Rapid Rehabilitation With Skin-Muscle Sparing Orbital Exenteration: A Single-Center Series.

AIMS: To examine the features and clinical management of patients who underwent skin-muscle sparing orbital exenteration in a tertiary referral center. PATIENTS AND METHOD: Retrospective case-note review for patients undergoing skin-muscle sparing orbital exenteration at Moorfields Eye Hospital between 1997 and 2012. Patient demographics, clinical features, histopathology, clearance, surgery, adjuvant therapy, and outcomes were analyzed. RESULTS: Seventy-four patients (33 male; 45%) had skin-muscle sparing orbital exenteration at a median age of 63.8 years (median 65.5, range 13-96 years) for malignancies primarily arising in the eyelids (34 cases; 46%), orbit (25 cases; 34%) or conjunctiva (15 cases; 20%). The commonest pathologies were sebaceous carcinoma (20 cases; 27%), melanoma (19 cases; 26%), squamous cell carcinoma (12 cases; 16%), and basal cell carcinoma (9 cases; 12%). The patients had very rapid rehabilitation with primary closure of skin-muscle flaps over the cavity, either directly (63/74 patients; 85%), or with addition of local flaps. Local radiotherapy had been given before exenteration to 18 (24%) patients, was administered after exenteration in 19 (26%) patients, and both before and after surgery in 5 (7%); those having postoperative radiotherapy were referred at 2-3 weeks after exenteration, and the initial prosthetics fitting was started at 3-6 weeks after surgery. Thirty-eight (51%) patients died during a follow-up of 1-164 months (mean 55, median 47 months); 20/38 (53%) died from metastases-although 9/20 had known metastatic disease prior to palliative exenteration. Three patients were alive with apparently inactive metastases at 30, 39, and 140 months after surgery. CONCLUSION: Direct closure of skin-and-muscle flaps is achievable in almost all undergoing orbital exenteration. In contrast to skin-grafting, free myocutaneous flaps or secondary intention healing, this allows early referral if adjunctive orbital radiotherapy is needed, and the initial fitting of prosthetics can be within weeks of surgery. The technique also avoids the much greater donor-site morbidity of other reconstructive techniques, such as local or free myocutaneous flaps.

Mutations in SOX2 cause anophthalmia.

A submicroscopic deletion containing SOX2 was identified at the 3q breakpoint in a child with t(3;11)(q26.3;p11.2) associated with bilateral anophthalmia. Subsequent SOX2 mutation analysis identified de novo truncating mutations of SOX2 in 4 of 35 (11%) individuals with anophthalmia. Both eyes were affected in all cases with an identified mutation.

Training and oculoplastics: past, present and future.

PURPOSE: To describe the evolution of ophthalmic plastic surgical training since the establishment of an oculoplastic subspecialty. METHODS: A systematic search and consultation was undertaken, involving various oculoplastic societies and selected members, to better define the previous and currently evolving training paradigms in oculoplastics. The salient events along with variances that exist in programs across the world today are analysed. RESULTS: Oculoplastics emerged as a distillation of expertise from other specialties following World War 2 where a high rate of ophthalmic and oculoplastic trauma had occurred. Following this, learned individuals began aggregating on a regular basis resulting in the formation of dedicated oculoplastic forums, initially in the United States (ASOPRS) and then emerging in Europe (ESOPRS), the UK (BOPSS), South America (SOPANOC), the Far East (APSOPRS), Australia and New Zealand (ANZSOPS), the Middle East and Africa (MEAOPS) and South Africa (SASOPS). More structured and specialist training programmes which were dedicated to clinical and surgical management of adnexal disorders began to develop in parallel. This has resulted in the emergence of specialist adnexal fellowships with regional variation, differences in duration and the opportunity for further subspecialisation. CONCLUSIONS: Oculoplastic surgery has evolved as a highly specific and rapidly growing sub-specialty dedicated to eyelid, lacrimal and orbital care. Its ever increasing popularity has been mirrored by progressively more structured and recognised training programmes globally.

Mutations in BMP4 cause eye, brain, and digit developmental anomalies: overlap between the BMP4 and hedgehog signaling pathways.

