Introduction

The baby was a one-day old male baby, delivered via emergency LSCS. It was a full term delivery with birth weight of 2.330kg in Sree Balaji medical college and hospital on 24th September 2019. The delivery was uneventful and the general condition of both mother and baby were stable. Ophthalmologist were called to the NICU for an opinion regarding the bilateral bluish discoloration of the baby’s eyes. On examination of the baby there was bilateral bluish discoloration of the cornea, along with increased corneal diameter. Due to the diffused edema, details of structures posterior to cornea could not be perceived. Under local anesthesia corneal diameter and IOP were measured.

Management of The Baby

The baby was started on a topical beta blocker eye drops and antibiotics. The baby was then referred to a glaucoma specialist with experience in congenital glaucoma treatment. After a thorough examination under anaesthesia, trabeculotomy was performed in the right eye and at a later point in time in the left eye. The baby is on regular follow up with the ophthalmologist and the paediatrician.

Family History

On taking detailed Family history, the grandmother revealed she had a twin delivery and both her daughters (which include the baby’s mother) had similar complaints at birth. They underwent a certain surgical procedure back then which was around 40 days post birth, that on ocular examination appears to be peripheral iridotomy. Most probably by Scheie’s procedure. On examination of the mother, there was a very apparent alternating divergent squint (exotropia), in right eye there is an updrawn pupil, whereas in left eye, a peripheral iridotomy scar is seen in the 7’o clock position. Bedside visual acuity both eyes were >5/60.

Results And Discussion

Primary Congenital Glaucoma

Congenital glaucoma was the most common form of paediatric glaucoma accounting for nearly 38% of all childhood glaucoma’s (Taylor et al., 1999). In India a large scale study calculated the incidence to be 1 in 3300 in Andhra Pradesh.3 Primary congenital glaucoma is rare, with an incidence of 1: 10000 population. It can be classified as

• True Congenital Glaucoma(40%) in which IOP is elevated during intrauterine life;
• Infantile Glaucoma (55%) which manifest prior to age 3 and
• Juvenile Glaucoma which is the least common, in which the IOP rises between 3 and 16 years of age.

PCG is thought to be caused by impaired aqueous outflow due to maldevelopment of the AC angle. The prognosis is dependent on severity and age of onset/ diagnosis; in true congenital glaucoma. The Classical triad of congenital glaucoma includes epiphora, photophobia, and blepharospasm. Characteristically, the patients are male (65%) with bilateral involvement (70%) and diagnosed within the first year of life (80%). Visual loss results from Descemet breaks, corneal oedema, and optic neuropathy, and eventually buphthalmos, and amblyopia. Buphthalmos ia a large eye, that is a result of stretching due to elevated IOP prior to the age of 3 years. The thinned sclera often appears blue due to increased visualization of the underlying uvea. Haab striae are curvilinear healed breaks in descemet membrane, complications include myopia and lens subluxation. We have a very small interval or a window period where these children can be successfully treated. If not, the disease can be potentially blinding (Fung et al., 2013).

The current standard of care involves Medical Therapy (prior to angle surgery) as first line therapy usually in the form of Beta-blocker + pilocarpine. Medical therapy after incisional surgery includes prostaglandin analogue/ beta-blocker as first line and Carbonic anhydrase inhibitor as second. Alpha- agonists are contraindicated in infants due to high risk of central depression. Systemic agents are usually needed only temporarily prior to surgery. Medical therapy provides a temporizing measure to clear the cornea to facilitate examination and surgical intervention. Surgical intervention is the definitive treatment. The first two and the most relevant two surgical procedures devised for PCG are goniotomy and trabeculotomy (Dandona et al., 1998).

Goniotomy creates a route for aqueous drainage through Schlemm’s canal by incision of the trabecular meshwork under direct visualization. The success of goniotomy is thought to be approximately 80% with a single procedure. In India, nearly all patients present with clouding and goniotomy is technically impossible (Sood et al., 2018)

Trabeculotomy on the other hand involves disrupting the tissue between Schlemm’s canal and the anterior chamber using an ab externo approach to create direct communication and in contrast to goniotomy can be done in an eye with corneal opalescence. High success rates ranging from 87% to 92% in cases done before one year of age have been reported (Gupta et al., 2016). After angle surgery, trabeculectomy may be useful. However primary trabeculectomy is not a first-line procedure in congenital glaucoma in view of a higher incidence of complications and lower success rate in normalizing intraocular pressure approximately 50% fail in the initial 5–10 years (Mukkamala et al., 2015).

Surgeons have advocated added trabeculectomy whenever there is incomplete canalization in cases of trabeculotomy with equivocal results. Usually amenable to surgical treatment, good results are possible if the disease is diagnosed and appropriately treated in time. Ninety-eight percent of the PCG require surgical treatment. Addition of antifibrotics further increases the success rates as proven in many Indian studies (Møller, 1977).

Netland and Walton first introduced glaucoma drainage devices GDDs to be used in paediatric glaucoma. Over the years various GDDs have been utilized for intraocular pressure control in children. Refractory paediatric glaucoma remains a challenge. Glaucoma drainage devices appear to be the most predictable and possibly safest procedure to consider after failed conventional angle surgery. Regular follow up and monitoring of IOP, corneal diameter and other parameters is required long term, Amblyopia and refractive error should be managed aggressively.

Genetics of Childhood Glaucoma

The majority of primary congenital glaucoma cases are sporadic but 10% - 40% are familial with frequent association  with consanguinity. In the most familial cases, transmission is autosomal recessive with variable expression and penetrance of 40% - 100%.16 Three loci for PCG have been found GLC3A (2p21), GLC3B (1p36), and GLC3C (14q24.3). Two candidate genes: CYPB1 and LTBP2 have also been implicated. The majority of congenital glaucoma map to GLC3A locus on chromosome 2 (2p21). Several CYP1B1 mutations in various ethnic backgrounds have been implicated in the pathogenesis. Various distinct mutations were identified in the coding region of CYP1B1 in patients of PCG-affected families, of which many mutations are novel in the Indian population. Families linked to these loci display autosomal recessive inheritance pattern. Genetic counselling can be provided to at-risk families that will aid in the prevention of PCG-related blindness.

Conclusion

The paediatric eye has its own inherent difficulties. This combined with the failure to report the symptoms, makes these children the most challenging scenarios that the ophthalmologist may encounter. Careful diagnosis and timely intervention leads to the most promising outcome and gives these children a long morbidity free life.

Author contribution

Pugazharasan M, Aluru Jayakrishna Reddy, Manikandan R S, Arul M encouraged and supervised the findings of this work. All authors discussed the results and contributed to the final manuscript.

References

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Gupta, P.C., Singh, R.R., Pandav, S.S., Ram, J., (2016). Rhexis fixation of intraocular lens in a case of buphthalmos with cataract. Nepalese Journal of Ophthalmology. 12; 8(1):71-3.

https://doi.org/10.3126/nepjoph.v8i1.16140

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https://doi.org/10.3928/01913913-20151014-51

Sood, D., Rathore, A., Sood, I., Singh, G., Sood, N.N., (2018). Long-term outcome of combined trabeculotomy-trabeculectomy by a single surgeon in patients with primary congenital glaucoma. Eye. 32(2):426.

https://doi.org/10.1038/eye.2017.207

Taylor, R.H., Ainsworth, J.R., Evans, A.R., Levin, AV. (1999). The epidemiology of pediatric glaucoma: the Toronto experience. Journal of American Association for Pediatric Ophthalmology and Strabismus. 1; 3(5):308-15.

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