Knobloch Syndrome

knobloch syndrome is a rare, inherited condition that mainly affects the eyes and the back of the skull. most babies are born with very poor eyesight that becomes obvious early in life. the eyes are usually extremely nearsighted (this is called high myopia). the clear gel inside the eye (the vitreous) and the light-sensing layer at the back of the eye (the retina) are fragile and can break down. this breakdown can lead to retinal detachment, which can cause sudden loss of vision if not treated quickly. many people also have a defect in the skull at the back of the head, sometimes with a bulging sac called an occipital encephalocele. not everyone has all features; there is a lot of variety from person to person. EyeWikiMedlinePlusNCBI

Knobloch syndrome (often shortened to KNO) is a rare, inherited condition that mainly affects the eyes and the back of the skull. Children usually have very high short-sightedness (high myopia) and fragile retinae that can tear and detach. Some people also have a hole or sac at the back of the skull (an occipital defect/encephalocele). It’s usually passed down in an autosomal recessive way (both parents silently carry one faulty copy of the gene). Most cases are caused by changes in COL18A1, the gene for collagen XVIII, a basement-membrane protein important in eye and brain development. MedlinePlusGenetic Rare Diseases CenterEyeWikiOrpha

the condition is autosomal recessive, which means a child gets one non-working copy of the same gene from each parent, and the child becomes affected only when both copies are changed. the best-known gene is COL18A1, which makes collagen XVIII, a protein that helps build and maintain thin support layers (basement membranes) in the eye and brain. changes in this gene can weaken these support layers, making the retina and surrounding eye tissues unstable and causing skull-back abnormalities. EyeWikiPubMed

there is also a very rare “knobloch-like” form caused by changes in ADAMTS18, another gene important for eye structure. a third form has been mapped to a region on chromosome 17 (17q11.2), but the exact gene there has not yet been found. this genetic diversity explains why symptoms can differ between families and even between brothers and sisters in the same family. PubMed+1disorders.eyes.arizona.edu


Types

type 1 (kno1): caused by harmful (pathogenic) changes in COL18A1. this is the most common form. it typically shows the triad of high myopia, vitreoretinal degeneration with retinal detachment, and occipital skull defects (sometimes a true encephalocele). some people may also have developmental or neurological issues, but there is wide variation. PubMed

type 2 (kno2): linked to ADAMTS18 gene changes. eye signs resemble type 1 (severe myopia, retinal problems), but brain imaging may show no major malformations in the limited reports so far. published cases are very few, so our knowledge here is still limited. PubMeddisorders.eyes.arizona.edu

type 3 (kno3): mapped to 17q11.2 (gene not yet identified). families show the same core eye problems and occipital scalp/skull defects. because the exact gene is unknown, genetic testing may be negative even when the clinical picture is classic. PubMed


Causes

important note: knobloch syndrome is genetic. there is one root cause—changes in certain genes (most often COL18A1). the list below explains ways those gene changes happen and how they create disease. these are not 20 separate outside triggers; they are 20 genetic and biological causes/mechanisms within that single genetic story.

  1. biallelic loss-of-function in COL18A1 – both copies of the gene are damaged so collagen xviii is missing or too low. this is the main cause. PubMed

  2. nonsense variants – a “stop” signal appears too early and the protein is cut short and non-functional.

  3. frameshift variants – small insertions/deletions shift the reading frame and ruin the protein.

  4. splice-site variants – errors at the boundaries between gene pieces (exons/introns) make the cell cut and paste the message wrongly.

  5. missense variants in key domains – a single letter change in a crucial region bends the protein the wrong way so it cannot do its job.

  6. large deletions/duplications (cnvs) including COL18A1 – chunks of the gene or nearby areas are missing or doubled, so the instructions are broken.

  7. promoter/regulatory variants – changes in on/off switches lower COL18A1 output below a safe level.

  8. compound heterozygosity – two different harmful variants (one from each parent) combine to cause disease.

  9. homozygosity from consanguinity – parents share ancestry, so a rare family variant gets passed to a child twice. this increases risk in some families but is not a blame issue—just genetics.