Developmental ocular malformations, including anophthalmia-microphthalmia (AM), are heterogeneous disorders with frequent sporadic or non-Mendelian inheritance. Recurrent interstitial deletions of 14q22-q23 have been associated with AM, sometimes with poly/syndactyly and hypopituitarism. We identify two further cases of AM (one with associated pituitary anomalies) with a 14q22-q23 deletion. Using a positional candidate gene approach, we analyzed the BMP4 (Bone Morphogenetic Protein-4) gene and identified a frameshift mutation (c.226del2, p.S76fs104X) that segregated with AM, retinal dystrophy, myopia, brain anomalies, and polydactyly in a family and a nonconservative missense mutation (c.278A-->G, p.E93G) in a highly conserved base in another family. MR imaging and tractography in the c.226del2 proband revealed a primary brain developmental disorder affecting thalamostriatal and callosal pathways, also present in the affected grandmother. Using in situ hybridization in human embryos, we demonstrate expression of BMP4 in optic vesicle, developing retina and lens, pituitary region, and digits strongly supporting BMP4 as a causative gene for AM, pituitary, and poly/syndactyly. Because BMP4 interacts with HH signaling genes in animals, we evaluated gene expression in human embryos and demonstrate cotemporal and cospatial expression of BMP4 and HH signaling genes. We also identified four cases, some of whom had retinal dystrophy, with "low-penetrant" mutations in both BMP4 and HH signaling genes: SHH (Sonic Hedgehog) or PTCH1 (Patched). We propose that BMP4 is a major gene for AM and/or retinal dystrophy and brain anomalies and may be a candidate gene for myopia and poly/syndactyly. Our finding of low-penetrant variants in BMP4 and HH signaling partners is suggestive of an interaction between the two pathways in humans.

Outcome following surgery for contact lens-induced ptosis.

PURPOSE: To assess the outcome of surgery in patients with a history of contact lens wear. DESIGN: Retrospective, comparative interventional case series. METHODS: A total of 419 patients underwent ptosis surgery during a 1-year period (2005-2006) at Moorfields Eye Hospital. Those included in this study had a diagnosis of aponeurotic ptosis and history of contact lens wear. MAIN OUTCOME MEASURES: The outcome was considered a success if the following criteria were met: 1) a margin reflex distance of between 3 and 5 mm, 2) an interlid difference of 1 mm or less, and 3) absence of redo surgery. RESULTS: Thirty patients (7.2%) were identified with a history of contact lens wear and were matched against a control group of 46 patients. The mean margin-reflex distance at presentation was 0.5 ± 2.4 mm. This equated to a ptosis graded as mild (≥1.5 mm) for 32% of patients, moderate (0.5-1.0 mm) for 29%, and severe (≤0.0 mm) for 39%, with similar proportions in the control group (36% mild, 39% moderate, and 25% severe). The power of the refractive correction (p < 0.005) and the age of the patient (p < 0.05) were directly related to increased severity of ptosis at presentation. The surgical outcome of the ptosis correction was successful in 72% of patients, which was significantly lower than in the control group (89%) (p < 0.005). CONCLUSIONS: The severity of contact lens-related ptosis was related to the degree of myopia and the age of the patient but not to the duration of contact lens wear. There was a higher level of failure and requirement for redo surgery in patients with contact lens-related ptosis compared with matched controls.

Seeing clearly: the dominant and recessive nature of FOXE3 in eye developmental anomalies.

FOXE3 is a lens-specific transcription factor with a highly conserved forkhead domain previously implicated in congenital primary aphakia and anterior segment dysgenesis. Here, we identify new recessive FOXE3 mutations causative for microphthalmia, sclerocornea, primary aphakia, and glaucoma in two extended consanguineous families by SNP array genotyping followed by a candidate gene approach. Following an additional screen of 236 subjects with developmental eye anomalies, we report two further novel heterozygous mutations segregating in a dominant fashion in two different families. Although the dominant mutations were penetrant, they gave rise to highly variable phenotypes including iris and chorioretinal colobomas, Peters' anomaly, and isolated cataract (cerulean type and early onset adult nuclear and cortical cataract). Using in situ hybridization in human embryos, we demonstrate expression of FOXE3 restricted to lens tissue, predominantly in the anterior epithelium, suggesting that the extralenticular phenotypes caused by FOXE3 mutations are most likely to be secondary to abnormal lens formation. Our findings suggest that mutations in FOXE3 can give rise to a broad spectrum of eye anomalies, largely, but not exclusively related to lens development, and that both dominant and recessive inheritance patterns can be represented. We suggest including FOXE3 in the diagnostic genetic screening for these anomalies.

