Temporary Keratoprosthesis

A temporary keratoprosthesis is a special, short-term, artificial cornea that a surgeon uses during complex eye surgery when the real cornea is too cloudy to see through. The device looks like a clear window that sits in the opening of the cornea for a short time during the operation. The surgeon removes the cloudy cornea, places the temporary clear window, and then can safely look inside the eye to treat urgent problems in the retina, vitreous, lens, or other inner structures. After finishing the inside work, the surgeon removes the temporary window and usually places a donor corneal graft to close the eye. The goal is very simple and very important: to give the surgeon a clear view, to protect the delicate parts of the eye while they are being repaired, and to support a safer and more effective surgery when the natural cornea is not usable for visualization.

A temporary keratoprosthesis is a clear, artificial “window” that surgeons briefly sew onto the eye during complex surgery. It replaces a cloudy or damaged cornea only for the duration of the operation so the surgeon can clearly see inside the eye and safely repair the retina or other structures. When the inner eye work is finished, the temporary window is removed and a permanent corneal graft (or other planned surface repair) is placed. In short: TKP = see-through, short-term cornea used to make the inside work possible, not a permanent implant. This definition matches how regulators and clinical texts describe it: a device used intraoperatively to aid visualization and removed after surgery. U.S. Food and Drug AdministrationEyeWiki

A temporary keratoprosthesis is different from a permanent keratoprosthesis. A permanent keratoprosthesis is designed to remain in the eye long term for people who cannot keep a clear corneal graft. A temporary keratoprosthesis is only used during the operation, often for minutes to a few hours, and is removed before the operation ends. It is a tool for the surgeon and a bridge for the patient, because it connects the outside world to the inside of the eye with a clear and stable optical window during a critical and time-sensitive procedure.

A temporary keratoprosthesis is helpful when the cornea is so scarred, swollen, ulcerated, or blood-stained that the surgeon cannot see the retina or other inner parts at all. It is also helpful during “open-sky” phases of surgery, when the eye is open and needs a stable, clear, pressurizing cover to prevent collapse, bleeding, or sudden pressure changes. The device is usually made from clear plastic like PMMA or medical-grade silicone, with a shape that matches the corneal opening and a central optical zone that gives a wide field of view. It can be sutured to the corneal rim, it can include grooves or flanges that help it sit securely, and some designs allow fluid infusion to maintain safe pressure inside the eye while the surgeon works.

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Types of Temporary Keratoprosthesis

By material and optical design:
Some temporary keratoprostheses are rigid and made of PMMA, which gives very clear optics and a stable window. Some are softer and made of silicone or similar elastomers, which can be gentler on tissue and easier to place in tight or irregular openings. The central optical zone may be wider for wide-field visualization, and the edges are shaped to match the cut corneal rim so that the window sits flush and stable during surgery.

By fixation method (how it stays in place):
A common design is sutured, where tiny corneal sutures pass through small holes or notches in the device and into the remaining corneal rim, which keeps the window from shifting when instruments go in and out. There are also snug-fit designs that rely on a stepped edge or a compressive fit against the corneal rim to stay steady. Some designs include small tabs that make handling and suturing safer and faster during the open-sky period.

By fluid and pressure support:
Some temporary keratoprostheses are simple clear windows with no fluid ports. Others are made to work with infusion lines so that balanced salt solution can flow in and keep the eye’s pressure at a safe level while instruments move inside the eye. This helps prevent the eye from collapsing and helps reduce the risk of bleeding or choroidal effusion.

By optical field (standard vs wide-field):
Standard optical windows allow a clear, axial view through the pupil and into the posterior segment. Wide-field designs have a larger, flatter central zone that gives the surgeon a broader view of the retina, which is very useful for complex retinal detachment repair, for removing membranes, or for finding and removing an intraocular foreign body.

By patient and case needs (adult vs pediatric; routine vs salvage):
Pediatric eyes are smaller, more elastic, and more reactive, so surgeons may prefer smaller diameter windows and gentler fixation. In salvage trauma cases, the surgeon may choose a model with rapid placement and robust pressure control, because speed and stability can reduce the risk of expulsive bleeding or retinal ischemia during the most dangerous moments of open-sky surgery.

