Everyone with neurofibromatosis (NF); NF1, and NF2, should see a neuro-ophthalmologist who is familiar with NF yearly for optic neurological issues that can develop.
A neuro-ophthalmologist is a physician (neurologist or ophthalmologist), specializing in diseases affecting vision that originate from the nervous system. It is not that an ophthalmologist would not be familiar enough with some of the neurological issues that are a result of NF, but tests that need to be done and reviewed require seeing a Neuro-Ophthalmologist, including but not limited to the review of actual MRI scans.
What to bring for eye exam:
The NF condition is rare; the rare condition includes tumors and rare eye problems. The eye problems are uncommon enough that twenty-percent (20%) of vision loss of individuals with NF2 with a diagnosis of ocular abnormalities. Also, some eye abnormalities including juvenile cataracts are used as a part of the NF2 diagnosis criteria to diagnose individuals early.
Common eye problems individuals with NF2 may face include:
While individuals with NF2 can potentially develop age-related cataracts like any other person, there is a high risk of juvenile cataracts. When age-related cataracts develop in people in general, it would develop by 65 years of age but can develop in individuals as young as 40. However, individuals who have NF2 and develop Juvenile Cataracts, it is a Secondary Form of Cataracts that can develop at birth, or would develop well before 65 years.
The formation of NF2 cataracts is typically PSC cataracts, posterior subcapsular lens opacities, which can cause complications in surgical treatment. Individuals with NF2 sometimes develop CC cataracts.
Juvenile Cataracts can result in visual impairments including; blurry vision, poor vision at night, severe reactions to glare, as well as a visibly cloudy or white spot that can be seen covering the eye.
Posterior subcapsular/capsular cataracts (PSC Cataracts) is a form of Cataract that forms behind the Iris and Lenses in the Posterior Chamber.
PSC visual disturbance is a halo effect or glare around lights.
Cortical cataracts (CC), peripheral Cortical Lens Opacities or simply Cortical Opacities, is a form of Cataracts that occurs just behind the Cornea inside the Anterior Chamber of the eye.
CC visual disturbance that would result from this include; peripheral vision (outer vision) issues, at the edges of the lens of the eye as well as blurred vision, glare, contrast, and depth perception issues.
Surgical options are available for both Cataract forms, typically requires artificial lens "intraocular lens" implantation at the time of cataract surgery to replace the damaged natural lens also known as "crystalline lens." Following Cataract surgery glasses will likely be needed, Following Cataract surgery glasses will likely be needed, or will require a change in prescription.
Retinal Detachment is a possible issue, following cataract surgery. In prevention of complications that could result in permanent blindness, quick response following symptoms of retinal detachment is important. Make certain the surgeon is trained in and has treated people with PSC cataracts in the past.
In addition to age, other factors may increase the risk of cataract development. These include; diabetes, smoking, overexposure to sunlight, and certain medications, such as steroids."
Radiation Treatments- Cataracts are common side effects of total body radiation treatments.http://umm.edu/health/medical/reports/articles/cataracts
Retinal detachment (retinal tear) is the result of a weak or thin retina which detaches leaving a break in the retinal thereby allowing fluid to pass under the retina. Following this, the retina peels away from the back of the eye. With this issue, the retina separates from the underlying tissue resulting in vision loss and blindness.
Retinal Detachment is typically the result of Cataract surgery weeks or months later, but can also be Spontaneous as well.
Warning signs include flashing lights, floaters, or blind spots.
Surgical options are possible to correct this if done within twenty-four hours (24-hours) after detachment occurs.
There are 12 pairs of nerves in the central nervous system, a left and a right nerve for each nerve type. Some control muscles and others control senses. The visual processing center of the brain is the occipital lobe with different areas of the lobe affecting different areas in the visual field.
Four Cranial Nerve pairs control the eyes themselves, including; the Optic Nerve, the Oculomotor Nerve, the Trochlear Nerve and the Abducens Nerve.
CNII (Cranial Nerve 2), carries Vision to the brain. This nerve does not contain Schwann cells.
CN3, (Cranial Nerve 3) has two functions it controls:
CN IV (Cranial Nerve 4), controls eyeball movement, rotating, up, down, left and right.