  10. faulty endostatin domain – collagen xviii contains endostatin, a piece important for blood-vessel and basement-membrane health. damage here can harm retinal structure and nourishment.

  11. defective basement-membrane scaffolding – weak “under-layment” around the retina and vitreous makes tissues fragile and easier to detach.

  12. abnormal vitreoretinal interface – when the “glue” between vitreous and retina is wrong, traction can build and detach the retina.

  13. early eye development errors – during fetal life, collagen xviii guides eye shape; errors here promote high axial length (severe myopia).

  14. macular development disturbance – poor support around the central retina (macula) can lead to macular atrophy or scarring.

  15. ocular blood-vessel signaling changes – endostatin imbalance may alter tiny retinal vessels and the support cells around them.

  16. lens/zonule weakness – collagen network troubles can loosen lens support, causing lens dislocation or cataract.

  17. dural/skull-base weakness – at the back of the skull, weak membranes and bone interaction contribute to occipital scalp defects/encephalocele.

  18. ADAMTS18 loss-of-function – in rare “type 2,” a different protein needed in the lens/retina is missing or faulty, producing a knobloch-like picture. PubMed

  19. unknown 17q11.2 gene (type 3) – alterations near this region likely affect a still-unknown protein that plays a similar eye/skull-support role. PubMed

  20. modifier genes/background – other small genetic differences may raise or lower severity (why the same main variant can look different between people). current research suggests variability is common. PubMed

Symptoms and signs

  1. very high myopia (severe nearsightedness) – babies/young children need very strong glasses; the eye is longer than usual. core feature. MedlinePlus

  2. vitreoretinal degeneration – the gel inside the eye becomes stringy or forms sheets; the retina looks thin and fragile. EyeWiki

  3. retinal detachment (often recurrent) – sudden curtain over vision, floaters, or flashes; an emergency needing surgery quickly. Genetic Rare Diseases Center

  4. macular changes – central retina can scar or atrophy, reducing sharp vision and reading ability. NCBI

  5. night blindness and reduced dark adaptation – seeing in dim light is hard; this can start early in childhood. disorders.eyes.arizona.edu

  6. nystagmus – eyes make small, shaky movements because the brain is trying to find a clear image. disorders.eyes.arizona.edu

  7. strabismus (eye misalignment) – one eye may turn in/out/up/down; the brain may suppress one image to avoid double vision. disorders.eyes.arizona.edu

  8. cataract or lens dislocation – the lens can become cloudy or shift from its normal position, further reducing vision. disorders.eyes.arizona.edu

  9. glaucoma (sometimes) – pressure damage to the optic nerve can occur in some people with complex eye anatomy. disorders.eyes.arizona.edu

  10. small or unusual optic discs – the “cable head” of the optic nerve can look small or atypical on eye exam. disorders.eyes.arizona.edu

  11. occipital encephalocele or occipital scalp/skull defect – a lump or opening at the back of the head present at birth (may be surgically repaired). MedlinePlus

  12. headaches or signs of raised pressure – if there is a skull defect or fluid issue, headaches, vomiting, or irritability can appear.

  13. seizures or abnormal eeg (some cases) – related to brain structure differences in a subset of patients. PMC

  14. developmental delay or coordination issues (variable) – some children have speech, fine-motor, or balance problems; others develop typically. Thieme

  15. behavioral/learning differences – some reports mention autism-spectrum features or learning challenges, but this is not universal. PubMed


Diagnostic tests

how doctors confirm knobloch syndrome: they combine history, eye and neurological exams, imaging, and genetic testing. because the condition is rare, the safest path is to test the known genes when the eye findings + skull-back features fit the picture.

a) Physical examination

  1. head and scalp check – the doctor gently inspects and palpates the back of the head for a soft bulge, scar, or opening that suggests an occipital encephalocele or scalp defect. this guides the need for brain/skull imaging. MedlinePlus

  2. full neurological exam – checks tone, reflexes, strength, sensation, balance, and coordination to look for problems linked to brain structure differences. PMC

  3. developmental screening – age-based checklists (speech, social, motor, cognition) help flag delays so early therapy can start.

