Postoperative Corneal Melt Clinical Presentation

Updated: Aug 29, 2019
  • Author: Arun Verma, MD; Chief Editor: Hampton Roy, Sr, MD  more...
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Presentation

History

Postoperative corneal melt can occur with almost all the intraocular operations. The major operations are listed below.

Pterygium excision

Corneal melts can infrequently follow a routine surgical removal of pterygium. Postoperative corneal melts have been seen in 2 apparently healthy young patients within 2 weeks of routine excision of the pterygia. No evident predisposing factors were present in one patient (a male aged 28 y), whereas the other patient (a female aged 38 y) had rheumatoid disease.

A 59-year-old man underwent pterygium excision with intraoperative application of 0.2 mg/mL (0.02%) mitomycin-C placed on the scleral bed for 3 minutes. A sliding conjunctival flap was used to cover the exposed limbus and sclera. Five weeks after the original surgery, the patient had mild trauma and noted decreased vision. At that time, it was noted that he had a corneoscleral melt with perforation. The patient was treated with a lamellar transplant in this area.

Intraoperative single-dose application of topical mitomycin-C can be associated with serious complications. A detailed report with serious, vision-threatening complications associated with mitomycin-C use after pterygium surgery has been published. The complications included iritis, severe secondary glaucoma, corneal edema, corectopia, sudden-onset mature cataracts, scleral calcification, and corneal melt leading to perforation.

A separate case report describes a 36-year-old woman who had a corneal infiltrate, corneoscleral ulceration, a pupil peaked toward the ulceration (globe perforation not mentioned), hypotony, vitreous exudates, optic disc hyperemia, and macular edema after using 0.2 mg/mL of mitomycin-C 3 times daily for 3 weeks after pterygium surgery. Although topical mitomycin-C is effective as an adjunct to pterygium surgery and may reduce recurrence, the safety and efficacy of various concentrations and dosing schedules need further definition.

Beta radiation after surgical removal of pterygia: Among the less commonly reported complications of beta radiation treatment after pterygium removal are ptosis, iris atrophy, corneal ulceration, bacterial corneoscleritis, and fungal panophthalmitis. Mitomycin-C and beta radiation must be used with caution, knowing that complications may occur months to years later. Future studies may elucidate the cause of these delayed complications and allow better selection of adjunctive therapy after pterygium surgery.

Corneal refractive surgery including radial keratotomy

Serious complications can occur following radial keratotomy procedure. Bacterial keratitis with corneal melting has been reported in the early postoperative periods. Most of the infections are located in the inferior portions of the cornea within the incision sites. Cottinger et al believe that the delayed infections were secondary to epithelial erosions and dry eye tendencies. [1]

In cases where rheumatoid arthritis only manifests in the joints, patients usually do very well with LASIK. According to Maloney, corneal melting is very unusual in a patient without extra-articular disease, though such cases may occur; he cites a study published by Foster and colleagues that showed that corneal melting following cataract surgery could be the first manifestation of extra-articular disease.

These rare cases tend to happen in much older patients. Also, they almost always occur in patients where the disease is active and not well controlled. In general, the patients undertaken for LASIK should be relatively young, with well-controlled disease and good tear function. Consultation with the patient’s rheumatologist is recommended to ensure the disease is well controlled. Patients themselves can also be helpful in this regard.

Enbrel (etanercept) and other immune response modulators are also making LASIK more viable in these patients. This new class of drug has revolutionized the treatment of rheumatoid arthritis. As a result of these new medications, the disease is less damaging and far better controlled than it was a decade or two ago.

Proper informed consent is also crucial before allowing any patient with an autoimmune disorder to undergo LASIK. Many surgeons consider the disease to be a contraindication for LASIK due to the potential for corneal melting.

While LASIK can be a good bet for many of these patients, the study results should by no means be extrapolated to photorefractive keratectomy (PRK). According to Maloney, PRK may be less safe than LASIK in these cases. PRK creates a large epithelial defect. Because nonhealing epithelial defects cause ulceration, there is the concern that such epithelial defects may predispose these patients to ulceration. [2]

The study results also have no bearing on whether or not such patients are at increased risk of dry eye. A prospective study would be needed.

