Diode laser treatment of posterior retinopathy of prematurity

AIMS—To study the efficacy of infrared diode laser for the treatment of posterior retinopathy of prematurity (ROP).
METHODS—48 eyes of 25 premature babies (mean birth weight 779 (SD 127.7) g; mean gestational age 25.5 (SD 1.47) weeks) with threshold ROP in zone I and posterior zone II were treated by the indirect infrared (810 nm) diode laser. Confluent burns were applied to the avascular retina. In 18 eyes, an additional row of laser burns was added posterior to the ridge.
RESULTS—Favourable anatomical results were noted in 41 eyes (85.4%). ROP stage 5 developed in two eyes, ROP stage 4A developed in four eyes, and ROP stage 4B in one eye. Three of the eyes with stage 4A eyes were successfully buckled; the fourth was not operated on and remained demarcated by laser scars. No complications were noted.
CONCLUSION—In this series, the diode laser was found to be a safe and effective treatment for posterior ROP.


Correlations Between the Morphology of Sonic Hedgehog Expression Domains and Embryonic Craniofacial Shape

Quantitative analysis of gene expression domains and investigation of relationships between gene expression and developmental and phenotypic outcomes are central to advancing our understanding of the genotype-phenotype map. Gene expression domains typically have smooth but irregular shapes lacking homologous landmarks, making it difficult to analyze shape variation with the tools of landmark-based geometric morphometrics. In addition, 3D image acquisition and processing introduce many artifacts that further exacerbate the problem. To overcome these difficulties, this paper presents a method that combines optical projection tomography scanning, a shape regularization technique and a landmark-free approach to quantify variation in the morphology of Sonic hedgehog expression domains in the frontonasal ectodermal zone (FEZ) of avians and investigate relationships with embryonic craniofacial shape. The model reveals axes in FEZ and embryonic-head morphospaces along which variation exhibits a sharp linear relationship at high statistical significance. The technique should be applicable to analyses of other 3D biological structures that can be modeled as smooth surfaces and have ill-defined shape