  4. external eye exam – the eye doctor looks for nystagmus, strabismus, lens position, and front-of-eye clarity (cornea, lens) before dilating the pupils. disorders.eyes.arizona.edu

b) Manual (bedside/office) eye tests

  1. visual acuity testing (snellen or logMAR) – measures sharpness of vision with best glasses; monitors change over time.

  2. retinoscopy/autorefraction – objectively measures refractive error to confirm high myopia and set a starting glasses prescription. EyeWiki

  3. confrontation visual fields – quick screen for side-vision loss (can be affected by retinal damage).

  4. color vision testing (e.g., ishihara plates) – checks cone function; can be reduced with macular/retinal disease.

  5. cover–uncover / alternate cover tests – detects strabismus and latent eye drift that may worsen with poor fixation. disorders.eyes.arizona.edu

c) Lab & pathological (molecular) tests

  1. targeted sequencing of COL18A1 – looks for single-letter changes and small insertions/deletions. if negative but suspicion is strong, add deletion/duplication analysis for larger changes. this is the main confirmatory test for type 1. PubMed

  2. ADAMTS18 gene testing – considered when the picture fits knobloch but COL18A1 is negative; can identify type 2 in rare families. PubMed

  3. inherited retinal disease (ird) next-generation panel – a broader panel that includes COL18A1, ADAMTS18, and other eye genes; helpful when diagnosis is uncertain or multiple eye genes are possible. JAMA Network

  4. whole-exome or whole-genome sequencing – captures hard-to-find or novel changes, and may help in families suspected of type 3 where the precise gene is still unknown. PubMed

research-only note: a few studies measured collagen xviii in blood and found low levels, but this is not a standard clinical test today. PubMed

d) Electrodiagnostic tests

  1. full-field electroretinography (erg) – measures electrical responses of rods and cones. patterns can show a cone-rod or generalized retinal dysfunction in knobloch; useful for prognosis and for telling it apart from other retinal diseases. JAMA Network

  2. visual evoked potentials (vep) – checks the signal from the eye to the brain; can be abnormal if macula or optic pathways are affected. JAMA Network

  3. electro-oculography (eog) – assesses retinal pigment epithelium function; sometimes used as a complementary test in inherited retinal conditions. JAMA Network

e) Imaging tests

  1. optical coherence tomography (oct) of the macula and optic nerve – a painless “light ultrasound” that shows thinning, macular atrophy, schisis, or traction at the vitreoretinal interface. this helps decide urgency and treatment. EyeWiki

  2. b-scan ocular ultrasonography – useful when the retina cannot be seen clearly (for example, due to cataract or vitreous haze); quickly detects retinal detachment or abnormal vitreous membranes. Genetic Rare Diseases Center

  3. mri of brain and craniocervical junction – looks for occipital encephalocele, other skull-base defects, and brain malformations; helps neurosurgeons plan care. PMC

  4. ct of skull/occipital bone (when needed) – shows bony defects and the edges of the skull opening with high detail; used judiciously because it involves radiation. MedlinePlus

Non-pharmacological treatments

  1. Regular retina-focused eye follow-up
    Purpose: catch retinal tears/detachments early.
    How it helps: careful dilated exams and imaging allow early laser/cryo on tears, faster surgery if needed. EyeWiki

  2. Protective eyewear (sports glasses, polycarbonate lenses)
    Purpose: reduce trauma risk to already fragile eyes.
    How it helps: shatter-resistant lenses lower chance of blunt trauma triggering a tear/detachment (common-sense best practice in high myopia).

  3. Activity modification
    Purpose: avoid high-impact pressure changes or hits to the head/eyes.
    How it helps: limit collision sports, heavy Valsalva, trampoline/bungee; choose lower-risk activities to reduce retinal tear risk.

  4. Low-vision rehabilitation
    Purpose: maximize usable vision from day one.
    How it helps: lighting, magnifiers, electronic readers, large-print strategies, contrast tweaks, screen settings, phone accessibility.

  5. Educational accommodations
    Purpose: keep learning on track.
    How it helps: front-row seating, digital materials, extra time, audio books, tactile learning; Individualized Education Plan (IEP) when available.