Lateral Rectus Muscle: lateral vision - left to right
Papilledema is swelling of the optic disc (the optic nerve head on the retina) that may cause different intervals of loss and regaining vision, which can become permanent if the cause remains untreated. It can be seen in an eye exam as the pressure behind the eyes in an eye exam and is typically the result of intracranial pressure (obstructive hydrocephalus) from tumor masses in the brain bilaterally (left and right), resulting in pressure on both eyes. It is possible for intracranial pressure to occur on only one side. Left untreated papilledema can result in permanent blindness, or worse.
Symptoms: This can be found in an eye exam sometimes before vision loss occurs. Other symptoms include unexplained nausea, straining, coughing, bending, or ocular migraines. Symptoms may also be worse when changing position including movement from either resting flat to sitting or standing after sitting. A slower change of position will help minimize dizziness and visual disturbances.
Diagnostic Tests: Diagnosis of papilledema requires; 1) a brain MRI, 2) fluorescein angiography to show the grade of papilledema, and 3) visual field test for points of missing vision in eyes. Papilledema can lead to permanent blindness as well as RPE pigmentary changes.
Management: Different treatments may be necessary but managed initially with prescription medication. It is also possible that the papilledema could have been the result of other medications taken and corrected with dose change.
Neurofibromatosis Type 2 (NF2) can easily result in different forms of headache types, superficially two different migraine types including; 1) vestibular migraines, and 2) ocular migraines. Contact doctors on the first occurrence of either type. Both migraine types are signs of serious health issues
Symptom: Ocular migraines (retinal migraines) can include a temporary blind spot, temporary blurring of vision, or vision loss is usually bilateral for different periods of time.
Reason: Ocular migraines are a common occurrence with swelling in the brain and papilledema. Not all occurrences of an ocular migraine require medical management, but episodes should be discussed with doctors since it could be a sign of a serious health issue.
Retinitis pigmentosa (RP) is a name used for conditions that can cause retinal degeneration, vision loss. Pigmentosa is a layer of cells in the back wall of the eye necessary to process light and differentiate color for the optic nerve. RP can result in central vision loss that may eventually result in peripheral vision loss. Central vision is a sight in the center view of the eye. Peripheral vision is the outer range of vision.
Other names for RP include; 1) hyperpigmentation RPE; 2) hyperpigmentation of the retinal pigment epithelium, 3) pigmented layer of the retina, 4) pigmentum nigrum, or 5) intra-retinal leakage of fluorescein.
Retinal pigment epithelium (RPE) (pigmented layer of the retina) is a layer in the eye that shields the retina from excess incoming light.
Possible Option: (April 2018) First Bionic Eye
A condition called combined hamartoma of the retina and retinal pigment epithelium (CHRRPE or CHRPE), is when glial tissue in different parts of the eye. CHRPE causes blood vessels issues and pigment epithelium, resulting in profound vision loss.
Combined hamartoma of the retina and the retinal pigment epithelium is a rare benign lesion in the macula. Juxtapapillary on peripheral location is common in children and that consists of the glial cells (vascular tissue), and sheets of pigment epithelial cells.
Hamartoma, pigmented benign cell tissue, an excess of normal tissue. Hamartoma of the retina is also known as retinal hamartoma.
Juxtapapillary: choroidal neovascular membrane following optic neuritis.
Retinal microaneurysms are a small aneurysm in retinal capillaries; small amounts of swelling in the wall of blood vessels within the eye that look like small, round, red spots.
Epiretinal membrane is a buildup of scar tissue that covers the retina.
A gel that naturally forms over the lens and pupil of the eye called the "the vitreous" is a result of an immune system response to protect the retina. Scar-like cells make up this gel, are a form of scar tissue that can form over the eye and damage the retina's surface. As it gets thicker if it does not sit as a flat layer, it puckers, and the film causes blurry, distorted vision.
Epiretinal membrane is typically the result of either; 1) posterior vitreous detachment (PVD) or 2) diplopia (double vision).
Synonyms for epiretinal membrane include; 1) macular pucker, 2) cellophane maculopathy, 3) retina wrinkle, 4) surface wrinkling retinopathy, 5) premacular fibrosis, and 6) internal limiting membrane disease.
Dry eyes for individuals with NF2 can be the result of different issues, development of severe dry eyes in individuals with NF2 is most commonly the result of either; 1) poor circulation, 2) damage to cranial nerve 7 (facial nerve), 3) damage to cranial nerve 5 (trigeminal nerve), or 3) tumor-drug treatments.
