Sir,

We thank Guggenheim et al1 for their critical comments on our recently published papers.2, 3 We would like to reply to their comments as follows. Myopia is a multigenetic condition involving several overlapping signalling pathways. Therefore, the effects of lumican (LUM) and muscarinic acetylcholine receptors 1 (CHRM1) in myopia are likely to be different between Taiwanese patients and those from other ethnic origin because of differences in environment and race.4 LUM was initially described as a proteoglycan responsible for the control of collagen fibrillogenesis and interaction. The LUM gene is located at 12q21-23 (MYP3), which is a locus associated with high-grade myopia. However, the association between LUM gene and myopia is controversial. We performed two independent studies to identify the association between myopia and LUM gene. The one published in Eye is actually a study that was completed more than 2 years ago. The paper submission and publication process was long and complicated. After completion of the previous study, we tried to identify the possible functional roles of LUM in the pathogenesis of myopia, for which we performed whole gene sequencing analysis on LUM gene and identified one novel polymorphism. The influence of this newly identified polymorphism on the expression levels of LUM was also studied. Taken together, the single-nucleotide polymorphisms in LUM genes may have multiple effects on the expression level of LUM. We have thoroughly studied and listed the association between LUM and myopia in a manner that is not biased on account of using few patients or only one SNP. We must admit that we made errors in the statement of Hardy–Weinberg equilibrium (HWE). The text in one of our reports reads:5 ‘In the test of HWE, there were departures from HWE for S1 in both the control and high myopia groups (P=0.048 and 0.023, respectively) and for S2 in the control group (P=0.012).’ These values were not P values but were the results of HWEχ2. Consequently, the exact statement of the sentence must be changed to ‘In the test of HWE, there were no departures from HWE for S1 in both the control and high myopia groups (HWEχ2=0.048 and 0.023, respectively) and for S2 in the control group (HWEχ2=0.012). The S3 and S4 polymorphisms were not in HWE.’ We had explained the possible problems about departures from HWE in the fourth paragraph in the text,5 and hoped this could decrease the doubt on genotyping or population stratification. Definitely, we must make painstaking efforts in our future studies.