  6. Orientation & mobility training
    Purpose: safe navigation as vision declines.
    How it helps: cane skills, route planning, environmental scanning, assistive tech.

  7. Occupational therapy
    Purpose: daily-living independence.
    How it helps: task simplification, home modifications, vision-friendly kitchen/bath setups.

  8. Physiotherapy (when motor issues exist)
    Purpose: support gross motor skills if balance or motor delays appear.
    How it helps: targeted balance/coordination work.

  9. Family genetic counseling
    Purpose: understand inheritance, carrier risk, and reproductive options.
    How it helps: explains autosomal-recessive risk (25% per pregnancy) and options like carrier testing, PGT-M. EyeWiki

  10. Neurosurgical evaluation (if skull defect/encephalocele)
    Purpose: decide on timing/need for repair.
    How it helps: prevents CSF leaks/infection; protects brain tissue. MedlinePlus

  11. Proactive detachment education
    Purpose: fast action saves vision.
    How it helps: teach “flashes, floaters, curtain over vision” → same-day emergency assessment.

  12. Home safety & lighting optimization
    Purpose: reduce falls/eye injuries.
    How it helps: high-contrast steps/edges, nightlights, task lamps, decluttered pathways.

  13. Spectacle/Contact lens optimization
    Purpose: best possible focus with extreme myopia.
    How it helps: high-index lenses, proper vertex distance; specialty contacts if tolerated.

  14. Dry-eye care
    Purpose: comfort and stable vision.
    How it helps: humidify, blink breaks, preservative-free lubricants (medicine-free support).

  15. Psychological support/peer groups
    Purpose: coping with chronic rare disease.
    How it helps: lowers anxiety, improves self-management.

  16. Vision-friendly tech
    Purpose: maximize independence.
    How it helps: screen readers, zoom, high-contrast modes, smart assistants.

  17. Sun/UV protection
    Purpose: comfort, glare control, possible long-term retinal light protection.
    How it helps: quality sunglasses/hat; photochromic options.

  18. Peri-operative planning
    Purpose: lower surgical risks.
    How it helps: anesthesia planning for high myopia; retina-savvy surgical team; informed consent about re-detach risk. EyeWiki

  19. Fall-back emergency plan
    Purpose: speed to care.
    How it helps: know which hospital can do pediatric/complex retinal surgery; transport plan.

  20. Lifestyle health basics
    Purpose: support healing and surgery readiness.
    How it helps: sleep, balanced diet, vaccinations up to date to reduce post-op infection risks.


Drug treatments

Important: dosing is individualized by your clinician; pediatric dosing differs. These medications treat complications seen in KNO (myopic CNV, glaucoma, inflammation, macular edema), not the gene defect itself.

  1. Anti-VEGF injections for myopic CNV (e.g., ranibizumab 0.5 mg or aflibercept 2 mg intravitreal, typically monthly “loading” then treat-and-extend/PRN)
    Purpose: stop abnormal leaky blood vessels under the macula (if they occur in high myopia).
    Mechanism: blocks VEGF to dry fluid and stabilize vision.
    Common side effects: transient eye irritation, rare infection/IOP spikes. (Standard myopic-CNV care; not KNO-specific.)

  2. Topical glaucoma drops (if glaucoma develops)
    Examples/dosing: latanoprost 0.005% 1 drop qHS, timolol 0.5% 1 drop BID, brimonidine 0.2% TID, dorzolamide 2% TID.
    Purpose: lower eye pressure to protect the nerve.
    Mechanisms: increase outflow (prostaglandins), reduce fluid production (beta-blockers/CAIs), or both.
    Side effects: redness, stinging; systemic effects (e.g., timolol) in susceptible patients. EyeWiki

  3. Oral/Topical Carbonic Anhydrase Inhibitors for macular edema
    Examples: acetazolamide 250–500 mg/day divided; topical dorzolamide 2%.
    Purpose: reduce cystoid macular edema when present.
    Mechanism: reduces fluid accumulation in retina.
    Side effects: tingling, fatigue, kidney stone risk (oral forms).

