Heather Baldwin

The first part of this review article aims to provide important basic definitions of growth factor terminology, and to put forward a model for understanding the role of growth factors in a wound healing context. In the second part of the paper, we review the literature on growth factors in the cornea, including that on changes associated with wound healing following refractive surgery in the epithelial, stromal, and endothelial layers. The role of growth factors in stromal removal, corneal neovascularization, corneal innervation and wound healing is considered. The importance of the epithelial-stromal interaction is discussed, including the role of growth factors in keratocyte apoptosis. In the final section, we review the current literature on endogenous and exogenous modulation of growth factors in corneal wound healing. This includes important in vitro work but aims to emphasize clinically relevant results. Photorefractive keratectomy (PRK) may have short-term complications such as pain and haze, whereas laser in situ keratomilieusis (LASIK) may have longer-term adverse effects on corneal biomechanics. The emerging technique of laser epithelial keratomilieusis (LASEK) provides an interesting alternative wound which may be less susceptible to the inherent complications of PRK and LASIK. At present, the phenomenon of iatrogenic keratectasia following LASIK is not fully understood, but these features of wound healing following PRK may be amenable to growth factor modulation.

PURPOSE: To assess the efficacy of Müller muscle-conjunctival resection in patients in whom the phenylephrine test was negative. METHODS: A non-randomized, prospective clinical trial was conducted on 20 eyelids of 15 consecutive patients with blepharoptosis who showed no change in the upper eyelid margin-reflex distance (MRD1) following instillation of topical phenylephrine. The technique used was open sky Müller muscle-conjunctival resection. RESULTS: The mean MRD1 increased by 3.3 mm. No patient required augmentation of the procedure, and all patients had excellent appearance of their skin crease and eyelid contour. No complications arose from the procedure, including no incidence of dry eye symptoms or signs. CONCLUSIONS: Müller muscle-conjunctival resection may offer a safe and effective means of treating blepharoptosis despite a negative phenylephrine test.

PURPOSE: To identify and summarize the available published literature describing histologic features of congenital blepharoptosis and to consider the evidence for its classification as either a dystrophy or a dysgenesis. A brief overview of etiologic factors is included to highlight the controversy surrounding the cause of the condition. METHODS: Online searches of the current medical literature were performed with the use of search engines provided in British University libraries. Keywords used were ptosis, blepharoptosis, and birth defect, combined with eyelid. Manuscript copies were obtained and translated where necessary. RESULTS: A summary of data found in more than 35 published papers, including theories of etiology (muscular versus neural, genetic versus sporadic, and environmental factors) and evidence for the classification of congenital blepharoptosis as a dysgenesis and as a dystrophy. Study design and data interpretation are commented on where appropriate. CONCLUSIONS: The scarcity of both affected tissue and normal fetal tissue for histologic examination has limited the understanding of the development and classification of congenital blepharoptosis. Each study analyzed had small specimen numbers, highlighting the need for a review of all available data. The available histologic data appear to support the classification of congenital blepharoptosis as a dysgenesis rather than a dystrophy. It is predicted that a greater understanding of the etiology and histology of this condition may distinguish further subtypes. It is also anticipated that a greater understanding of this condition will allow developments in preventive and therapeutic approaches.