Download Tsui, E

Title: Referral for X-linked juvenile retinoschisis (XLRS) leads to unexpected diagnosis
Authors: Eva Tsui, OD
Luisa Prieto, OD
Sherry Bass, OD, FAAO
Presentation Format: Case Report, poster first, paper second
General Topic:
Ocular Disease
Primary Topic:
Posterior Segment
Abstract: X-linked juvenile retinoschisis (XLRS) is a hereditary eye disease that can
result in a cystic macula. Referral to rule out x-linked juvenile retinoschisis can lead to
other “surprise” diagnoses.
I Case History

Patient demographics
18 yo W M

Chief complaint
Referred for ERG/EOG to rule out juvenile retinoschisis. c/o “static and
flashes of colored lights” that occurs all the time

Ocular, medical history
Pt reports seeing “static” for a few years but is currently worsening and is
worst at night. Patient says that it’s hard to focus when waking up to see in the dark.
Patient reports trauma OS when he was 10 years old but never followed up with an eye
doctor. Reports chronic headaches that occur in the back of head that prevents from
sleeping and can be “crippling”. Has had MRI but results were normal. Previously
prescribed glasses to correct for astigmatism but does not wear them.

Medications
None

Other salient information
Wnl health
II Pertinent findings

Clinical
Entering VAs
s specs OD: 20/20-1, OS 20/25;
c specs OD 20/20, OS 20/20-1
Pupils: PERRL(-)APD OU
Extraocular motilities: full and comitant OU
Intraocular pressures: with Goldman tonometry OD 15, OS 14 at 11:16am with
1 gtt Fluress

Physical
Slit lamp
Adnexa: normal OU
Eye lids: mild capped MGs OU, mild crusting inferior to nasal canthus OS
Conjunctiva: white and quiet OU
Cornea: clear OU
Iris: normal OU
Anterior chamber: deep and quiet OU
Lens: clear lens capsule, cortex and nucleus OU
Dilated fundus exam
Vitreous: clear OU
Optic nerve: OD: flat, sharp, good color, large nerve
OS: flat, sharp, good color, oblique insertion, large nerve,
optic disc pit, area of elevation inf-temp to ONH
C/D ratio:
OD: 0.5 H, 0.55 V
OS: 0.55 H, 0.6 V
Macula:
OD: flat, no hemorrhages, exudates, pigmentary changes, or
no macular edema
OS: macular puckering
Retinal vessels: normal OU
Periphery: flat x 360 degrees, no tears, no holes OU
ERG results
Scotopic and phototopic ERG responses are normal OU
III Differential diagnosis

Primary/leading - serous retinopathy secondary to optic pit

Others - Juvenile retinoschisis (XLRS)

Central serous retinopathy
IV Diagnosis and discussion

Elaborate on the condition
Optic disc pit is a rare congenital anomaly of the optic disc that arises in the failure of
the fetal fissure closure in embryogenesis. Incidence is about 1 in 11,000 people, with
no gender preference. The optic disc pits are usually unilateral but can be bilateral.
They are single, oval-shaped depressions most commonly found inferotemporally at the
optic disc. They are usually asymptomatic but can be complicated by maculopathy that
can lead to progressive vision loss. Maculopathy in the form of a serous detachment
occurs in 25-75% of patients with an optic disc pit and usually when it is located
temporally.
X-linked juvenile retinoschisis (XLRS) is a common inherited recessive early-onset
bilateral retinal dystrophy in males. Clinical manifestations of the dystrophy are mildly to
severely reduced central vision arising from foveomacular cavities in the inner retina
and a spoke wheel pattern of retinoschisis in the macular area and associated
peripheral retinoschisis in 50% of patients. Prevalence of this disease is estimated to
be around 1:5000 to 1:28000. The mutation of the XLRS1 gene has been identified as
the main culprit in this dystrophy. The XLRS1 gene codes for the protein retinoschisis
that normally provides adhesion and interaction among cells and the retinal layers.
Defects or absence of the protein secretion reduces the adherence, affecting the
cellular organization and structure of the photoreceptor-bipolar synapse. Abnormal
electroretinograms (ERGs) with marked reduction of the b-wave amplitude and
abnormal b/a ratio have been diagnostic for XLRS.

