پاتو فیزیو لوژی گلوکوم اطفالدکتر علی صالحی
Types of Glaucoma • Open-Angle Glaucoma • Angle-Closure Glaucoma • Normal-Tension Glaucoma (NTG) • Congenital Glaucoma • Secondary Glaucoma • Pigmentary Glaucoma • Pseudoexfoliative Glaucoma • Traumatic Glaucoma • Neovascular Glaucoma • Irido Corneal Endothelial Syndrome (ICE)
Congenital Or Infantile Glaucoma • Primary congenital, or infantile, glaucoma is elevated intraocular pressure with onset in the first year of life. • It occurs in about 1 out of 10,000 births and results in blindness in approximately 10% of cases and reduced vision (worse than 20/50) in about half of all cases. • approximately 70% of cases are bilateral.
Although diagnosis is made in only 25% of affected infants at birth, disease onset occurs within the first year of life in more than 80% of cases.
Pediatricglaucomas • Constitute a heterogeneous group of diseases that may result from an intrinsic disease or structural abnormality of the aqueous outflow pathways (primary glaucoma) • Or from abnormalities affecting other regions of the eye (secondary glaucoma). • A variety of systemic abnormalities are also associated with pediatric glaucoma.
Systemic diseases with Glaucoma • Aniridia • Marfan's syndrome • Sturge-Weber syndrome • Neurofibromatosis • Down's syndrome • Steroid therapy, including inhaled steroids for asthma and nasal steroids for allergies .
causes • Genetic (e.g. congenital glaucoma, infantile glaucoma, juvenile glaucoma) • Following cataract surgery (aphakic glaucoma) • Due to ocular inflammation (iritis) • Trauma • Malformations of the eye (Axenfeld-Rieger, aniridia , Peters anomaly) • Diseases which affect the rest of the body (Sturge-Weber Syndrome, Lowe Syndrome, congenital rubella)
Primary congenital glaucoma typically presents in the neonatal or infantile period with the classic triad of epiphora, photophobia, and blepharospasm. • Corneal clouding from microcystic edema can occur, accompanied by gradual enlargement of the corneal diameter. As the edema extends through the corneal stroma, breaks called Haabstriae can occur in Descemet’s membrane.
Clinical Findings • Progressive corneal edema with breaks in Descemet’s membrane (Haabstriae) • Elevated IOP, typically non-sedated between 30 and 40 mmHg • Corneal enlargement
The normal intraocular pressure is lower in infants and young children than adults. • A newborn has an average intraocular pressure of 10-12 mm Hg, increasing to 14 mm Hg by age 7 or 8 years of age. • An asymmetric measurement or an elevated measurement in the presence of other clinical signs helps make the diagnosis of glaucoma.
General Pathology • Primary congenital glaucoma may represent an arrest of the normal development of the anterior chamber. • The iris and ciliary body have an anterior insertion with an open angle. • The trabecular meshwork is present and appears patent, but the trabecular beams are thickenedand the deeper tissues appear compressed.
The disease is more common in males, typically is bilateral, and does not have a racial or geographic preference. • Most cases are sporadic, but there is an autosomalrecessive(AR)inheritance pattern eitherautosomaldominant (AD) for some cases. • (GLC3A locus on chromosome 2p21).
Risk Factors • The only known risk factors are genetic consanguinity and affected siblings. • The risk of congenital glaucoma in the second child is approximately 5%, and the risk increases to 25% with two affected siblings.
Diagnosis • The diagnosis of primary congenital glaucoma can often be made clinically, even without an accurate measurement of intraocular pressure. The hallmark of the disease, however, is an elevated intraocular pressure in the absence of other conditions that can cause glaucoma, such as Axenfeld-Reiger syndrome or aphakia.
. A newborn’s cornea is typically 9.5-10.5 mm in diameter and increases to 10.0-11.5 mm by age 1. • Any diameter above 12.5 mm suggests an abnormality, especially if there is asymmetry between the two eyes.
Differential diagnosis • The differential diagnosis depends on the major presenting symptom. • For the classic triad of epiphora, photophobia, and blepharospasm, the differential diagnosis includes: nasolacrimalduct obstruction • conjunctivitis • corneal abrasion • and uveitis.
For corneal clouding and edema, the differential diagnosis includes : • congenital corneal dystrophies • birth trauma with tears in Descemet’smembrane keratitis • congenital ocular anomalies like sclerocorneaor Petersanomaly or • storage disesases like mucopolysaccharidoses or cystinosis
For corneal enlargement, the differential diagnosis includes : • high axial myopia and megalocornea. • For optic nerve cuppingthe differential diagnosis includes: • physiologic cupping • optic nerve coloboma • optic nerve atrophy • optic nerve hypoplasia • an optic nerve malformation
Prognosis • Glaucoma that presents from 3-12 months of age has a favorable prognosis, with 80-90% of cases achieving good control of intraocular pressure with angle surgery. • The vision loss in children ismultifactorialand does not depend exclusively on the health of the optic nerve.