Patients can present with symptoms of recurrent erosions. Most likely, an epithelial plug surfaces from the radial incision, is traumatically ruptured, and becomes secondarily infected. Similarly, epithelial cysts rupture spontaneously in the postoperative period leading to stromal inflammation and this may be the pathogenesis of corneal ulcers and melts. Wounds tend to heal slower and gape more when a radial incision bisects a transverse or circumferential incision, which also can contribute to postoperative corneal melting syndrome.

Anterior corneal epithelial basement membrane changes, similar to those seen in epithelial basement membrane dystrophy, often are observed after radial keratotomy (RK). These changes tend to be transient, lasting less than 3 months in most eyes. They infrequently are associated with clinical symptoms or recurrent epithelial erosion.

A most unusual complication of refractive keratotomy is the late development of bacterial and fungal ulcerative keratitis. All infiltrates are noted to be contiguous with the keratotomy scars. The persistent epithelial plug in the keratotomy wound is implicated in delayed bacterial and fungal keratitis, leading to postoperative corneal melting.

Epikeratophakia

Failure of epikeratoplasty procedures because of postoperative corneal melts and perforation has been reported. The common suggestion is that the presently used process of tissue preparation may be deleterious to the structure of the donor lenticule and may adversely affect surface reepithelialization. The placement of the lenticule above the recipient's Bowman layer may be an additional retardant to postoperative reepithelialization.

Keratomileusis

A few resurfacing problems have been reported after keratomileusis procedure for myopia. Patients can develop nonhealing epithelial defect leading to corneal ulceration and corneal melt.

Excimer laser PRK and LASIK surgery

Absolute contraindication for photorefractive excimer and LASIK lasers would be rheumatoid diseases because of potential corneal melting ulcers. Patients can develop extensive epithelial ingrowth and keratolysis along with stromal melts. This complication can be treated by lifting the flap and removing the epithelium from the interface.

LASIK: Corneal melting ulceration and fine striaelike infiltrates were noticed 1 day postoperatively. No response occurred to intensive topical antibiotic in the form of hourly ofloxacin 3%, and satellite lesions developed on day 4. No bacterial or fungal organisms were identified. Intensive fortified vancomycin (50 mg/mL) was added. Complications at 6 months included epithelial ingrowth, corneal flap melting, and decentered ablation.

Progressive keratolysis (stromal melt) can result in irregular astigmatism, photophobia, ciliary injection, and loss of vision. The pathogenesis is not completely understood, although the epithelial ingrowth in the interface is always present and epithelial stromal interaction with production of proteases may be involved. Epithelial ingrowth may develop in the lamellar interface after LASIK and may be associated with melting of the edge of the flap.

Keratoplasty

Epithelial problems after penetrating keratoplasty include defects secondary to cell loss during or after surgery, epithelial irregularity and superficial punctate keratopathy secondary to an inadequate tear film, localized trauma from aberrant eyelashes or eyelid scarring, and delayed or poor healing secondary to toxic keratitis medicamentosa from topical drops. Persistent epithelial defects increase the chances of graft infection, corneal melting, and failure.

Infectious crystalline keratopathy is a serious, nonsuppurative, bacterial infection of the graft that may occur in patients maintained on chronic topical corticosteroids. Several different organisms, with Streptococcus viridans and anaerobic bacteria being the most frequent isolates, cause this infection. Culture results often are negative; therefore, corneal biopsy for histologic examination and microbiologic evaluation is recommended for accurate diagnosis.

Epithelial irregularity or haziness secondary to chronic ocular surface disease, such as keratoconjunctivitis sicca or blepharitis, can cause decreased vision and may put the eye at risk of other problems such as infectious keratitis, corneal melting, or stromal scarring.

Keratoprosthesis

In any design in which the keratoprosthesis is anchored exclusively to the cornea, conjunctiva often grows across the keratoprosthesis or retracts, causing corneal melting. A high rate of spontaneous extrusion occurs. Keratoprosthesis may be associated with early or delayed corneal melting. [3, 4]

Glaucoma surgeries

Routine filtration operation and filtration operation performed in conjunction with subconjunctival injection of 5-FU

Corneal and conjunctival epithelial toxicity, manifested as punctate epithelial erosions, corneal epithelial defects, and primary conjunctival wound leaks, is the most common complication of postoperative subconjunctival 5-FU injection. Epithelial defects, leading to corneal thinning and ultimately late corneal melts also can occur.