A temporary keratoprosthesis is a clear, removable window used only during eye surgery when the natural cornea is not clear enough to see through. It lets the surgeon see the inside of the eye clearly, it keeps the eye formed and pressurized during the most delicate steps, and it protects the sensitive tissues while instruments pass in and out. It shortens operating time by giving a wide view right away, it lowers the chance of dangerous pressure drops, and it allows complex posterior segment procedures to be done at the same sitting as the corneal transplant. In simple terms, it is a safe, clear, temporary door that the surgeon opens to fix what is broken inside the eye and then closes with a new corneal graft when the inside repairs are done.

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Causes (reasons) for needing a Temporary Keratoprosthesis

1) Dense corneal scar from old infection or trauma:
A deep white scar can block all view to the back of the eye, so the surgeon cannot see the retina to repair it. A temporary keratoprosthesis replaces the scarred cornea during surgery and gives a clear view for retinal work.

2) Active infectious keratitis with large ulcer and infiltrate:
An infected ulcer makes the cornea cloudy and fragile, which hides the posterior segment and increases the risk of perforation. The temporary window allows safe access for vitrectomy if there is endophthalmitis or retinal detachment, and then the surgeon can place a therapeutic corneal graft.

3) Severe corneal edema or bullous keratopathy:
Swollen corneal layers scatter light and cause a milky haze. When medical therapy fails and urgent posterior surgery is needed, the temporary window restores clarity during the operation.

4) Chemical burn with diffuse stromal opacification:
Alkali or acid burns can opacify and vascularize the cornea quickly. A temporary window allows inner-eye repair and can be followed by a tectonic or optical graft once the inside is stabilized.

5) Thermal burn or blast injury:
Heat and blast can denature the cornea and make it opaque and irregular. A temporary window gives a stable, smooth optical surface for the surgery inside the eye.

6) Corneal blood staining after prolonged hyphema:
Blood can diffuse into corneal layers and cause a chocolate-brown haze that blocks the view. The temporary window removes the visual barrier during combined anterior-posterior surgery.

7) Descemetocele or corneal melt with impending perforation:
A deep, thinned spot threatens to rupture, and the surgeon may need to open the eye under controlled conditions. The temporary window lets the surgeon keep the globe formed while addressing urgent posterior pathology.

8) Actual corneal perforation needing urgent open-sky repair:
When the cornea is open, the eye can collapse and bleed. The temporary window seals the opening, restores pressure, and lets the surgeon complete vitrectomy or retinal repair before a graft is placed.

9) Failed corneal graft with dense opacity:
A cloudy failed graft can hide retinal detachments, vitreous hemorrhage, or endophthalmitis. The window allows combined regrafting and posterior segment surgery in one sitting.

10) Advanced corneal vascularization and scarring from chronic inflammation:
Long-standing uveitis or ocular surface disease can cause heavy scarring that blocks the view, and the temporary window is the safe way to proceed with inside repairs.

11) Corneal dystrophy or degeneration with central haze (for example, advanced lattice or macular dystrophy):
When haze is severe and urgent vitreoretinal surgery is needed, the window gives a practical and safe optical path.

12) Band keratopathy covering the visual axis:
Calcium plaques make the cornea rough and opaque. If urgent posterior surgery cannot wait for surface treatments, the temporary window is chosen.

13) Stevens-Johnson syndrome or ocular cicatricial pemphigoid with dense scarring:
Severe surface disease may leave the cornea opaque and fragile, and the temporary window enables the surgeon to perform necessary inner repairs in a controlled, short exposure.

14) Endophthalmitis with opaque cornea:
Severe infection fills the cornea with inflammatory cells and edema. The temporary window allows immediate vitrectomy, removal of infectious debris, and injection of antibiotics inside the eye.

15) Intraocular foreign body with a corneal wound that has opacified:
Metal or glass inside the eye is an emergency, and scarring at the corneal wound can block the view, so the temporary window is the fastest way to see and remove the object safely.

16) Complex retinal detachment when the cornea is cloudy:
Proliferative vitreoretinopathy and giant retinal tears require wide visualization; the temporary window gives a wide, stable view when the cornea will not allow a standard, closed-globe approach.