Many of the tumor suppressor including; Bevacizumab (Avastin™), Lapatinib (Tykerb™) and RAD 001 - Everolimus (Afinitor™). These medications can cause dry eye issues and require excessive individuals to drink more water to compensate.
Dry eye issues a result of Avastin, typically only results for the first three (3) months of treatment. When the dry eye is the result of medication, dry eye issues usually stop with breaks or when discontinuing the medication.
If dry eyes are an issue, it could mean that the weakening of either the facial nerve or the result of the trigeminal nerve.
The facial nerve affects the muscles that open and close the eye in addition to producing fluid to keep moisture in the eye. Keeping moisture in the eyes is important to prevent other issues like cracked cornea.
The trigeminal nerve controls the function of the sensation of different parts of the face and some movements of the head; jaw and nasal cavity.
Nystagmus causes ocular flutter. Ocular flutter is a random movement of eyes away from the point of intended focus and often results in reduced vision. If ocular flutter either gets worse, or nothing is done to manage the movement of the eye, it can lead to oscillopsia.
Oscillopsia can be either mild blurring or rapid and periodic jumping of vision. Oscillopsia is a visual disturbance in which objects in the visual field appear to oscillate. The severity of the effect may range from a mild blurring to rapid and periodic jumping. The development of Nystagmus is common for individuals with NF2; it can be the result of the following issues:
Oscillopsia is an incapacitating condition experienced by many patients with neurological disorders.
Diplopia (double vision) is a common issue for people with NF2. Prism glasses might be options to correct these issues if noticed early enough. Depending on the reason for the double vision surgery may be an option.
Temporary diplopia might result in binocular and monocular vision and can be the result of; head trauma, certain medications, alcohol, or eye strain. Temporary Diplopia can result in permanent diplopia.
Binocular diplopia is misalignment with two (2) eyes: both eyes facing in, booth facing out, one eye facing in, or one facing out when seeing double vision.
Binocular diplopia is the result of strabismus. There is two form of strabismus; cross-eye and walleye, binocular diplopia, are different angles of perception and can be the result of eye muscle coordination or a brain issue.
Muscle coordination could be the result of damage to cranial nerves 3, 4, or 6; frequently the result of tumor damage, which can be fixed with surgery to remove the tumor and tightening of the weakened muscles.
Amblyopia is a brain issue that results in one lazy eye that has no vision of perceived vision in the other eye. Cross-eye and walleye treated early can prevent the development of Amblyopia.
Monocular diplopia is damage to an eye that results in the double vision seen with only the damaged eye. Monocular diplopia is the result of damage to the cornea of the eye itself and results in multiple images, seen.
Voluntary diplopia is when an individual has normal eye alignment but can switch to Binocular eye alignment or Binocular eye alignment and can switch to normal eye alignment.
Many issues can result in diplopia, some of which include:
Cornea scars and dry cornea can damage the eye and result in double vision. Dry eyes are a common NF2 issue, and many individuals need to use a constant amount of eye drops.
Juvenile cataracts frequently develop at a very early age for individuals with NF2 and would result in distorted vision.
If the muscle in one of the eyes is weaker than the other, the development of double vision would be the result of the eyes not focusing together.
Eye muscle issues might develop from damage to the facial nerve from of eyelid closure issues.
The third, fourth, and sixth cranial nerves each control different aspects of eye muscle position. Diplopia could be the result of damage to CN3 the oculomotor nerve, CN4 the trochlear nerve or CN6 the abducens nerve.
Management of diplopia can be possible with the following options:
Gaze-evoked tinnitus (GET) is a form of Tinnitus sub-form of a class of tinnitus called somatosensory tinnitus; is affected by either; horizontal, or vertical, not necessarily both. Eye movements affect pitch and tone heard. Eye movements affect pitch and tone heard.
The development of GET is one of the results of damage to hearing. GET can occur after removal of vestibular schwannoma (VS) or acoustic neuroma (AN), which damages cranial nerve 8, associated with the hearing and balance nerves. GET can start after VS damage in one side of the head and seem to be a sound into that ear when the eyes move. When VS damage occurs in both ears, also known as bilateral damage; the sound might be in one or both ears, when the eyes move.
It is unknown exactly why this form of Tinnitus occurs, since it does not always occur after removal of VS, but it is believed to be the result of the brains attempts to find sound.