  4. Post-op anti-inflammatory eye drops (e.g., prednisolone acetate 1% with taper; NSAID drops if indicated)
    Purpose: settle inflammation after retinal or lens surgery.
    Mechanism: blocks inflammatory pathways.
    Side effects: steroid IOP rise, delayed wound healing.

  5. Post-op antibiotic drops (e.g., moxifloxacin 0.5% QID for ~1 week as directed)
    Purpose: lower infection risk after eye surgery.
    Mechanism: broad-spectrum antibacterial.
    Side effects: irritation, allergy (rare).

  6. Cycloplegic/mydriatic drops (e.g., atropine 1% short course post-op as directed)
    Purpose: pain relief, prevent synechiae after some surgeries.
    Mechanism: relaxes ciliary muscle, dilates pupil.
    Side effects: light sensitivity, near blur.

  7. Low-dose atropine for childhood myopia control (e.g., 0.01–0.05% qHS, off-label)
    Purpose: slow myopia progression in select children under an eye specialist’s care.
    Mechanism: not fully clear; likely retinal and scleral signaling effects.
    Note: benefit/risk should be weighed carefully in KNO; not proven to change detachment risk.

  8. Antibiotics/antivirals when clinically indicated
    Purpose: treat intercurrent ocular infection (not routine).
    Mechanism: pathogen-specific.
    Side effects: drug-specific.

  9. Lubricating eye drops/gel
    Purpose: relieve dryness/irritation to stabilize vision.
    Mechanism: tear film support.
    Side effects: minimal.

  10. Systemic medications for non-ocular issues when present (e.g., antiepileptics for seizures in the minority with CNS findings)
    Purpose: symptom control beyond the eye.
    Mechanism/side effects: drug-specific (managed by neurology). PMC


Dietary / molecular & other supportive supplements

No supplement has been proven to treat Knobloch syndrome. A few have general retina/nerve or ocular surface support data in other conditions. Typical adult doses shown; children/pregnancy need specialist advice.

  1. Lutein 10 mg + Zeaxanthin 2 mg daily – macular pigment support; antioxidant action.

  2. Omega-3 (EPA/DHA) 1,000 mg daily – anti-inflammatory; tear-film support.

  3. Vitamin D3 (per labs, often 1000–2000 IU/day) – immune and neuromuscular support.

  4. Vitamin B-complex (B1/B6/B12) – nerve metabolism; correct documented deficiencies.

  5. Zinc 15 mg + Copper 2 mg – antioxidant enzyme co-factors (avoid high doses without guidance).

  6. CoQ10 100–200 mg/day – mitochondrial support; studied in neurodegeneration.

  7. Alpha-lipoic acid 300–600 mg/day – antioxidant; glucose/nerve support.

  8. N-acetylcysteine 600 mg 1–2×/day – glutathione precursor; antioxidant.

  9. Resveratrol 100–250 mg/day – antioxidant/anti-angiogenic signals in labs.

  10. Curcumin (enhanced-bioavailability) as directed – anti-inflammatory signaling.

  11. Magnesium 200–400 mg/day – muscle/nerve function; sleep; avoid excess if renal issues.

  12. Taurine 500–1000 mg/day – retinal cell osmoprotection (preclinical/limited clinical).

  13. Astaxanthin 6–12 mg/day – antioxidant studied for eye fatigue.

  14. Saffron 20–30 mg/day – small trials in AMD for visual function.

  15. Probiotic yogurt/foods or capsules – general anti-inflammatory gut support.

Again: these do not “fix” the gene or stop detachment; they’re supportive only.


