answer 72

The term lens coloboma is a misnomer because the **lens defect is caused by absence or stretching of the zonular fibers in the affected area** (usually **inferonasally**) and is not directly due to abnormal embryonic fissure closure.

Answer 73

Usually inferonasally

Answer 74

In more significant colobomatous defects, lens dislocations may occur **superiorly and temporally**.

Answer 75

* When the lens is not in its normal position, it is said to be **dislocated**. * **Subluxated** (or subluxed) lenses are partly dislocated. * **Luxated** (or luxed), or **ectopic**, lenses are completely detached from the ciliary body; they are free in the posterior chamber, or they have prolapsed into the anterior chamber.

Answer 76

Spontaneous lens dislocation has been reported in * Aniridia * Buphthalmos associated with congenital glaucoma * Congenital megalocornea with zonular weakness

Answer 77

* In simple ectopia lentis, the lens is displaced **superiorly and temporally.** * The condition is usually bilateral and symmetric. * Most commonly, it is inherited as an **autosomal dominant** trait. * Onset can be **at birth or later in life**. * Glaucoma is common in the late- onset type. * Some patients with **heterozygous mutations in FBN1**, which cause **Marfan syndrome**, do not have the systemic findings associated with this syndrome and have only ectopia lentis.

Answer 78

Ectopia lentis et pupillae is a rare **autosomal recessive** condition in which there is **bilateral** displacement of the **pupil**, usually **inferotemporally**, and dislocation of the **lens** in the **opposite direction**. Déplacement pupille : inférotemporal Déplacement lentille : supéronasal

Answer 79

The condition is characterized by * Small, round lenses (microspherophakia); * Miosis; * Poor pupillary dilation with mydriatics.

Answer 80

Ectopia lentis et pupillae **may be the result of a membrane** extending from a posterior origin to attach to the proximal pupil margin

Answer 81

The syndrome consists of abnormalities of the **cardiovascular, musculoskeletal, and ocular systems**.

Answer 82

* It is inherited as an **autosomal dominant** trait, but family history is negative in **15%** of cases. * Marfan syndrome is caused by mutations in **FBN1**, which provides instructions for making the protein fibrillin-1, the major constituent of extracellular microfibrils.

Answer 83

Affected patients are characteristically * Tall * With long limbs (long membres) and fingers (arachnodactyly); * Loose, flexible joints; * Scoliosis; * Chest deformities.

Answer 84

Cardiovascular abnormalities are a source of significant mortality and manifest as * Enlargement of the aortic root * Dilation of the descending aorta * Dissecting aneurysm * Floppy mitral valve.

Answer 85

Faux. The life expectancy of patients with Marfan syndrome is about half that of the normal population.

Answer 86

Ocular abnormalities occur in more than 80% of affected patients, with lens subluxation being the most common.

Answer 87

* In approximately 75% of cases, the lens is **subluxated superiorly**. * Typically, the **zonules** that are visible are **intact and unbroken**. * Examination of the iris usually shows **iridodonesis** and may reveal **transillumination defects near the iris base**. * The pupil is **small and dilates poorly**. * The **corneal curvature** is often **decreased**. * The **axial length is increased**, and affected patients are frequently myopic. * **Retinal detachment** can occur spontaneously, usually in the second and third decades of life.

Answer 88

* Homocystinuria is a **rare autosomal recessive condition**, occurring in approximately 1 in 100,000 births. * The classic form is usually caused by mutations in the gene encoding cystathionine - synthase, which causes homocysteine to accumulate in the plasma and to be excreted in the urine.

Answer 89

* Homocystinuria is a **rare** autosomal recessive condition, occurring in **approximately 1 in 100,000 births**. * The classic form is usually caused by mutations in the gene encoding cystathionine - synthase, which causes homocysteine to accumulate in the plasma and to be excreted in the urine.

Answer 90

* The **skeletal features** are similar to those of Marfan syndrome. * Affected patients are usually tall and have **osteoporosis, scoliosis, and chest deformities**. * CNS abnormalities occur in approximately 50% of patients; **intellectual disability and seizures** are the most common. * **Vascular complications** are common and secondary to **thrombotic disease**, which affects **large or medium- sized arteries and veins** anywhere in the body. * **Hypertension** and **cardiomegaly** are also common. * **Anesthesia** carries a higher risk for patients with homocystinuria because of thromboembolic phenomena; thus, this disorder should be identified before patients undergo general anesthesia.

Answer 91

* The main ocular finding is **lens subluxation**, most frequently **inferiorly**, but the direction of subluxation is not diagnostic. * Subluxation typically begins between the ages of **3 and 10 years**. * The lenses may dislocate into the **anterior chamber**, a finding suggestive of homocystinuria. * The **zonular fibers are frequently broken**, in contrast with those in Marfan syndrome.

Answer 92

* The diagnosis is confirmed by the detection of **disulfides, including homocystine, in the urine**. * Medical management of homocystinuria is directed toward **normalizing the biochemical abnormality**. * **Dietary management** (low- methionine diet and supplemental cysteine) may be attempted. * **Supplementation with the coenzyme pyridoxine (vitamin B6)** diminishes systemic problems in approximately 50% of cases.

Answer 93

Patients with **Weill- Marchesani syndrome** can be thought of as clinical opposites of patients with Marfan syndrome in that the former are characteristically * Short * With brachydactyly * Short limbs.

Answer 94

* Inheritance can be **autosomal dominant or recessive**. * Mutations in the **ADAMTS10 gene** have been identified in patients with this disorder.

Answer 95

* Inheritance can be **autosomal dominant or recessive**. * Mutations in the **ADAMTS10 gene** have been identified in patients with this disorder.

Answer 96

* The lenses are **microspherophakic**. * With time, the lenses may **dislocate into the anterior chamber** and cause **pupillary block glaucoma**. * For this reason, prophylactic laser peripheral iridectomy or lensectomy may be indicated.

Answer 97

* Sulfite oxidase deficiency (molybdenum cofactor deficiency) is a **very rare hereditary disorder** of sulfur metabolism manifested by **severe neurologic disorders and ectopia lentis**. * The enzyme deficiency interferes with conversion of sulfite to sulfate, resulting in **increased excretion of sulfite in the urine**. * The diagnosis can be confirmed by the absence of sulfite oxidase activity in skin fibroblasts. * Neurologic abnormalities include infantile hemiplegia, choreoathetosis, and seizures. * Irreversible brain damage and **death usually occur by 5 years of age**.

Answer 98

* With mild subluxation, the patient may be only **myopic**, and corrected visual function may be good. * More severe dislocation causes **optical distortion**, because the patient is looking through the far periphery of the lens.

23 - Childhood Cataracts and Other Pediatric Lens Disorders Flashcards

(127 cards)