Reduced TFAP2A function causes variable optic fissure closure and retinal defects and sensitizes eye development to mutations in other morphogenetic regulators.

Mutations in the transcription factor encoding TFAP2A gene underlie branchio-oculo-facial syndrome (BOFS), a rare dominant disorder characterized by distinctive craniofacial, ocular, ectodermal and renal anomalies. To elucidate the range of ocular phenotypes caused by mutations in TFAP2A, we took three approaches. First, we screened a cohort of 37 highly selected individuals with severe ocular anomalies plus variable defects associated with BOFS for mutations or deletions in TFAP2A. We identified one individual with a de novo TFAP2A four amino acid deletion, a second individual with two non-synonymous variations in an alternative splice isoform TFAP2A2, and a sibling-pair with a paternally inherited whole gene deletion with variable phenotypic expression. Second, we determined that TFAP2A is expressed in the lens, neural retina, nasal process, and epithelial lining of the oral cavity and palatal shelves of human and mouse embryos--sites consistent with the phenotype observed in patients with BOFS. Third, we used zebrafish to examine how partial abrogation of the fish ortholog of TFAP2A affects the penetrance and expressivity of ocular phenotypes due to mutations in genes encoding bmp4 or tcf7l1a. In both cases, we observed synthetic, enhanced ocular phenotypes including coloboma and anophthalmia when tfap2a is knocked down in embryos with bmp4 or tcf7l1a mutations. These results reveal that mutations in TFAP2A are associated with a wide range of eye phenotypes and that hypomorphic tfap2a mutations can increase the risk of developmental defects arising from mutations at other loci.

A surgical strategy for the correction of Fraser syndrome cryptophthalmos.

PURPOSE: To describe a systematic approach for managing the structural adnexal anomalies encountered in Fraser syndrome, a multisystem, autosomal recessive condition associated with cryptophthalmos. DESIGN: Retrospective, noncomparative, interventional case series. PARTICIPANTS: All patients with Fraser syndrome-related cryptophthalmos managed at a Moorfields Eye Hospital during a 23-year period between 1984 and 2007. METHODS: All patients' clinical records were reviewed. The age of the patient at presentation, sex, ethnic origin, parental consanguinity, associated systemic features, length of follow-up, and surgical interventions were recorded. MAIN OUTCOME MEASURES: The sequence of surgical procedures performed for the different morphologic cryptophthalmos subtypes, postoperative visual acuity, and corneal survival. RESULTS: The study includes 13 eyes of 7 patients. Cryptophthalmos was complete in 3 eyes and abortive in 10 eyes; no cases of incomplete cryptophthalmos were encountered in this series. The aim of surgical intervention in the latter was to optimize visual potential. Surgical steps included dissection of corneal adhesions from keratinized cornea, mucous membrane graft, Mustarde eyelid switch flap with subsequent division, and further lower lid augmentation as required (n = 10). For complete cryptophthalmos, surgery was recommended if cosmetic improvement was sought and enough tissue remained after any repair of abortive cryptophthalmos in the fellow eye. Surgery in these cases involved the creation of fornices, with subsequent upper and lower lid reconstruction with local skin/muscle flaps (n = 1). Postoperative acuities ranged from perception of light to 20/200. Good outcomes in terms of corneal health were achieved in 6 of the 10 eyes operated on for incomplete cryptophthalmos. CONCLUSIONS: Although Fraser syndrome is rare, the periocular surgical management of these complex cases may be planned using a systematic approach as described in this study, which is the largest such series to date. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Novel heterozygous OTX2 mutations and whole gene deletions in anophthalmia, microphthalmia and coloboma.

Severe ocular malformations, including anophthalmia-microphthalmia (AM), are responsible for around 25% of severe visual impairment in childhood. Recurrent interstitial deletions of 14q22-23 are associated with AM and a wide range of extra-ocular phenotypes including brain anomalies. The homeobox gene OTX2 is located at 14q22.3 and has recently been identified as mutated in AM patients. Eight human OTX2 mutations have been reported in subjects with severe eye malformations, including AM, and variable developmental delay. We screened a novel AM cohort for mutations and deletions in OTX2, and identified four new mutations in six individuals and two cases of whole gene deletions. Our data suggest that OTX2 mutations and deletions account for 2-3% of AM cases.

