Intraoperative portable handheld and microscope-integrated OCT enhance the pediatric vitreoretinal surgeon's diagnostic abilities during examination under anesthesia and surgery, particularly in children who are challenging to examine preoperatively due to young age or ocular trauma. Improved OCT-guided visualization of vitreoretinal anatomic relationships has the potential to improve surgical safety and efficiency. In retinopathy of prematurity and other pediatric retinal vascular conditions, intraoperative OCT can be critical for distinguishing between retinoschisis and retinal detachment and highlighting abnormalities of the vitreoretinal interface that may contribute to development of tractional retinal detachments. During retinal detachment repair, intraoperative OCT aids identification of subtle retinal breaks, residual subretinal fluid, retained perfluorocarbon, preretinal membranes, and residual hyaloid, among other findings. In macular surgery, intraoperative OCT has demonstrated value in confirming completion or lack thereof of epiretinal and internal limiting membrane peeling and differentiating between lamellar and full-thickness macular holes. OCT-guided subretinal bleb formation and genetic vector delivery are critical to ensuring accurate localization of subretinal gene delivery for inherited retinal degenerations. Research on development of OCT-compatible surgical instruments, real-time three-dimensional volumetric OCT imaging, and integration with intraoperative OCT angiography are anticipated to further increase the utility of intraoperative OCT in pediatric vitreoretinal surgical decision-making.

Integrated intraoperative anterior segment optical coherence tomography is an extremely valuable tool that can be used by corneal surgeons when performing pediatric lamellar corneal transplant surgery. This chapter will demonstrate its use in infants and children with a variety of corneal diseases. These diseases include congenital corneal opacities such as Peters' anomaly (both types I and II), surgical management of limbal dermoids, and its use in selective corneal transplant surgery such as DALK (deep anterior lamellar keratoplasty) or DSEK (Descemet stripping endothelial keratoplasty). These techniques could be used in children with anterior corneal scarring or storage disorders, such as mucopolysaccharidoses, or posterior endothelial disease, such as congenital hereditary endothelial dystrophy or posterior polymorphous dystrophy. This chapter will demonstrate the author's experience using this device during anterior segment corneal surgery.

The advent of integrated intraoperative optical coherence tomography (i2OCT) has opened the door for safer and more complex surgeries in the retina and cornea. However, to limit its use to just two subspecialties within ophthalmology is an opportunity lost for many other subspecialties. Here, we describe the use of i2OCT in oculoplastic surgery. It can be used in cases of severe symblepharon where the cornea is heavily involved, so that the surgeon is aware of the depth of the pannus when trying to remove it. It can also be used when the corneal planes are difficult to identify. In oculoplastic surgery the technology allows for identification of tissue planes when en face visualization is difficult due to developmental abnormalities and repeated surgeries. Our experience reflects some of the many uses of iOCT in ophthalmic surgery, highlighting its added value in surgical precision.

The advent of integrated intraoperative ocular coherence tomography (i2OCT) has opened the door for safer more complex surgeries of the retina and cornea. However, to limit its use to just two subspecialties within ophthalmology is an opportunity lost for many other subspecialties. Here, we describe the use of i2OCT in strabismus surgery. It can be used to identify extraocular muscles, especially in cases of strabismus reoperations, thereby augmenting the surgical technique. Its use to help train strabismus surgery is invaluable, allowing the trainee to understand the depth of the scleral pass during strabismus surgery. The authors describe these scenarios of training and augmenting the surgical technique.

The advent of integrated intraoperative optical coherence tomography (i2OCT) has opened the door for safer and more complex surgeries in the retina and cornea. However, to limit its use to just two subspecialties within ophthalmology is an opportunity lost for many other subspecialties. Here, we describe the use of i2OCT in pediatric cataract surgery in circumstances that are not traditionally considered for i2OCT use. The specific circumstances include: evaluation and treatment of a child following cataract extraction with lens implantation who has failed two attempts at YAG capsulotomy; lysis of post-trauma keratolenticular adhesion in an opaque cornea; surgical removal of secondary lens epithelial cell proliferation after pediatric cataract extraction with lens implantation, and identification of posterior capsular openings and defects. In each case the use of i2OCT allowed the procedure to be completed safely and successfully or informed the surgeon, allowing modification of the surgical decision tree.

The relationship between the anterior vitreous interface and the posterior capsule has received increasing attention in the past decade. The advent of integrated intraoperative optical coherence tomography has allowed a real-time opportunity to grasp this dynamic understanding. Here we describe the normal anatomy of this interface in children and then demonstrate the variation in this interface with different forms of pediatric cataract, namely a posterior plaque and posterior capsular opacity due to abnormal adherence to the vitreous face. The authors describe these changes using meticulous annotation. An understanding of these differences will aid the surgeon in managing pediatric cataracts in a more confident and safe manner.

The advent of integrated intraoperative optical coherence tomography (i2OCT) has opened the door for safer and more complex surgeries in the retina and cornea. However, to limit its use to just two subspecialties within ophthalmology is an opportunity lost for many other subspecialties. Here, we describe the use of i2OCT in pediatric glaucoma surgery. It can be used to identify Schlemm's canal, Barkan's membrane, demonstrate the corneal pathology in Haab's striae, and iris hypoplasia in cases of Axenfeld-Rieger anomaly. It can help identify drainage blebs that are filtering and those that are not, and identify successful drainage tube flushing. It has also been used to identify a ligating suture effect on a drainage tube. We describe these scenarios in relation to training and augmenting surgical techniques.

