Dear Editor,

The article by Al-Hazmi et al.[1] states that combined trabeculotomy- trabeculectomy with mitomyocin C (CTTM) gave better results than trabeculotomy alone for primary congenital glaucoma (PCG) at the King Khaled Eye Specialist Hospital (KKESH) in Riyadh, Saudi Arabia, between 1982 and 2002. For moderate PCG the success rate is stated as 40% and 80% for trabeculotomy and CTTM, respectively. For severe PCG the stated success rate is 10% and 70% for trabeculotomy and CTTM, respectively. However, without more specifics regarding when the trabeculotomies were performed at KKESH, the authors cannot advocate CTTM over trabeculotomy for moderate and severe PCG.

As the article states, over the years at KKESH the success rate for trabeculotomy for PCG dramatically improved (29% from 1982-1990; 47% from 1991-94; 82% from 1995-2002) The authors attribute these improved results over the years to improved primary healthcare facilities within the kingdom, earlier referrals, better equipment availability, and surgeons becoming more adapt at surgical intervention. In contrast, CTTM for PCG was first performed at KKESH in 1994 with less of a “learning curve”; the success rate from 1994 -2002 was 72%. The complication rate, however, was higher for CTTM than for trabeculotomy.

Because initial trabeculotomy success for PCG at KKESH has dramatically increased with time, it is important to know how many of the reported trabeculotomy failures for moderate and severe PCG were from the earlier periods of the hospital. This information was not in the manuscript. It may be that trabeculotomy as currently performed at KKESH for moderate and severe PCG has a success rate similar to that of CTTM for the same patient population with less surgical complications.

References

1. Al-Hazmi A, Awad A, Zwaan Z, et al. Correlation between surgical success rate and severity of congenital glaucoma. Br J Ophthalmol 2005;89:449–453.