Sir,

Dr Ghosh et al.1 reported that a significant proportion of patients (24%) undergoing laser retinopexy required further interventions and the unfamiliarity of the trainees towards laser indirect ophthalmoscope had been attributed as the most important factor for retreatment. However, based on the data cited, we found it difficult to concur with authors' conclusion.

Authors had observed that 24 patients (24%) requiring retreatment and a significant proportion of them (13 patients) had inadequate coverage of the retinal break.1 We believed that the technique in delivering laser was not the sole factor in determining the adequacy of laser barrier. The other equally or even more important factor, namely the amount of any subretinal fluid (SRF) associated with the tears during initial presentation, had not been properly addressed in the article. It has been shown that amount of SRF carries significant bearing over the tissue reaction to laser and the overall completeness of the laser barriers.2 Hence, the treatment success of laser indirect ophthalmoscope photocoagulation over slit-lamp-delivered laser system in complicated retinal tears relies on not only wider optical localization advantage but also the usual scleral indentation manoeuvre performed during laser delivery, through which the SRF can be displaced to facilitate laser absorption.2 A proposed causality between surgeons' inexperience with laser technique and the proportion of retreatment without consideration of the patients factor (nature of the retinal breaks) at the same time is sheer.

Unless further information about the characteristics of the retinal tears treated by trainee ophthalmologists can be rendered, it may be difficult to reach authors' conclusion.