Congenital glaucoma leads to blindness if not treated. The cause is high intraocular pressure due to a malformation of the outflow pathway of the aqueous humor. Early signs may be noticed by parents: large cornea (buphthalmos), loss of reflectivity of the cornea, increased light sensitivity, and in advanced stages: white, blind eyes. In most cases, treatment is surgical. Surgery is challenging and follow-up over lifetime is demanding including amblyopia prevention, regular measurement of intraocular pressure (IOP), and examinations under general anesthesia in babies. If diagnosed early, congenital glaucoma can be successfully treated in 70-80%.
Method of choice for treatment of congenital glaucoma is trabeculotomy (ab externo) with metal probe or recently, with an illuminated catheter over the complete circumference of Schlemm's canal. Goniotomy has been shown to have similar success rates but is dependent upon a clear cornea.
Whether minimal invasive methods can be considered as competitors to trabeculotomy is still under investigation.
This prospective pilot study compares ab-interno trabeculotomy using the Kahook Dual blade (KDB) with standard ab-interno goniotomy in 21 babies with primary congenital glaucoma in each group. Patients' median age was six (KDB) and five months (goniotomy), respectively. Follow-up was at one, three, six, and 12 months postoperatively.
Elhilali and colleagues found a significant reduction of intraocular pressure (IOP) and medication over time. Success (defined as achieving an IOP ≤ 21mmHg with or without medication) was 57% in each group.
The authors conclude that minimal invasive procedures might still play a role in unilateral, mild cases of primary congenital glaucoma with clear cornea.
However, larger prospective clinical trials are needed, whether these ab interno techniques are comparable to ab-externo reference methods.