Outcomes of early versus delayed trabeculotomy for primary congenital glaucoma

Abstract

Purpose: In patients with primary congenital glaucoma (PCG), elevated intraocular pressure (IOP) causes abnormal eye growth. This study compared the outcomes of children with PCG who underwent ab externo trabeculotomy (TROC) at age ≤ 6 months (early TROC) and of those who underwent TROC at age > 6 months (delayed TROC).

Methods: Intraocular pressure, horizontal corneal diameter (HCD), central corneal thickness (CCT) and axial length (AL) were compared before TROC and at 1-, 3-, 6- and 12-month follow-up visits between the groups of children who underwent TROC until or after 6 months of age. The ALs of these groups were also compared with the ALs of healthy age-matched eyes examined under the same conditions.

Results: Trabeculotomy was performed in 43 children: 18 (33 eyes) aged 6 months (group 1) and 25 (37 eyes) aged >6 months (group 2); the mean ages were 86.56 ± 53.64 and 504.48 ± 448.14 days, respectively. The mean pre- and 12-month postoperative IOP values were 15.97 ± 4.78/16.62 ± 4.85 and 9.77 ± 2.88/10.93 ± 4.83 mmHg, respectively. Delayed TROC was associated with abnormal AL in 31 (88.6%) out of 37 eyes, while after early TROC, only 13 (41.9%) out of 33 eyes had abnormal AL (chi-square, 8.00; p = 0.03). In multivariable analysis, each 1-mmHg increase in preoperative IOP was associated with a 0.25-mmHg increase at 12 months (p = 0.04). On average, the mean IOP of the delayed TROC group was higher than that of the early TROC group by 3.72 mmHg at postoperative month 12 (95% CI = 0.44-6.99; p = 0.02).

Conclusion: Compared with delayed TROC, early TROC is associated with reduced IOP and substantially reduced incidence of abnormal AL at postoperative month 12.

Keywords: axial length; intraocular pressure; primary congenital glaucoma; trabeculotomy.