Related Experiment Video
Updated: Jun 23, 2026
07:45
Assessing Binocular Central Visual Field and Binocular Eye Movements in a Dichoptic Viewing Condition
Published on: July 21, 2020
Ocular advancement in monobloc distraction.
Edmund J Fitzgerald O'Connor1, Damian D Marucci, Nu Owase Jeelani
1London, United Kingdom From The Craniofacial Unit, Great Ormond Street Hospital for Children.
Plastic and Reconstructive Surgery
|May 2, 2009
Summary
Monobloc distraction advances the globe approximately two-fifths the distance of surrounding bone in children with syndromic craniosynostosis. This study quantifies globe movement following this surgical procedure.
Area of Science:
- Craniofacial Surgery
- Pediatric Plastic Surgery
- Ophthalmology
Background:
- Monobloc distraction is a safe and effective treatment for syndromic craniosynostosis, improving function and aesthetics.
- Previous studies quantitatively assessed bony structure movement but not soft tissue (globe) movement.
- This study introduces a method to objectively analyze globe movement post-monobloc distraction.
Purpose of the Study:
- To quantitatively assess globe movement following monobloc distraction surgery.
- To compare globe advancement to the degree of bony movement in patients with syndromic craniosynostosis.
Main Methods:
- Computed tomographic (CT) scans from 10 patients (Pfeiffer's and Crouzon's syndromes) before and after monobloc distraction were analyzed.
- Voxel image-rendering software created 3D reconstructions from CT data.
- Direct measurements quantified preoperative and postoperative differences in bony and globe positions.
Main Results:
- Achieved average osseous distraction of 12.94 mm (upper face) and 14.19 mm (lower face).
- Measured average globe advancement: 5.28 mm (left eye) and 6.33 mm (right eye).
- Globe advancement was approximately 40% of the surrounding bone's advancement.
Conclusions:
- Forward globe movement following monobloc distraction is a newly described phenomenon.
- While no optic nerve compromise was observed, further assessment of functional implications is warranted.
- This objective analysis provides crucial data on soft tissue changes after craniofacial distraction surgery.
Related Concept Videos
01:28Angle Closure Glaucoma: Treatment
Angle-closure glaucoma, or closed-angle glaucoma, is an eye condition where the iris bulges out and blocks the iridocorneal angle, resulting in a buildup of aqueous humor and increased intraocular pressure. Immediate medical attention is necessary due to the sudden onset of symptoms. The treatment for angle-closure glaucoma includes short-term and long-term approaches. Short-term treatment involves using eye drops like pilocarpine to lower intraocular pressure by increasing aqueous humor...
01:16Focusing of Light in the Eye
Light rays enter the eye through the cornea, a transparent dome-shaped tissue that is the eye's outermost layer. The cornea bends or refracts, light rays traveling to the pupil. The shape of the cornea determines how much of the light is bent and whether the image will be focused correctly on the retina at the back of the eye. Once the light has passed through both refraction layers, it converges into a single focal point onto a small area. This is where photoreceptors start transforming...
01:17Accessory Structures of the Eye
Optical perception, or vision, is an extraordinary sense dependent on converting light signals received via the ocular organs. These organs, known as eyes, are securely positioned within the bony cavities of the skull, called orbits. The orbits serve a dual purpose: a protective shield for the ocular globes and a stable attachment point for the soft ocular tissues. The eye's external protective mechanisms include the eyelids, which are edged with lashes that act as a barrier against foreign...
01:25Glaucoma: Overview
Glaucoma is an eye condition characterized by increased intraocular pressure that damages the retina and optic nerve, leading to irreversible blindness if left untreated. The human eye has various components, including the cornea, iris, pupil, lens, and optic nerve. Aqueous humor is secreted by the epithelium of the ciliary body in the posterior chamber and flows through the trabecular meshwork and canal of Schlemm, maintaining normal intraocular pressure. The trabecular meshwork and the canal...
01:27Open Angle Glaucoma: Treatment
In open-angle glaucoma, the iridocorneal angle remains open, but the trabecular meshwork becomes stiff, slowing down the outflow of aqueous humor. This causes a buildup of aqueous humor in the anterior chamber, leading to a sudden increase in intraocular pressure. The treatment for open-angle glaucoma focuses on reducing the elevated intraocular pressure by either decreasing the secretion of aqueous humor or increasing its outflow.
Drugs such as carbonic anhydrase inhibitors, α2- and...
Drugs such as carbonic anhydrase inhibitors, α2- and...
01:20Muscles of the Eye
The muscles of the eye are sophisticated structures that control eye movement and focus, allowing for the precise and rapid adjustments necessary for vision. The human eye is controlled by ten muscles — six extraocular muscles, three intraocular muscles, and one primary eyelid retractor muscle.
Extraocular Muscles
The six extraocular muscles surround the eyeball and control its movements. They are responsible for a wide range of eye motions, including looking up, down, left, right, and rotating...
Extraocular Muscles
The six extraocular muscles surround the eyeball and control its movements. They are responsible for a wide range of eye motions, including looking up, down, left, right, and rotating...