Affected children can develop significant myopia from axial elongation of the globe, • astigmatism from unequal enlargement of the cornea, corneal scarring • Even dislocation of the lens from excessive anterior segment enlargement. • Correction of the refractive error and aggressive treatment of associated amblyopia and/or strabismus is required to maximize visual outcome.
Visual acuity is worse than 20/50 in at least 50% of cases. • This condition is bilateral in about two-thirds of patients • occurs more frequently in males (65%) than in females (35%).
Pathophysiology • The basic pathologic defect in PCG remains controversial. • Barkanoriginally proposed a Thin, imperforate membrane that covered the anterior chamber angle and blocked aqueous outflow.
By age 1 year, normal corneal diameter is 10-11.5 mm • a diameter greater than 12.5 mm suggests abnormality. • Glaucoma should be suspected in any child with a corneal diameter greater than 13mm.
Medical therapy • Medical therapy for primary congenital glaucoma is typically used as an adjunct to surgery. • Oral carbonic anhydrase inhibitors include acetazolamide(Diamox 10-20 mg/kg/day divided into 3 or 4 doses) and methazolamide (Neptazane 5-10 mg/kg QID). • Side affects include weight loss, lethargy, and metabolic acidosis.
Topical carbonic anhydrase inhibitors include dorzolamide 2% (Trusopt) and brinzolamde 1% (Azopt) drops TID. • These medications may produce less reduction in intraocular pressure than oral carbonic anhydrase inhibitors, but also appear to have fewer systemic side affects.
Beta-blockers (timolol or equivalent) can also be given topically, usually using a lower starting concentration of 0.25% drops BID. Side affects include: • respiratory distress, caused by apnea or bronchospasm, and bradycardia.
A combined beta-blocker/carbonic anhydrase inhibitor (Cosopt) drop BID has been shown to be effective in reducing intraocular pressure in children requiring more than one topical medication.
Prostaglandin analogs latanoprost 0.005% (Xalatan), travoprost 0.004% (Travatan), and bimatoprost 0.03% (Lumigan) have been effective in reducing intraocular pressure, although use is discouraged in the presence of inflammatory condition
Miotic agents (pilocarpine, echothiophate) and adrenergic agents (epinephrine, dipivefrin) are not usually effective. • The alpha2-adrenergic agonist brimonidine (Alphagan) is contraindicated in children under age 2 because of potentially serious lethargy, hypotonia, hypothermia, and CNS depression.
Medical follow up • Primary congenital glaucoma requires lifelong serial measurements of intraocular pressure, corneal diameter, refractive error, and optic nerve cupping. • Any change in medical regimen should be followed in 1-2 weeks to assess the efficacy of the new treatment regimen.
Surgical follow up • In the short term, these patients require frequent follow up to monitor for infection or excessive inflammation. Long term, just like patients on medical therapy, these patients require serial measurements of intraocular pressure, corneal diameter, refractive error, and optic nerve cupping. If an adequate assessment of the clinical response is not possible in the outpatient clinic, an examination under anesthesia can be performed.
Complications • The most common complication after surgery is poor control of intraocular pressure. • The success rate for angle surgery is approximately 80% after 1 or 2 procedures, while the other procedures report a success rate of 33-80%.
خداوند در سوره بقره آیه 274 به ستایش کسانی پرداخته که در شب و روز و نهان و آشکار انفاق می کنند و برخی آن را «آیه انفاق» گفته .اند «الذین ینفقون اموالهم بالیل والنهار سرا وعلانیه فلهم اجرهم عند ربهم ولاخوف علیهم و لاهم یحزنون کسانی که دارایی های خود را در شب و روز، و نهان و آشکارا، انفاق می کنند، پاداش آنان نزد پروردگارشان برای آنان خواهد بود، و نه بیمی بر آنان است و نه اندوهگین می شوند».
در آیه 261 سوره بقره می فرماید «مَّثَلُ الَّذِینَ یُنفِقُونَ أَمْوَلَهُمْ فى سبِیلِ اللَّهِ كَمَثَلِ حَبَّةٍ أَنبَتَت سبْعَ سنَابِلَ فى كلِّ سنبُلَةٍ مِّائَةُ حَبَّةٍ وَ اللَّهُ یُضعِف لِمَن یَشاءُ وَ اللَّهُ وَسِعٌ عَلِیمٌ؛ كسانى كه اموال خود را در راه خدا انفاق مى كنند، همانند بذرى هستند كه هفت خوشه برویاند، كه در هر خوشه، یكصد دانه باشد، و خداوند آن را براى هر كس بخواهد (و شایستگى داشته باشد)، دو یا چند برابر مى كند، و خدا (از نظر قدرت و رحمت) وسیع، و (به همه چیز) داناست» (بقره ، 261).