Subthreshold transpupillary thermotherapy in Chinese patients with myopic choroidal neovascularization: one- and two-year follow up.

BACKGROUND

To perform a safety and efficacy study of subthreshold transpupillary thermotherapy (TTT) in Chinese patients with choroidal neovascularization (CNV) secondary to pathologic myopia.

METHODS

In a prospective study, patients with subfoveal or juxtafoveal CNV secondary to high myopia underwent subthreholdTTT with fixed treatment and follow-up protocols. From October 2002 to July 2005, 12 and 24 months of follow up were completed for 21 eyes and 13 eyes respectively.

RESULTS

The mean best-corrected visual acuities (BCVA) were maintained at the baseline level at 1 and 2 years. Seventy-two per cent of eyes and 63% of eyes had stable or improved BCVA at 12 and 24 months.Thirty-four per cent and 39% of eyes had a moderate gain in vision (improved by three or more lines) at 12 and 24 months respectively.The average number of subthreshold TTT treatments was 1.7. The major complication of subthresholdTTT included laserrelated low-grade retinal pigment epithelium atrophy in two eyes of young patients with clear lenses. The final VA was significantly associated with pretreated VA (r = 0.614, P = 0.003).The final VA improvement was significantly associated with pretreatment VA in negative correlation (r=-0.731, P = 0.0002, Person correlation test).

CONCLUSIONS

Subthreshold TTT in Chinese patients with pathologic myopia and subfoveal or juxtafoveal CNV generally maintained vision at 1- and 2-year follow up. Using decreased power of subthreshold TTT, especially in the younger patients with a clear lens, is suggested.