Dr. Uma Pradhan*
Department of Pediatrics.*
| Childhood Glaucoma is a very specialized and challenging subject. It requires accurate knowledge, lot of experience and skill to examine, diagnose and to treat a case of Childhood Glaucoma. It should be a joint endeavor of an ophthalmologist and pediatrician, since pediatrician can be of immense help in diagnosing the associated systemic disorder as well as in management.
The objective of management of childhood glaucoma should be to normalize and control intraocular pressure permanently there by preventing loss of visual acuity, and to preserve visual field and ocular integrity and to stimulate the development of stereoscopic vision.
Childhood Glaucoma can be broadly divided into two categories:
|Salient Features of Childhood Glaucoma|
- It is uncommon an average ophthalmologist is likely to see one case per five years
- Early suspicion and diagnosis is important
- Examination needs patience and skill
- Impact on visual development can be extreme
- Early effective therapy significantly improves visual future
|Epidemiology of Congenital Glaucoma|
|By definition if the onset is before the age of 3 years, it is called as congenital glaucoma. It is usually diagnosed by 6-12 months. The incidence is 1 in 30,000 births. It is an autosomal recessive disease with two linkages at chromosomes 2p and 1p. Gene on 2p is CYPIBI. 65% of all cases are male with 70% bilaterality.
In primary childhood glaucoma, developmental anomalies like Iridodysgenesis, Familial Iris Hypoplasia, Aniridia, Anomalous iris vessels, Microcornea, Microspherophakia are present. Glaucoma associated with other congenital anomalies are present.
- Sturge-Weber Syndrome
- Glaucoma is present when upper lid is involved
- Vascular tissue in ciliary body causes hyper secretion of aqueous and abnormal vessels in angle causes obstruction to aqueous flow
- Marfans syndrome and Homocystinuria Ocular complications like pupil block due to dislocated lens cause glaucoma
- Lowe's Syndrome
- Glaucoma is caused by defective development of angle. Diagnosis is complicated by Microphathalmos and corneal haze.
- Chromosomal defects
- Broad thumb syndrome
- Goldenhars sequence with associated Juvenile Glaucoma
- Turner's syndrome
- Rieger's syndrome
|Secondary Glaucoma in Infants|
- Persistent hyperplastic primary vitreous in which shallow AC, swollen lens with hemorrhage in AC is seen
- Retinopathy of prematurity - Rubeosis (abnormal vessels) of angle causes glaucoma
1.Retinoblastoma-forward shift,inflammation and tumour cells in angle.
|Photophobia, epiphora and blepharospasm is a classical triad which leads to the suspicion of congenital glaucoma. Enlargement of the eyeball along with clouding and enlargement of the cornea resembles an ox eye, hence called Buphthalmos, Inability to see could be other presenting symptom. Epiphora due to congenital dacryostenosis which is very common at this age should be differentiated. In congenital dacryostenosis, there is fullness of lachrymal sac, chronic purulent discharge and absence of photophobia. Baby constantly keeps it's eyes closed or when exposed to sunlight. To avoid pain and photophobia children bury their head in the pillow.|
|Sequelae of raised Intraocular Pressure (IOP)|
|Elevated IOP causes enlargement of the eyeball and stretching of tissues. Overall stretch causes progressive myopia. Sclerocorneal stretch causes big cornea with diameter more than 12 mm. Rupture of Descemet's membrane leading to stromal edema, Habb's striae, erosion, ulceration and permanent scarring can occur. Zonular stretch causes subluxation of lens.|
|Examination includes external exam, corneal assessment, refraction, tonometry, slit lamp exam, gonioscopy, funduscopy, fundus photography and ultrasound biometry. Visual filed recording in children is not reliable, non reproducible due to short attention span and poor fixation. Ultrasound biometry is done to measure axial length which is 17.5 to 20 mm at birth and reaches to 22 mm by the age of 1 year.
Corneal opacification and edema in children due to glaucoma needs to be differentiated from other conditions like sclerocornea, dermoid, corneal dystrophy, inflammations, trauma, anterior chamber cleavage syndrome, trisomy, mucopolysaccharidosis etc.
|Intraocular Pressure Measurement|
- Accurate IOP measurement is important but difficult and tricky in pediatric situation.
- Indentation tonometry with schiotz tonometer is not ideal and is influenced by scleral rigidity and corneal curvature.
- Handheld applanation tonometry is ideal in awake and co-operative child.
- When IOP is to be measured under general anesthesia, we have to remember that, IOP should be recorded as soon as the child is quiet i.e., under light anesthesia.
General anesthesia decreases IOP to variable amount where as ketamine increases IOP slightly. Double check with two instruments is advisable Halothane rapidly decreases IOP. Normal IOP in newborn under Halothane anesthesia is 9-10 mm Hg, 21 mm Hg remains useful upper limit.
Gonioscopy with Koeppe 14-16 mm lens and Barken light or hand held microscope can be done to diagnose anomalies of angle of anterior Chamber.
Funduscopy is important to determine optic disc cupping which occurs rapidly in childhood glaucoma. Disc in newborn is pink with small cup and C : D ratio is 0.3. Cup is often round, steep and enlarged in glaucoma. Drawings and photographs are useful for serial documentation. Differential diagnosis of glaucomatous cupping in children is congenital pit, coloboma oblique entry, tilting of disc, familial enlarged cup, physiological large cup.
|Medical line of treatment has limited place and poor response. Lack of compliance and side effects are added difficulties. Medications are used briefly in pre-operative period for clearing the cornea and improving visualization during the surgery.
Beta blockers such as timolol 0.25% or Betaxolol 0.25% may be administered every 12 hours. Prostaglandin analogues like Latanoprost or topical CAI like dorzolamide can be used 12 hourly. Brimonidine should be avoided as it may cause bradycardia, hypotension, apneic in infants.
It is out of scope of this article to discuss surgical procedures in detail. Goniotomy, Trabeculotomy, combined Trabeculotomy with Trabeculectomy are the procedures which are preferred Visco-canalostomy or Visco-trabeculotomy are newer procedures.
Follow up evaluation and longterm follow up and management is of crucial importance.
|How to Cite URL :|
|Pradhan U D.. Available From : http://www.pediatriconcall.com/fordoctor/ Conference_abstracts/report.aspx?reportid=173|