Innervation and secretory function of transplanted human submandibular salivary glands.

Free submandibular gland autotransplantation is used to treat absolute tear deficiency. Although disconnected from any peripheral innervation, most transplants show increasing secretion for years. We have evaluated the secretory activity and autonomic innervation of such transplants. Secretory activity of glands in response to parasympatholytics and parasympathomimetics was evaluated by Schirmer's test and Technetium scintigraphy. Submandibular gland tissue specimens taken before and after transplantation were examined histologically. Relative hypersecretion during the first postoperative week suddenly decreased but then slowly increased during the first postoperative year. Hypersecretion was significantly reduced by parasympatholytics while carbachol rapidly increased secretion. Histology of transplanted glandular tissue showed parenchymal atrophy. Cholinesterase-positive nerves were abundant and in a similar distribution to normal with scattered positive ganglion cells. Adrenergic axons were fewer than normal and irregularly distributed. Early hypersecretion may be due to release of neurotransmitters from degenerating terminal axons. This is followed by a period of minimal secretion during which hypersensitivity of acinar cells develops. With spontaneous reinnervation, secretion is accentuated by external sympathetic vasomotor adrenergic drive. This shows that submandibular glands can remain viable despite complete separation from their normal nerve supply and are capable of regaining a substantial secretory activity for years.

Incidence of eyelid basal cell carcinoma in England: 2000-2010.

INTRODUCTION: Basal cell carcinomas (BCCs) are the most frequently diagnosed type of skin cancer, with eyelid (including canthus) BCCs accounting for a notable proportion of these. Using population-based data from the English Cancer Registries, we report here the incidence of eyelid BCCs in England, for the period 2000-2010. METHODS: ICD-10 and histology codes for eyelid BCCs (including canthus) from the English National Cancer Data Repository were used to identify incident events. Crude incidence rates by age and sex, together with directly standardised incidence rates for eyelid BCCs in England in 3-year cohorts, are presented, in keeping with the reporting practice of the English Cancer Registries. RESULTS: Over the 11-year study period, there were a total of 33 610 recorded eyelid BCCs; 18 146 in females and 15 464 in males. There were regional variations in registrations. Incidence of eyelid BCCs increased with age. No major change in the age-standardised incidence of BCC was observed during the period 2000-2010. Overall, the age-standardised incidence of BCCs during 2008-2010 was similar for males and females (4.51 per 100 000 (95% CI 4.37 to 4.65) and 4.53 per 100 000 (95% CI 4.40 to 4.67), respectively). However, females under 50 years of age had higher incidence rates, and males over 75 years of age had higher rates. CONCLUSIONS: The findings provide the current frequency and distribution of eyelid BCCs in England, highlighting opportunities for health education and improving reporting and registration of events, and for informing service planning.

Eyelid reconstruction: the state of the art.

PURPOSE OF REVIEW: The goals of eyelid reconstruction are corneal protection, restoration of the integrity of the lid lamellae, and improvement of facial symmetry. Inadequate reconstruction may lead to corneal exposure and sight-threatening keratopathy; in the younger patient, visual deprivation and amblyopia may also follow. The purpose of this review is to describe new materials and approaches used in reconstructing the damaged eyelid. RECENT FINDINGS: Although the surgical principles of lid reconstruction remain unchallenged, new materials and techniques have emerged. These include the use of both autogenous and cadaveric acellular dermis in the management of lower eyelid retraction, and amniotic membrane transplantation in the management of tarsal conjunctival disease. Recent work on upper facial nerve branch reinnervation in the animal model may also offer hope for eyelid reanimation after facial palsy. SUMMARY: The lid surgeon requires a sound knowledge of the principles involved in reconstructing the respective lamellae of the lid. Anterior lamellar reconstruction carries a significant risk of ectropion, and large defects may require several interposition flaps for optimum skin texture and color reconstruction. New materials (autogenous and cadaveric) for posterior lid reconstruction may reduce donor site morbidity and surgical time, but they may contract significantly after surgery. Recent experience with amniotic membrane transplantation may improve the prognosis for patients with entropion and symblepharon caused by conjunctival cicatricial changes.