Regenerative / stem-cell–type” therapies

There are no approved regenerative or stem-cell drugs for KNO. Below are examples from broader retinal-degeneration research; availability and dosing are trial-specific and not routine:

  1. CNTF-secreting intraocular implant (NT-501 / revakinagene taroretcel-lwey)
    Function/mechanism: continuous release of ciliary neurotrophic factor to support photoreceptors.
    Status: phase 1/2 studies in other retinal diseases show safety and biological activity; not KNO-specific; access via trials only. New England Journal of Medicine EvidencePNASIOVS

  2. Retinal progenitor cell injections (e.g., jCell/famzeretcel)
    Function/mechanism: paracrine trophic support and potential integration.
    Status: phase 2b data in retinitis pigmentosa; ongoing trials; not KNO-specific. Ophthalmology TimesClinicalTrials.gov

  3. AAV-based ocular gene therapy (conceptual for COL18A1)
    Function/mechanism: deliver a working gene copy to retinal cells.
    Status: AAV is widely used for inherited retinal disease trials; no clinical KNO-specific trial yet. IOVSMDPI

  4. CRISPR/base-editing (preclinical)
    Function/mechanism: correct pathogenic variants in vitro/animal models.
    Status: platform progressing for IRDs generally; not KNO-specific; preclinical. PMC

  5. RPE/photoreceptor cell replacement from iPSCs
    Function/mechanism: replace lost cells or provide trophic support.
    Status: early-phase trials in selected IRDs/AMD; none specific to KNO yet. PMC

  6. Neuroprotective small molecules (various)
    Function/mechanism: target oxidative stress/excitotoxicity pathways.
    Status: exploratory; not approved for KNO.

Bottom line: outside a clinical trial, these are not used for Knobloch syndrome today.


Surgeries

  1. Occipital encephalocele/skull-defect repair (neurosurgery)
    What happens: close the bone/soft-tissue defect; protect brain and prevent CSF leak/infection.
    Why: safety and long-term protection. MedlinePlus

  2. Pars plana vitrectomy (PPV) for retinal detachment (often with silicone oil or gas and sometimes combined with scleral buckle)
    What happens: remove vitreous traction, seal breaks, support retina with gas/oil; buckle supports the wall of the eye.
    Why: re-attach the retina; combined PPV + buckle tends to yield better anatomic success in KNO than single approaches. ScienceDirectOphthalmology Advisor

  3. Scleral buckle (SB)
    What happens: a silicone band indents the eye wall to relieve traction at retinal breaks.
    Why: part of primary or combined detachment repair; sometimes used preventively in select cases (evidence limited). Ophthalmology Advisor

  4. Laser or cryo-retinopexy (treatment for tears; debated for “prophylaxis”)
    What happens: laser burns or freezing create adhesive scar around a tear or weak area.
    Why: secure a tear to reduce detachment risk; prophylaxis in KNO is controversial and not strongly evidence-based. EyeWikiOphthalmology Advisor

  5. Lens surgery (lensectomy/cataract extraction)
    What happens: remove dislocated/opaque lens when it harms vision or blocks care.
    Why: improve vision or allow retina access; note higher capsular fragility risk in KNO. EyeWiki


Ways to reduce risk / prevent complications

  1. Early, regular care with a retina specialist (childhood onward). EyeWiki

  2. Know detachment warning signs and seek same-day care.

  3. Protect the eyes (sports goggles; avoid high-impact contact sports).

  4. Seatbelts/helmet use to reduce head/eye trauma.

  5. Avoid forceful eye rubbing.

  6. Manage refractive error (proper glasses/contacts).

  7. Optimize home/school lighting and contrast.

  8. Keep vaccinations current (helps reduce infection risk around surgeries).

  9. Healthy sleep, nutrition, hydration to support recovery.

  10. Family genetic counseling for future pregnancies. EyeWiki


When to see a doctor urgently vs routinely

  • Urgently (same day): sudden flashes/floaters, a dark curtain across vision, sudden vision drop, painful red eye, head trauma, new swelling/soft spot at the back of the head.

  • Soon (days–weeks): increasing blur, double vision, new eye strain, headaches, trouble in school tasks due to vision.

  • Routinely: scheduled retina checks (often every 3–6 months in childhood, individualized), neurosurgery follow-up if skull repair, and genetics appointments for family planning. EyeWiki


What to eat and what to avoid

  1. Do: plenty of colorful vegetables (spinach, kale, peppers) for lutein/zeaxanthin. Avoid: ultra-processed snacks replacing real meals.