Pediatric glaucoma surgery is challenging because of the differences in anatomy from the adult, differences in the behavior of the tissues of a child's glaucomatous eye, the variety in causes of the disease, and difficulties with postoperative management. Goniotomy and trabeculotomy are the preferred initial treatments for primary congenital glaucoma. Trabeculectomy with adjunctive mitomycin C is more likely to succeed in older, phakic patients, but carries the long-term risk of bleb-associated endophthalmitis. Glaucoma drainage devices may be preferred in younger children and in patients with aphakic glaucoma, but these devices can cause tube-related complications. Lastly, cyclodestructive procedures are reserved for patients in whom filtering surgery has failed, given its more unpredictable effects and serious complications.

The coexistence of cataract and glaucoma represents a challenge for the ophthalmologist and the issue is still open to debate. The surgical management is based on both the visual field defect and the loss of visual acuity. The surgical options currently available are: (1) cataract extraction alone, (2) sequential glaucoma surgery and cataract extraction, and (3) combined surgery by 1 site or by 2 separate sites. Phacoemulsification alone is suggested when glaucoma can be controlled by medication and the visual field defect is moderate and nonprogressive. In case of a refractory glaucoma (3 or more types of medication required) with associated early-stage cataract, phacoemulsification could be postponed until after glaucoma surgery. The cataractogenous effect of the procedure should be considered in this situation. Moreover, cataract extraction performed after a filtering surgery may lead to a reduction of the bleb function. When both glaucoma and cataract are sight impairing, combined surgery is indicated since it allows a greater intraocular pressure decrease than phacoemulsification alone.

Advances in anterior segment imaging modalities have contributed new insights towards a better understanding of the various mechanisms of angle-closure glaucoma (ACG). This development is key to good decision making when confronted with angle-closure patients needing appropriate therapy. Surgical management of ACG remains an integral part of glaucoma patient care. The distinctive anatomy of angle-closure eyes and the few objective lines of evidence to support the effectiveness of the different surgical treatment options present a challenge to glaucoma surgeons.

In primary open-angle glaucoma, the site of greatest resistance to aqueous outflow is thought to be the trabecular meshwork (TM) and inner wall of Schlemm's canal. Augmentation of the conventional (trabecular) outflow pathway can facilitate physiologic outflow and subsequently lower intraocular pressure. The most recent approach to enhancing the conventional outflow pathway is via an internal approach to the TM and Schlemm's canal. Ab interno Schlemm's canal surgery includes 4 novel surgical approaches: (1) removal of the TM and inner wall of Schlemm's canal by an internal approach (ab interno trabeculectomy), (2) implantation of a microstent to bypass the TM, (3) disruption of the TM and inner wall of Schlemm's canal via an internal approach (ab interno trabeculotomy), and (4) dilation of Schlemm's canal via an internal approach (ab interno canaloplasty). The first category includes the Trabectome (Neomedix, Tustin, CA, USA), and Kahook Dual Blade (New World Medical, Rancho Cucamonga, CA, USA). The second category includes the iStent (Glaukos, Laguna Hills, CA, USA), as well as the investigational Hydrus Microstent implant (Ivantis, Irvine, CA, USA). The third category includes gonioscopic-assisted transluminal trabeculotomy (iSciences catheter; Ellex, Adelaide, Australia), and 360° suture trabeculotomy (TRAB360, Sight Sciences, Menlo Park, CA, USA). The fourth category includes ab interno canaloplasty or AbiC (Ellex), and Visco360 (Sight Sciences). In contrast to external filtration surgeries, such as trabeculectomy and aqueous tube shunt, these procedures are categorized as internal filtration surgeries and are performed from an internal approach via gonioscopic guidance. Published results suggest that these surgical procedures are both safe and efficacious for the treatment of open-angle glaucoma.

Ab externo Schlemm's canal (SC) surgery (e.g., viscocanalostomy and canaloplasty) is a valuable alternative to glaucoma filtration surgery. It targets the abnormally high resistance to outflow in the trabecular meshwork (TM) and reestablishes the physiologic outflow system. In viscocanalostomy, viscoelastic substance is injected to dilate SC, which in turn leads to microdisruptions of the inner wall. In canaloplasty, the additional intracanalicular stent (suture or Stegmann Canal Expander®) keeps the canal patent and enhances the circumferential flow. A prerequisite for these procedures to work is the integrity of the distal outflow system, which can be evaluated by 2 clinical tests before surgery: provocative gonioscopy with blood reflux, and fluorescein channelography. Ab externo SC surgery is suitable for open-angle glaucoma, but also for angle closure glaucoma in combination with cataract extraction. Intraocular pressure reduction to the mid-teens for viscocanalostomy and to the lower-teens for canaloplasty can be expected. The majority of complications seen in filtering surgery are largely eliminated by the nonpenetrating and bleb-independent approach. Postoperative care is minimal as no bleb management such as needling is required, and hypotony-related complications are largely avoided by the intrinsic resistance of the physiologic outflow system. With its efficacy and high safety profile, ab externo SC surgery will continue to play an increasing role and will change the current concept of glaucoma surgery towards earlier intervention. Surgeons will be well advised to implement these antimetabolite-free procedures into their armamentarium to meet the expectations of the demanding glaucoma patient.