evaluation of the connections and relationships can be best seen using an endolight to illuminate from behind and across the tissues. The light pipe illuminating from behind sometimes casts a shadow and the connections are better defined. This allows the isolation and dissection of the fibrous tissue of the lens capsule. A vitrectomy lens may also be placed on the cornea to help with visualization. In cases with a sector of peripheral RD, one has a choice of leaving the capsule in that sector or dissecting the area of fibrous connection to allow this fibrous tissue and detached retina to separate and fall back. This dissection is safer and more effectively performed using vitreoretinal scissors. For cases with extensive dissection near the retina the pars plicata entry site holds an advantage. However, when using the pars plicata approach great care is needed to avoid cutting the anterior displaced retina or dragging the vitreous base.

The vitreous base in PFV is abnormal and tends to develop dialyses. Therefore, we generally will make sclerotomies larger than our instruments to reduce the traction on the vitreous base. These sclerotomies are made just behind the iris in areas where the retina is fairly anterior, approximately 1.5 mm, and in other areas it is made more posteriorly, approximately 2.5 mm. Using a posterior approach we usually use 3 ports, although 2 ports may be considered using a dual function infusionlight pipe. If required, the lensectomy is started with entry into the central lens using an MVR blade followed by the vitrectomy probe. The lens material is removed with special care not to open the anterior capsule. Early opening of the anterior capsule causes collapse of the anterior chamber because the vitrectomy probe aspirates the anterior chamber fluid while the posterior segment infusion does not adequately balance the aspiration pressure. In order to balance the fluid flow after the anterior capsule is opened, the posterior capsule must be widely opened to allow free access from the posterior segment. After removal of the cortex and nucleus the capsule is removed. The steps are very similar to the anterior segment; however, the access to the peripheral capsule and the retina is easier from the posterior approach.

8.4.1  The Posterior Surgery

The posterior surgery in cases of stalk related detachments without a significant retrolental mass, may be performed without removal of the lens. Simple stalk

related tent shaped detachments can be released by cutting of the stalk. The more complex RD from PFV has the stalk attached to the apex of a RD with minimal connections, and in these cases simple relaxation of the stalk will allow reattachment. The next step in complexity includes a linear attachment along one of the sides of the tent or pyramid shaped detachment. In these cases, removal of the stalk as well as some dissection along the linear attachment is advisable. One must exercise caution, because if the retina is cut it results in an unfavorable outcome and therefore one must temper the aggressiveness of the vitreous approach. Finally, the most complex cases of RDs take on the shape of a retrolental mass, which is usually centered on the stalk with retinal folds radiating on many sides. In this case, the lens is removed and bimanual surgery used to open and release these connections. This surgery is often very similar to retinopathy of prematurity surgery, which is discussed elsewhere in this book.

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9.1  Introduction

Retinoblastoma is the most common ocular cancer in children occurring in 1/15,000 to 20,000 live births, unchanged over many years [1]. Since only infants and children develop retinoblastoma, the birth rate and infant mortality rate of a country are the basis to estimate the number of affected children. India, with the highest birth rate in the world, also has the highest prevalence of retinoblastoma, estimated to be 1,600 new cases each year (Table 9.1). It is in such countries with high numbers of children with retinoblastoma that standardized optimal therapy may be especially valuable. Also, in countries with high numbers of retinoblastoma patients, clinical trials with significant enrollment can be especially important for advancing therapy of a very rare tumor such as retinoblastoma.

Although the potential cure rate and life expectancy of retinoblastoma patients has improved with innovative therapies, their implementation varies tremendously between centers. The inconsistent management of small numbers of cases per center makes comparison of efficacy difficult.

A. Valenzuela

New Orleans, Mississipi, USA e-mail: aa.valenzuela@gmail.com

E. Héon

Departments of Ophthalmology & Visual Science, University of Toronto, Toronto, ON, Canada e-mail: eheon@attglobal.net

H.S.L. Chan

Departments of Pediatrics, Division of Hematology/Oncology, Hospital for Sick Children, University of Toronto, Toronto, ON, Canada

e-mail: hslchan@attglobal.net

B.L. Gallie (*)

Princess Margaret Hospital, University of Toronto,

610 University Avenue, Toronto, ON M5G 2M9, Canada e-mail: gallie@attglobal.net

Clinical trials are an optimal way to advancing the knowledge of effective therapy [2] and formalize treatments into a well thought-out, peer­ -reviewed, documented, and audited plan. Pediatric oncology has been at the forefront in using formal clinical trials to develop and validate novel therapies, so that they may be ultimately formulated into standardized optimal therapies. It is also recognized that children on clinical trials generally have better outcomes than children treated ad hoc. Therefore, both caregivers and patients contribute to advancing treatment and optimizing outcomes by designing and participating in clinical trials.

Because retinoblastoma is a rare condition, clinical trials require international collaboration to achieve significant enrollment, and are often expensive and challenging to initiate and conduct. The success of such trials requires a standardized language surrounding the various steps of management. Clinical Care Good Practice Guidelines and more detailed, locally adaptable, Standard Operating Procedures (SOPs) may capture some of the benefits of clinical trials, without actually expending the huge costs required for international collaboration and the conduct of multicenter trials. Indeed, these may be effective tools to aid the collaboration and participation of diverse multidisciplinary teams from different institutions, including caregivers, patients and parents. Although meaningful advances in treatment outcomes still depend ultimately on clinical trial validation of novel research, standardization of care through Guidelines and SOPs can do much to facilitate prospective and retrospective clinical evaluations. Guidelines for care of children and families affected by retinoblastoma have been published by the Canadian Retinoblastoma Society and are available on the Internet http://pubservices.nrc-cnrc.ca/rp-ps/inDe- tail.jsp?jcode=cjo&lang=eng&vol=44&is=S2.

We describe here, a framework for Retinoblastoma Good Practice Guidelines in the form of a series of SOPs. These SOPs are designed to cover the complexity of the elements of care for patients and families affected by