17) Major globe trauma with combined corneal and posterior injuries:
When the front is damaged and the back is also torn or detached, a one-stage repair with a temporary window can reduce total surgical time and anesthesia exposure.

18) Congenital corneal opacity (such as Peters anomaly) with posterior segment disease:
In selected pediatric cases, a temporary window allows safe examination and repair of the retina before a graft is placed.

19) Persistent epithelial defect with deep stromal haze after multiple surgeries:
If scarring hides the posterior segment and there is an urgent need for inner repair, the window is used for clear and gentle access.

20) Infected or inflamed corneal graft with dense infiltrate:
A hot graft can become opaque quickly and hide dangerous posterior issues; the temporary window allows combined control of infection and posterior surgery.

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Symptoms and signs

1) Severe blurred vision:
The person cannot see shapes or details because the cornea is too cloudy for light to pass cleanly to the retina.

2) Eye pain or deep ache:
Inflammation, ulceration, or pressure changes can cause a constant or throbbing pain that may worsen with light or eye movement.

3) Redness:
The white part of the eye looks red due to dilated superficial and deep vessels, showing that the eye is irritated or inflamed.

4) Sensitivity to light (photophobia):
Bright light causes discomfort because the corneal surface is rough and inflamed and the iris reacts strongly.

5) Tearing or watery eye:
Reflex tearing increases when the corneal surface is not healthy, and tears may run down the cheek.

6) Foreign body sensation or gritty feeling:
The surface irregularity makes it feel like sand in the eye and blinking does not relieve the feeling.

7) Discharge:
There may be mucous, pus, or thick tears that signal infection or severe surface inflammation.

8) Halos and glare:
Lights look smeared with rings and starbursts because the cornea scatters the light in many directions.

9) Fluctuating vision across the day:
Vision may be a little clearer in the morning and worse later as swelling and surface dryness change.

10) Visible white or gray spot on the cornea:
Family members or the patient may notice a patch or plaque where the cornea has scarred or calcified.

11) Eyelid swelling and tenderness:
The lids can puff up with inflammation and may be painful to touch when infection or trauma is present.

12) Headache around the eye or brow:
Strain, inflammation, and pressure changes can cause a dull headache that surrounds the eye.

13) Poor night vision:
Scattered light and reduced contrast make low-light conditions especially hard.

14) Reduced contrast sensitivity even when reading big letters:
Black-on-white details fade and look washed out because the cloudy cornea loses fine image quality.

15) Trouble keeping the eye open (blepharospasm):
Reflex blinking becomes strong and frequent when the cornea is irritated, which can make examination difficult.

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Diagnostic tests

Physical examination tests (bedside and slit-lamp evaluation)

1) Visual acuity with and without pinhole:
This simple test measures how well the person sees letters or symbols at a set distance. The pinhole can improve focus if the main problem is irregular surface or refractive error, and it helps the clinician judge how much of the blur is due to the cornea versus deeper disease.

2) External inspection of lids, lashes, and ocular surface:
The clinician looks for swelling, redness, discharge, lid malposition, and exposure areas, because these clues show whether the corneal problem is isolated or part of a broader surface disorder that may affect surgical planning.

3) Pupillary reactions and relative afferent pupillary defect (RAPD) check:
A light is swung between the eyes to see if one optic nerve or retina is much weaker, which is important because a very weak retina or nerve lowers the expected vision after surgery and guides informed consent.

4) Slit-lamp biomicroscopy of the anterior segment:
A microscope with a bright, thin beam examines every corneal layer, the anterior chamber, the iris, and the lens. The clinician notes ulcer depth, infiltrate density, neovascularization, thinning, and any leak or perforation. These details tell the surgeon how urgent the situation is and how to prepare instrumentation and graft size.

5) Intraocular pressure assessment (tonometry or digital palpation if unsafe):
Pressure can be high due to inflammation or low due to leakage. Knowing the pressure helps protect the optic nerve, prevent expulsive bleeding, and plan safe anesthesia and fluid targets during surgery.

Manual tests (simple chair-side procedures)

6) Fluorescein staining pattern of the cornea:
A safe dye highlights damaged epithelium and shows where the surface is missing, rough, or ulcerated. Pooling and staining patterns help judge healing potential and risk of perforation.

