Retinoscleral control of scleral remodelling in refractive development: a role for endogenous FGF-2?

Cytokine. 2002 Jun 21;18(6):344-8. doi: 10.1006/cyto.2002.1046.


Aims: Studies in avian models of myopia have shown that refractive error development can be influenced by exogenously delivered fibroblast growth factor (FGF)-2. The present study sought to determine whether endogenous FGF-2 was associated with retinoscleral signalling or scleral remodelling during changes in refractive error in a mammalian model of myopia.

Methods: Myopia was induced in tree shrews over a 5-day period. One group of animals was then allowed 3 days of recovery from the induced myopia. Endogenous levels of FGF-2 were measured in scleral and retinal homogenates using ELISA. Real-time PCR was used to investigate scleral FGF-2 and FGF receptor (FGFR)-1 mRNA expression.

Results: No difference in FGF-2 content was found in posterior scleral or retinal extracts of myopic eyes (scleral -4+/-9%, retinal +23+/-17%) or recovering eyes (scleral -10+/-18%, retinal +1+/-13%), when compared with contralateral control eyes. In addition, no significant changes were found in scleral FGF-2 mRNA expression in myopic or recovering eyes (+106+/-56% and +14+/-12% respectively, P=0.21). However, FGF-2 concentration was significantly higher in anterior, relative to posterior, scleral regions in all animals (1602+/-105 vs 1030+/-50pg/mg respectively P<0.001). Expression of scleral FGFR-1 mRNA was upregulated in myopic eyes (+186+/-32%, P=0.01) but returned to control eye levels during recovery (+63+/-20%).

Conclusions: The findings indicate that alterations in endogenous retinal or scleral FGF-2 levels are not associated with changes in scleral remodelling in this mammalian model of myopia. However, the reversible changes found in FGFR-1 expression in the sclera of myopic eyes mean that an indirect role for FGF-2 in the control of scleral remodelling is implicated. The anteroposterior difference found in scleral FGF-2 concentration indicates a role for this cytokine in the control of normal scleral growth and development and, presumably, eye size.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Enzyme-Linked Immunosorbent Assay
  • Fibroblast Growth Factor 2 / metabolism*
  • Fibroblast Growth Factor 2 / physiology*
  • Myopia / metabolism*
  • Myopia / therapy*
  • RNA, Messenger / metabolism
  • Receptor Protein-Tyrosine Kinases / biosynthesis
  • Receptor, Fibroblast Growth Factor, Type 1
  • Receptors, Fibroblast Growth Factor / biosynthesis
  • Retina / physiology
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sclera / metabolism
  • Sclera / pathology*
  • Shrews
  • Time Factors


  • RNA, Messenger
  • Receptors, Fibroblast Growth Factor
  • Fibroblast Growth Factor 2
  • Receptor Protein-Tyrosine Kinases
  • Receptor, Fibroblast Growth Factor, Type 1