  2. Do: oily fish 1–2×/week (sardine, salmon) for omega-3s. Avoid: frequent deep-fried fast food.

  3. Do: nuts/legumes (almonds, lentils) for minerals. Avoid: high-salt packaged foods (can worsen post-op swelling).

  4. Do: whole grains for steady energy. Avoid: sugar spikes from sweets/soft drinks.

  5. Do: hydrate well (water). Avoid: energy drinks excess (dry-eye, sleep issues).

  6. Do: dairy/fortified alternatives for vitamin D/calcium as advised. Avoid: megadose supplements without labs.

  7. Do: citrus/berries (vitamin C). Avoid: alcohol excess (healing, balance).

  8. Do: olive-oil-based cooking. Avoid: repeated-use frying oils.

  9. Do: probiotic yogurt/fermented foods for gut health. Avoid: fad “detox” products.

  10. Do: consistent, balanced meals around surgery. Avoid: new restrictive diets when healing.


Frequently Asked Questions

1) Can Knobloch syndrome be cured?
Not today. Care aims to protect vision and repair complications. Research in gene/cell therapy is ongoing but not KNO-specific yet. IOVS

2) Will every child with KNO lose vision?
Severity varies. Many develop serious retinal problems over time; early monitoring and timely surgery help preserve vision where possible. EyeWiki

3) Is an occipital defect always present?
No. Some patients have clear eye findings without a skull defect. EyeWiki

4) What causes it?
Usually COL18A1 gene variants affecting collagen XVIII; rare Knobloch-like cases involve ADAMTS18. EyeWiki

5) How is it inherited?
Autosomal recessive—both parents are typically healthy carriers; each pregnancy has a 25% chance to be affected. EyeWiki

6) What’s the biggest eye risk?
Retinal detachment, often in later childhood/teens; it can recur. EyeWiki

7) Is preventive laser or buckle recommended?
Some centers consider it case-by-case; evidence is limited and detachments can still occur. Ophthalmology Advisor

8) Which detachment surgery works best?
Data in KNO suggest combined PPV + scleral buckle often gives better anatomic success than one technique alone. Outcomes vary by eye. ScienceDirect

9) Are there non-eye problems?
A minority have brain findings (e.g., polymicrogyria) or other systemic anomalies. Screening is individualized. PMC

10) Can glasses fix the problem?
Glasses/contacts help high myopia focus, but they do not stop retinal degeneration/detachment risk. EyeWiki

11) Can low-dose atropine slow myopia here?
Sometimes used off-label in children; benefit in KNO is uncertain—specialist judgment required.

12) Do supplements help?
They may support general eye health, but none are proven to treat KNO or prevent detachment.

13) Can children play sports?
Encourage low-impact, non-contact activities with protective eyewear; avoid collision sports.

14) Should the whole family get genetic testing?
Carrier testing for parents/siblings is often helpful for planning. EyeWiki

15) Where can I read more?
Good overviews exist for patients and clinicians (MedlinePlus Genetics, GARD, EyeWiki). MedlinePlusGenetic Rare Diseases CenterEyeWiki

Disclaimer: Each person’s journey is unique, treatment planlife stylefood habithormonal conditionimmune systemchronic disease condition, geological location, weather and previous medical  history is also unique. So always seek the best advice from a qualified medical professional or health care provider before trying any treatments to ensure to find out the best plan for you. This guide is for general information and educational purposes only. Regular check-ups and awareness can help to manage and prevent complications associated with these diseases conditions. If you or someone are suffering from this disease condition bookmark this website or share with someone who might find it useful! Boost your knowledge and stay ahead in your health journey. We always try to ensure that the content is regularly updated to reflect the latest medical research and treatment options. Thank you for giving your valuable time to read the article.

The article is written by Team RxHarun and reviewed by the Rx Editorial Board Members

Last Updated: August 10, 2025.

PDF Document For This Disease Conditions References

To Get Daily Health Newsletter

We don’t spam! Read our privacy policy for more info.

Download Mobile Apps
Follow us on Social Media
© 2012 - 2025; All rights reserved by authors. Powered by Mediarx International LTD, a subsidiary company of Rx Foundation.
RxHarun
Logo