7) Seidel test for aqueous leak:
After fluorescein is placed, the clinician looks for clear streams that wash away the dye from a wound site, which proves there is a leak and confirms the need for urgent tectonic repair and possibly a temporary keratoprosthesis.

8) Corneal sensation testing (cotton wisp or Cochet-Bonnet esthesiometer):
Reduced sensation is common in herpetic disease, diabetes, or neurotrophic cornea, and it predicts slower healing and higher risk of surface breakdown after surgery, which affects graft choice and postoperative care.

9) Schirmer test for tear production:
A small strip of paper measures how many tears are made over a few minutes. Very low values warn of severe dryness that must be treated aggressively to protect the new graft after the temporary window is removed.

10) Tear film break-up time (TBUT):
After a blink, the clinician times how quickly the tear film becomes patchy. A short time means an unstable tear film that increases symptoms and complicates surface healing, so lubrication plans must be stronger.

Laboratory and pathological tests

11) Corneal scraping for Gram stain and culture (bacterial):
A sterile spatula gently collects cells from the ulcer edge to identify bacteria under a microscope and to grow them in the lab. Results guide antibiotic choice and timing of surgery.

12) KOH wet mount and fungal culture:
A drop of potassium hydroxide is mixed with the sample to look for branching fungal filaments, which are often missed clinically but require different drugs and careful graft handling.

13) Acanthamoeba testing or culture where exposure risk exists:
Contact lens wear in water increases risk for this organism, and special culture media or stains can show cysts, which change the surgical and medical plan.

14) PCR testing for herpes simplex or varicella zoster virus:
When herpetic disease is suspected, PCR can confirm the virus quickly so antiviral therapy can be optimized before and after surgery to reduce recurrence on the new graft.

15) Histopathology and microbiology of the removed corneal button or membrane:
After the temporary window step, the excised corneal tissue is sent to pathology. The report confirms the cause of opacity, measures inflammation and organisms, and informs future prevention.

Electrodiagnostic tests

16) Full-field electroretinography (ERG):
If the cornea blocks the view and B-scan shows a retina but vision is very poor, ERG measures how well the retina responds to light. A flat ERG suggests poor retinal function, which affects prognosis and helps with honest counseling.

17) Visual evoked potentials (VEP):
VEP checks the electrical response from the visual cortex to a light stimulus and helps separate corneal opacity from optic nerve or brain pathway issues when the clinical picture is unclear.

Imaging tests

18) B-scan ocular ultrasonography:
This ultrasound looks through opaque media to find retinal detachment, vitreous hemorrhage, choroidal detachment, tumors, or foreign bodies. It is essential when the cornea is opaque, and it helps plan whether posterior segment surgery is needed with the temporary window.

19) Anterior segment optical coherence tomography (AS-OCT):
AS-OCT gives cross-sectional images of the cornea, showing ulcer depth, Descemet’s membrane position, and any microperforation, which guides the size of trephination and the urgency of tectonic support.

20) Corneal tomography or topography (Scheimpflug or Placido systems) when possible:
If there is enough clarity at the periphery, tomography maps corneal thickness and curvature. Even partial maps help size the graft, choose trephine diameters, and anticipate irregular astigmatism after surgery.

Non-pharmacological treatments

(Each item explains: description → purpose → simple mechanism)

1. Protective eye shield and positioning. After surgery, a rigid shield and proper head positioning protect the graft and help tamponade (gas/oil) work by gravity → lowers risk of trauma and graft dislodgement; keeps intraocular tamponade where the surgeon wants it. (Standard surgical care)

2. Strict eye hygiene (no rubbing, clean lids). Gentle lid hygiene and hand washing → reduces surface bacteria and mechanical stress on fresh sutures → lowers infection and suture-related irritation. (Standard postoperative advice)

3. Suture care and timely removal/adjustment. Planned suture checks and selective removal → reduces irregular astigmatism and foreign-body sensation → smoother optical surface, better vision, fewer infiltrates. (Cornea practice norm)

4. Bandage contact lens (BCL) when indicated. A soft lens shields healing epithelium and sutures → reduces pain and promotes epithelial closure by lowering friction and tear evaporation. (Cornea practice norm)