Trachomatous trichiasis and its management in endemic countries.

Trichiasis is the sight-threatening consequence of conjunctival scarring in trachoma, the most common infectious cause of blindness worldwide. Trachomatous trichiasis is the result of multiple infections from childhood with Chlamydia trachomatis, which causes recurrent chronic inflammation in the tarsal conjunctiva. This produces conjunctival scarring, entropion, trichiasis, and ultimately blinding corneal opacification. The disease causes painful, usually irreversible sight loss. Over eight million people have trachomatous trichiasis, mostly those living in poor rural communities in 57 endemic countries. The global cost is estimated at US$ 5.3 billion. The WHO recommends surgery as part of the SAFE strategy for controlling the disease.We examine the principles of clinical management, treatment options, and the challenging issues of providing the quantity and quality of surgery that is needed in resource-poor settings.

Kinematic analysis in oculoplastic reconstructive surgery: measuring manual control and fluidity of movement.

OBJECTIVE: To evaluate higher-order kinematic analysis, a technique not previously applied to surgical skills assessment, as a tool for elucidating patterns of movement. METHODS: An observational cohort study of 27 subjects, divided into 3 equal groups based on surgical experience consisting of novice (performed <5 prior procedures), intermediate (performed 5-100 prior procedures), and expert (performed >100 prior procedures) subjects. The subjects placed a deep 3-1-1 suture onto a shielded hook on a standardized surgical skills practice board. Detailed 3-dimensional motion data were obtained using a motion capture system. Two novel parameters were used to analyze movement patterns: the frequency distribution (cumulative histogram), describing the distribution of movement sizes used, and the probability density function (normalization of frequency distribution data), evaluating the distribution of motion against the magnitude of movement. The α risk for statistical significance was set at .05. RESULTS: We found significant differences among the 3 groups for frequency distribution (P = .02; Kruskal-Wallis test) and probability density function (P = .03). CONCLUSIONS: These 2 indices, derived from kinematic analysis, appear to distinguish between groups of test subjects with known differences in surgical experience. The evaluation of higher-order motion patterns appears to be of value in the objective evaluation of surgical skills. This method for assessment of manual skills is likely to provide a better guide as to which patterns of movement have the greatest efficiency for specific tasks.

Early midline interactions are important in mouse optic chiasm formation but are not critical in man: a significant distinction between man and mouse.

The optic chiasm is one of the most popular models for studying axon guidance. Here axons make a key binary decision either to cross the midline to innervate the contralateral hemisphere or to remain uncrossed. In rodents, midline interactions between axons from the two eyes are critical for normal development, as early removal of one eye systematically disrupts hemispheric projections from the remaining eye, increasing the crossed projection at the expense of the uncrossed. This is similar to the abnormal decussation pattern seen in albinos. This pattern is markedly different in marsupials where early eye removal has no impact on projections from the remaining eye. These differences are related to the location of the uncrossed projection through the chiasm. In rodents these axons approach the midline whereas in marsupials they remain segregated laterally. We provide anatomical evidence in man suggesting that, unlike in rodents, uncrossed axons are confined laterally and do not mix in each hemi-chiasm, which is a pattern similar to that found in marsupials. Further, we demonstrate electrophysiologically, using visual cortical evoked potentials, that the failure of one eye to develop in man has no impact on the hemispheric projections from the remaining eye. These data demonstrate that the mechanisms regulating chiasmal development in man differ from those in rodents but may be similar to those in marsupials. We suggest that mouse models of the organization and development of the optic chiasm are not common to placental mammals in general.

SOX2 anophthalmia syndrome.

Heterozygous, de novo, loss-of-function mutations in SOX2 have been shown to cause bilateral anophthalmia. Here we provide a detailed description of the clinical features associated with SOX2 mutations in the five individuals with reported mutations and four newly identified cases (including the first reported SOX2 missense mutation). The SOX2-associated ocular malformations are variable in type, but most often bilateral and severe. Of the nine patients, six had bilateral anophthalmia and two had anophthalmia with contralateral microphthalmia with sclerocornea. The remaining case had anophthalmia with contralateral microphthalmia, posterior cortical cataract and a dysplastic optic disc, and was the only patient to have measurable visual acuity. The relatively consistent extraocular phenotype observed includes: learning disability, seizures, brain malformation, specific motor abnormalities, male genital tract malformations, mild facial dysmorphism, and postnatal growth failure. Identifying SOX2 mutations from large cohorts of patients with structural eye defects has delineated a new, clinically-recognizable, multisystem disorder and has provided important insight into the developmental pathways critical for morphogenesis of the eye, brain, and male genital tract.