Expound on unique features
Patient maintains 20/20 vision OS even though he has macular puckering and cystic
changes temporal to the optic nerve head. The cystic changes were unilateral, not
bilateral as is characteristic of juvenile retinoschisis. He also had normal ERG results,
ruling out the possibility of XLRS. OCT images revealed retinal changes that were
cystic, not retinoschisis in nature. No schisis was evident on OCT.
V Treatment, management

Treatment and response to treatment
Monitor. Send back to referring provider. No treatment is indicated at this time.
Patient educated to return to clinic stat if he should experience any changes in his
vision, sudden increase in floaters or flashes of light. It is recommended that patient be
followed with indirect ophthalmoscopy and OCT imaging to monitor changes in cystic
spaces.

Refer to research where appropriate
Optic disc pit maculopathy is characterized by intraretinal and subretinal fluid
at the macula, which can reduce VA to 20/70 or worse. The source of the fluid is unclear
and several theories attribute fluid from the vitreous, cerebrospinal fluid, leakage from
blood vessels at the pit base or choroid. The mechanism of pathogenesis is unclear but
vitreous liquefaction and traction and changes in pressure gradients have been
theorized.
Although spontaneous resolution of the optic disc pit maculopathy is reported
in as many of 25% of case with improvement in vision, treatment for progressive vision
loss is usually indicated. There are no established guidelines for treatment but most
common procedure is pars plana vitrectomy (PPV). The literature supports induction of
complete PVD during a PPV to relieve traction on the optic disc pit. Gas tamponade is
also important to block passage of fluid through the optic disc pit. Perfluoropropane
(C3F8) and sulfur hexafluoride (SF6) gases are both effective. Other successful
interventions have been reported with intravitreal gas injections and macular buckling,
which can be technically challenging. Laser treatment alone is not recommended
because of the significant visual field defects created and is reserved for those that
cannot undergo surgery due to systemic conditions. Other surgical interventions such
as peripaillary laser, ILM peeling, subretinal drainage, peeling of glial tissue and sealing
of the optic disc pit have been controversial. Limited vitrectomy with intraretinal
fenestration is a recent technique with promising results.
VI Conclusion

Clinical pearls, take away points if indicated
The importance of careful clinical observation during a dilated fundus exam is critical
for any patient that sits in your chair. Our patient was a young and healthy male with
excellent central vision and no known family history of ocular issues. He had an
interesting visual disturbance of “static and flashes of colored lights”. This alone
merited a dilated fundus exam to rule out holes or tears in the retina. Upon careful
examination of the patient’s optic nerve, the optic pit and elevated area in the
temporal peripalliary retina revealed itself as an incidental finding. So even before
the ERG testing was done, an important piece of the diagnostic puzzle fell into
place. The subsequent ERG testing confirmed the clinical suspicion, that the patient
did not have juvenile retinoschisis. Furthermore, the OCT imaging revealed that the
separation of the retinal layers were cystic, not true retinoschisis.
References:
Akeo, K., Kameya, S., Gocho, K., Kubota, D., Yamaki, K., and Takahashi, H.; Detailed
morphological changes of foveoschisis in patient with x-linked retinoschisis detected by
SD-OCT and adaptive optics fundus camera; Case Reports in Ophthalmological
Medicine. 2015, article ID 432782.
Gomes da Silveira, C., Soares, G.H., and Provenzano, J. X-linked juvenile retinoschisis;
Rev Bras Oftalmol. 2015; 74(4): 241-3.
Moisseiev, E., Moisseiev, J., and Loewenstein, A. Optic disc pit maculopathy: when and
how to treat? A review of pathogenesis and treatment options. International Journal of
Retina and Vitreous. 2015: 1:13 DOI 10.1186/s40942-015-0013-8
Molday, R.S., Kellner, U., and Weber, B.H.F.; X-linked juvenile retinoschsis: Clinical
diagnosis, genetic analysis, and molecular mechanisms; Progress in Retinal and Eye
Research. 2012; 195-212.
Wang, N.K., Liu, L., Chen, H.M., Tsai, S., Chang, T.C., Tsai, T.H., Yang, C.H., Chao,
A.N., Chen, K.J., Kao, L.Y., Yeung, L., Yeh, L.K., Hwang, Y.S., Wu, W.C., and Lai, C.C.
Clinical presentations of X-linked retinoschisis in Taiwanese patients confirmed with
genetic sequencing; Molecular Vision. 2015; 21:481-501.