5. Lubrication regimen (preservative-free tears/gel/ointment). Thick tears and gels supplement the tear film → reduce shear on epithelium and dilute inflammatory mediators → faster surface healing, better comfort. (Cornea practice norm)

6. Punctal occlusion (temporary plugs) for dry surface. Keeps tears on the eye longer → maintains a hydrated surface so epithelium can migrate and seal defects. (Cornea practice norm)

7. Moisture chamber or humidifier. A moisture shield or room humidifier → decreases evaporation → protects graft epithelium and stabilizes the tear film at night. (Supportive care)

8. UV-blocking eyewear outdoors. Sunglasses reduce photophobia and UV-induced inflammation → protects healing tissue and graft endothelium from oxidative stress. (Supportive care)

9. Nutritional optimization (protein + micronutrients). Adequate protein and vitamins (C, A, zinc) support collagen synthesis and immune function → tissue repairs stronger and faster. (Wound-healing basics)

10. Smoking cessation. Removing tobacco toxins improves microvascular perfusion and lowers infection risk → better graft survival and epithelial healing. (Surgical outcome factor)

11. Glycemic control in diabetes. Tighter glucose control → improves neutrophil function and collagen cross-linking → fewer infections and stronger wound healing. (Surgical outcome factor)

12. Lid margin disease control (warm compresses, hygiene). Treats blepharitis/meibomian dysfunction → lowers bacterial load and toxic tear lipids → calmer surface and fewer infiltrates. (Cornea practice norm)

13. Treat ocular surface inflammation (non-drug measures as adjuncts). Cold compresses, environmental control → reduce neurogenic/evaporative triggers → less reflex inflammation. (Adjunctive care)

14. Amniotic membrane (in indicated cases). Surgeon may place a cryopreserved amniotic membrane to promote epithelialization and down-regulate inflammation via growth factors and anti-fibrotic signaling. PubMedCureus

15. Autologous serum tears (ASEDs) or platelet-rich plasma (PRP) drops (specialist-prepared). Blood-derived tears provide epithelial growth factors that can help persistent epithelial defects; evidence is mixed for ASEDs and increasingly supportive for PRP. PubMed+1bmjophth.bmj.comPMC

16. Rigid gas permeable/scleral lens fitting (later phase). Once the graft is stable, specialty lenses can neutralize irregular astigmatism → better optics without stressing sutures. (Corneal rehab)

17. Home safety changes (fall-proofing). After TKP/PKP, vision may be fluctuating; improving lighting and removing trip hazards → lowers blunt trauma risk to the operated eye. (General safety)

18. Adherence coaching and written schedules. Clear, printed drop schedules and reminders → prevent missed antibiotic/anti-inflammatory doses → fewer complications. (Patient-safety measure)

19. Regular IOP monitoring visits. TKP cases often involve combined retina surgery; pressure checks catch steroid or angle issues early → preserve optic nerve. (Postop standard)

20. Vaccination review for open-globe injuries (e.g., tetanus). Ensuring tetanus prophylaxis in trauma → prevents rare but serious infection; coordinated by the surgical team in the acute phase. (Trauma standard)

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Drug treatments commonly used around TKP/combined PKP-PPV

(Each item: class → typical adult dosing/time → purpose → mechanism → key side effects. Always follow your surgeon’s exact plan.)*

1. Topical fluoroquinolone (e.g., moxifloxacin 0.5% q.i.d., peri-op).
   Purpose: prevent surface infection while sutures and epithelium heal. Mechanism: DNA gyrase/topoisomerase inhibition in bacteria. Side effects: stinging, rare allergy; overuse may foster resistance. (Standard corneal prophylaxis)

2. Topical fourth-gen fluoroquinolone “load” (peri-op q2–4h first 24–48 h then taper).
   Purpose: higher early surface coverage when exposure risk is greatest. Mechanism: as above. Side effects: surface dryness, taste disturbance via nasolacrimal drainage. (Surgeon-directed)