Heterozygous mutations of OTX2 cause severe ocular malformations.

Major malformations of the human eye, including microphthalmia and anophthalmia, are examples of phenotypes that recur in families yet often show no clear Mendelian inheritance pattern. Defining loci by mapping is therefore rarely feasible. Using a candidate-gene approach, we have identified heterozygous coding-region changes in the homeobox gene OTX2 in eight families with ocular malformations. The expression pattern of OTX2 in human embryos is consistent with the eye phenotypes observed in the patients, which range from bilateral anophthalmia to retinal defects resembling Leber congenital amaurosis and pigmentary retinopathy. Magnetic resonance imaging scans revealed defects of the optic nerve, optic chiasm, and, in some cases, brain. In two families, the mutations appear to have occurred de novo in severely affected offspring, and, in two other families, the mutations have been inherited from a gonosomal mosaic parent. Data from these four families support a simple model in which OTX2 heterozygous loss-of-function mutations cause ocular malformations. Four additional families display complex inheritance patterns, suggesting that OTX2 mutations alone may not lead to consistent phenotypes. The high incidence of mosaicism and the reduced penetrance have implications for genetic counseling.

Orbitotemporal neurofibromatosis. Clinical features and surgical management.

PURPOSE: To classify the periorbital deformities of adult orbitotemporal neurofibromatosis (NF) and describe new clinical findings, and to recommend guidelines for surgical treatment and management of surgical complications. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Thirty-three patients over age 16 with orbitotemporal NF. METHODS: Retrospective surgical case record and serial photographic review recording the laterality and the severity of periorbital involvement, the presence of complications from previous surgery, the surgical techniques undertaken, and the surgical outcome and complications. MAIN OUTCOME MEASURES: Comparison of preoperative and postoperative level of deformities. RESULTS: New classification of periorbital deformities: (1) brow ptosis, (2) upper lid infiltration with ptosis, (3) lower lid infiltration, (4) lateral canthal disinsertion, and (5) conjunctival and lacrimal gland infiltration. Two patients had bilateral and 31 patients (94%) had unilateral orbitotemporal NF. All patients had upper and 19 patients (58%) had lower lid involvement. Six (18%) patients had significant brow infiltration. Fourteen (42%) patients had a dropped lateral canthus requiring surgical reattachment, 28 (85%) required anterior levator resection for ptosis, and 28 (85%) had lid-debulking surgery. New findings included severe brow infiltration, lacrimal gland involvement, and functional nasolacrimal duct obstruction. Complications from previous surgery included residual ptosis, ptosis overcorrection, poor lid contour, dry eye, corneal exposure, and upper and lower lid entropion/ectropion. CONCLUSIONS: The periorbital appearance and comfort of patients with NF type 1 who have orbitotemporal NF can be significantly improved through oculoplastic surgery.

The surgical management of childhood orbito-temporal neurofibromatosis.

PURPOSE: (1) To describe the natural history, changing manifestations and new signs of orbito-temporal neurofibromatosis (NF) during childhood and puberty. (2) To describe the surgical treatment and recommend guidelines for management of this condition in children compared to adults.Methods. Retrospective case note and serial photographic review. RESULTS: There were 9 patients (5M, 4F) with orbito-temporal NF who were children (<16 years) at the time of first presentation with a minimum of 5 years follow up. All the patients had unilateral periorbital neurofibromatosis with blepharoptosis, orbital enlargement and hypoglobus. All nine patients underwent blepharoptosis surgery. Eight patients underwent neurofibroma debulking (and lid shortening) and lateral canthal reattachment. Three had enucleation of their blind eyes. Seven patients had two or more operations for their orbito-palpebral deformities. New signs included conjunctival and lacrimal gland infiltration with a secondary dry eye. CONCLUSION: Blepharoptosis surgery is indicated if the visual axis is compromised and there is a chance of limiting amblyopia. Definitive surgery for appearance is best delayed until the age of 18 years, or when the disease progression has stabilised, unless there are compelling social reasons for earlier surgery.