3. Topical corticosteroid (prednisolone acetate 1% q1–2h, then taper).
   Purpose: control graft and surface inflammation. Mechanism: blocks phospholipase A2 → lowers prostaglandins/cytokines. Side effects: IOP rise, delayed epithelial healing, infection flare (e.g., HSV). (Corneal graft standard)

4. Cycloplegic/mydriatic (atropine 1% b.i.d. or cyclopentolate).
   Purpose: pain relief (ciliary spasm) and posterior synechiae prevention. Mechanism: muscarinic blockade in the ciliary body/iris. Side effects: light sensitivity, blurred near vision; systemic anticholinergic effects if overused. (Uveitis/surgery standard)

5. IOP-lowering drops (e.g., timolol 0.5% b.i.d., brimonidine t.i.d., dorzolamide t.i.d.).
   Purpose: prevent or treat postoperative eye-pressure spikes. Mechanisms: β-blocker reduces aqueous production; α-agonist reduces production/increases uveoscleral outflow; carbonic anhydrase inhibitor reduces production. Side effects: fatigue/bradycardia (β-blocker), dry mouth (α-agonist), stinging/paresthesias (CAI). (Post-PPV/PKP pressure control)

6. Oral acetazolamide (250 mg q6–8 h short term if needed).
   Purpose: additional IOP control. Mechanism: systemic carbonic anhydrase inhibition. Side effects: tingling, diuresis, kidney stone risk, sulfa cross-reactivity. (Short-course pressure control)

7. Topical antibiotic-steroid combinations (select cases).
   Purpose: simplify regimen where epithelial integrity is poor. Mechanism: combined antimicrobial + anti-inflammatory action. Side effects: steroid-related IOP rise; choose agent guided by surgeon to avoid resistance. (Convenience/coverage)

8. Systemic antibiotics for open-globe trauma (agent/dose per protocol).
   Purpose: prevent endophthalmitis in ruptured globe. Mechanism: systemic coverage crosses ocular tissues. Side effects: drug-specific; coordinated with trauma team. (Trauma standard of care)

9. Antiviral prophylaxis (e.g., acyclovir 400 mg b.i.d.) in herpetic risk.
   Purpose: reduce HSV recurrence that can threaten a fresh graft. Mechanism: viral DNA polymerase inhibition. Side effects: GI upset, renal dose adjustment. (Herpetic eye disease protocols)

10. Intravitreal/periocular anti-infectives (e.g., vancomycin/ceftazidime) or steroid administered intra-op when indicated.
    Purpose: treat or prevent posterior segment infection/inflammation in combined cases (surgeon-only use). Mechanism: local high concentration; steroid dampens inflammation. Side effects: drug-specific (retina-surgeon managed). EyeWiki

*Doses/timing above are illustrative of common adult patterns; exact choices and schedules vary by indication, lens status, tamponade choice, and surgeon preference.

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Dietary molecular supplements

These do not replace prescriptions. They support normal healing and surface comfort.

1. Vitamin C (ascorbic acid 500–1000 mg/day).
   Function: collagen cross-linking and antioxidant support → stronger wound healing. Mechanism: cofactor for proline/lysine hydroxylases in collagen.

2. Protein/essential amino acids (target ~1.2 g/kg/day).
   Function: tissue repair and immune proteins. Mechanism: substrate for collagen and cellular turnover.

3. Omega-3 EPA+DHA (≈1 g/day combined).
   Function: anti-inflammatory tear lipid profile. Mechanism: shifts eicosanoid balance from AA-derived mediators.

4. Zinc (8–11 mg/day).
   Function: epithelial turnover and immune function. Mechanism: cofactor for DNA/RNA polymerases and antioxidant enzymes.

5. Vitamin A (dietary; avoid high-dose pills unless deficient).
   Function: epithelial differentiation. Mechanism: retinoid-driven gene expression in mucosal epithelium.

6. Lutein + Zeaxanthin (10 mg + 2 mg/day).
   Function: macular antioxidant support, glare reduction. Mechanism: blue-light filtering carotenoids.

7. Vitamin D3 (800–1000 IU/day or per labs).
   Function: immune modulation and muscle function (safer mobility). Mechanism: nuclear receptor–mediated transcription.

8. **Arginine (3–6 g/day) and 9) Glutamine (5–10 g/day) if diet is poor.
   Function: collagen and immune cell fuel. Mechanism: nitric-oxide precursor (arginine) and enterocyte/lymphocyte substrate (glutamine).

9. Curcumin (500–1000 mg/day with food; check interactions).
   Function: anti-inflammatory adjunct. Mechanism: NF-κB signaling modulation.

Pre-op caveat: your surgeon may ask you to pause high-dose fish oil, vitamin E, garlic, ginkgo, or ginseng before surgery because of bleeding concerns—follow the surgical instructions you’re given.

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Immunity/regenerative/stem-cell–type” medicines — what’s truly used

There are no approved “stem cell drugs” to improve outcomes of TKP itself. In practice, cornea teams use immunomodulators for high-risk grafts and regenerative biologics for the ocular surface:

1. Systemic cyclosporine (under specialist care).
   Use: high-risk corneal transplantation to reduce rejection. Mechanism: calcineurin inhibition suppresses T-cell activation. Notes: improves 1-year rejection-free survival in high-risk cases; monitor kidney/BP. PMC

2. Mycophenolate mofetil (MMF).
   Use: another option for high-risk grafts. Mechanism: inhibits inosine monophosphate dehydrogenase in lymphocytes. Notes: helps rejection-free survival; monitor GI, leukopenia. PMC

3. Tacrolimus (systemic or topical compounding).
   Use: sometimes favored when risk is very high or CsA insufficient. Mechanism: calcineurin inhibition similar to CsA. Notes: evidence supports benefit, but systemic side effects require close monitoring. BioMed Central

4. Topical cyclosporine (0.05–0.1%).
   Use: chronic surface inflammation and tear film instability around a graft. Mechanism: local T-cell suppression to calm ocular surface. (Immunomodulator; widely used in cornea clinics)

5. Autologous blood-derived tears (ASEDs/PRP).
   Use: persistent epithelial defects or severe dryness threatening the graft. Mechanism: growth factors (EGF, TGF-β, fibronectin) promote epithelial migration. Evidence: RCTs and reviews show PRP and ASEDs can help, with PRP often at least non-inferior and sometimes superior for staining outcomes. PMCbmjophth.bmj.comPubMed

6. Cenegermin 0.002% (rhNGF).
   Use: neurotrophic keratitis that impairs healing, which can complicate grafts. Mechanism: nerve growth factor supports corneal nerve and epithelium recovery; FDA-approved in 2018. NCBIFDA Access Data

Experimental cell-based therapies (e.g., cultivated limbal epithelial stem cells) exist in specialized centers and trials; availability and regulation vary by country. Your cornea specialist will advise if appropriate.

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Surgeries commonly performed with a TKP

1. Combined penetrating keratoplasty (PK) + pars plana vitrectomy (PPV).
   Procedure: remove opaque cornea → sew in TKP → perform PPV (clear vitreous, peel membranes, endolaser, tamponade) → remove TKP → place donor corneal graft.
   Why: to treat both the cornea and the retina in one session when the front window is opaque. EyeWikiLippincott Journals

2. Retinal detachment repair with endolaser and tamponade (gas/silicone oil).
   Procedure: reattach retina via PPV, laser around breaks, then fill with gas or silicone oil.
   Why: TKP provides the view needed when the cornea is not clear (e.g., post-trauma). WebEye

3. Scleral buckle added to PPV in trauma.
   Procedure: encircle band supports the peripheral retina, combined with PPV under TKP.
   Why: improves anatomic support in complex detachments; a classic combined approach. ScienceDirect

4. Secondary IOL fixation (e.g., Yamane technique) at time of PKP/PPV.
   Procedure: scleral fixation of a posterior-chamber lens during TKP-assisted combined surgery.
   Why: restores lens after trauma/cataract extraction while the eye is already open. PubMed

5. Glaucoma drainage device placement (selected cases).
   Procedure: tube shunt placed, often via a vitrectomy port during the combined case.
   Why: proactive control of postoperative pressure in high-risk eyes. EyeWiki

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Prevention steps (reduce risks before and after TKP/PKP)

1. Wear impact-rated eye protection at work/sport to prevent the trauma that often leads to TKP.

2. Treat corneal infections early; do not self-medicate with steroid drops.

3. Control blepharitis and dry eye to reduce bacterial load before surgery.

4. Stop smoking — better oxygen delivery, fewer infections.

5. Manage diabetes; good glucose control = stronger healing.

6. Follow pre-op medication holds (anticoagulants/herbals) exactly as instructed.

7. Do not rub the eye; use a shield at night until cleared.

8. Keep all early follow-ups (IOP, sutures, graft clarity checks are time-sensitive).

9. Use drops exactly as scheduled; bring your printed regimen to visits.

10. Ask about vaccines (e.g., tetanus after open-globe trauma) in emergency settings.

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When to see a doctor urgently after TKP/PKP

• Sudden pain, redness, swelling, or sticky discharge (possible infection).

• Drop in vision, new floaters, flashes, or a dark curtain (retina problem).

• Severe light sensitivity, nausea/headache with eye pain (pressure spike).

• Bandage lens falls out with gritty pain that does not settle.

• Any trauma or bump to the operated eye, even if it feels minor.

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What to eat — and what to avoid

Eat more of:

1. Lean protein (fish, eggs, legumes) daily to supply building blocks for healing.

2. Citrus/berries/kiwi for vitamin C (collagen).

3. Leafy greens (spinach, kale) for lutein/zeaxanthin.

4. Nuts/beans/whole grains for zinc and vitamin E (in food amounts).

5. Fatty fish (salmon, sardine) 2×/week for omega-3s.

Limit/avoid (around surgery and early healing):

1. High-dose fish oil, vitamin E, ginkgo/garlic/ginseng unless cleared (bleeding risk pre-op).
2. Alcohol excess, which dehydrates and impairs immunity.
3. Ultra-processed salty foods if you’re on steroids (fluid retention).
4. Smoking/vaping — harms wound healing.
5. Unverified supplements marketed as “eye stem-cell boosters” — no proven benefit and possible risk.

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FAQs

1. Is a TKP permanent? No. It’s only used during surgery and is removed before the operation ends. U.S. Food and Drug Administration

2. Why not just do retina surgery through the cloudy cornea? Because the surgeon cannot see safely; the TKP makes a clear, stable view. PubMed

3. What happens after the inside work is done? The TKP is removed and a donor corneal graft (or other planned repair) is sutured in place. EyeWiki

4. Is a TKP the same as the Boston KPro? No. Boston KPro is permanent for severe corneal blindness; TKP is temporary to help surgery. PMC

5. Which TKP type is best? Surgeons choose based on the case: Landers for wide field and pressure stability; Cobo for built-in infusion capability; Eckardt/quick-set options depending on availability. PMC+1ocularinc.com

6. What are success factors? Clear graft, attached retina, and controlled eye pressure; these are common outcome measures in TKP series. ResearchGate

7. What are the main risks? Graft failure, retinal redetachment, glaucoma/IOP spikes, and rarely phthisis; risk depends on the underlying injury. Ajo

8. Will I need more surgery later? Possibly. Complex trauma or infection sometimes needs staged procedures or suture adjustments. (Clinical reality reflected in TKP literature) Lippincott Journals

9. How long is recovery? Vision improves in steps as the surface heals and sutures settle; exact timing varies by case and retina status. (Post-PKP/PPV norm)

10. Can I rub my eye or sleep on that side? Avoid rubbing and use a shield at night until your surgeon clears you. (Standard advice)

11. Do drops really matter? Yes. Antibiotics reduce infection risk and steroids control inflammation to protect the graft. (Standard cornea guidance)

12. Is there any role for “stem-cell eye pills”? No approved oral “stem-cell” products exist for TKP outcomes. Avoid unproven products. (Regulatory reality)

13. What if I have herpetic eye disease? Your team may add antiviral prophylaxis to protect the graft. (Herpetic cornea protocols)

14. Can blood-derived tears help if my surface won’t heal? In selected cases, AS or PRP drops can aid epithelial healing under specialist supervision. PubMed

15. What if I develop severe surface numbness (neurotrophic keratitis)? Cenegermin (rhNGF) can be considered; it’s an FDA-approved topical biologic for that condition. NCBI

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

Last Updated: August 28, 2025.