Eyes with limited limbal stem cells populations, such as those with Stevens-Johnson syndrome, pseudopemphigoid, and alkali injury should not receive 5-FU for fear of permanently reducing the limbal stem cell pool. Presence of preexisting corneal epithelial edema, a risk factor for the development of corneal epithelial defects, also has been associated with serious bacterial corneal infections, thinning, and corneal melting in eyes that received 5-FU after filtration surgery.

Routine filtration operation performed in conjunction with topical mitomycin

Routine filtration surgery along with the use of topical mitomycin-C also can cause postoperative corneal melts, although the incidence reported is not very high.

Trabeculectomy and trabeculectomy using local mitomycin drops

Corneal melt has been reported with Molteno shunt valve operation. After blunt trauma, the secondary plate of a double-plated Molteno implant became completely dislodged anteriorly onto the patient's cornea. The corneal tissue entrapped beneath the avulsed plate was found to have extensive melting requiring emergency explantation of the Molteno implant and corneal grafting.

Progressive postoperative corneal melt has been reported after Nd:YAG or argon therapy. Postoperative corneal ulcers have been reported with argon laser trabeculoplasty.

Transscleral cyclophotocoagulation (TSCPC): TSCPC infrequently can cause corneal epithelial defects leading to postoperative corneal melts. This can be prevented by use of contact lens during noncontact Nd:YAG cyclophotocoagulation.

Pulsed dye sclerostomy: The most common complication of this procedure includes localized corneal edema with peripheral melts adjacent to the sclerostomy site. The debate continues over whether the thermal effects are beneficial or detrimental to the scleral collagen and the corneal collagen. This controversy will be resolved once appropriate laser systems are available. The most common complication of Nd:YAG ab interno laser sclerostomy includes ruptured blebs and corneal stromal and epithelial melts. Nd:YAG cyclophotocoagulation reduces this complication.

Vitrectomy (intraoperative corneal complication)

The corneas of diabetic patients are vulnerable to recurrent erosion. Therefore, prior to and during surgery, every effort should be made to avoid corneal trauma. In the immediate preoperative period, corneal contact such as tonometry, contact lens examinations, and electroretinography, should be minimized. The cornea must not be touched by solutions used for sterile preparation of the operative field. During the vitrectomy, the cornea must be moistened frequently. Despite these measures, the epithelium of diabetic patients is much more likely to become opaque during vitrectomy than is that of nondiabetic patients.

Diabetes mellitus predisposes to these complications for 2 reasons. First, diabetic corneas have slightly decreased sensation; therefore, a neurotrophic component may contribute to their intraoperative and postoperative complications. Second, the adhesion between the epithelium and the stroma is abnormally weak in diabetic patients. Indeed, the epithelium in diabetic patients can be brushed off easily with a cotton-tipped applicator, whereas that of nondiabetic patients must be removed with a scalpel. Intraocular irrigating solutions are toxic to the corneal endothelium.

Formerly, as many as 15% of diabetic patients had significant postoperative corneal decompensation, infections, and melts. As many as 3% required a corneal transplant. More recent studies show a marked decrease in corneal complications.

Vitreous surgery

Keratopathy (eg, epithelial or stromal edema, band or bullous keratopathy) is another frequent problem after vitreous surgery for severe proliferative vitreoretinopathy (PVR). In phase 2 of the Silicone Study, in group 1, 33% of eyes that received C3 F8 and 30% of those that received silicone oil developed keratopathy by the last follow-up examination. In group 2, an even higher prevalence of keratopathy was noted with 45% of eyes receiving C3 F8 eyes and 43% of eyes receiving silicone oil noted to have developed keratopathy by the last follow-up visit. As expected, keratopathy was much more frequent in eyes in which anatomic reattachment failed.

Scleral buckling

Scleral buckling operation for detached retina can cause postoperative corneal or scleral melt from an encircling band or a circumscribed buckle.

Corneal clouding

During scleral buckling procedures, adequate visualization throughout the case is critical to the success of the operation. Corneal clouding is a common intraoperative problem. This usually is caused by epithelial edema from increased intraocular pressure, which occurs during scleral depression. The epithelium also may become damaged by desiccation or mechanical trauma during the procedure. Mild amounts of epithelial edema may be resolved with topical glycerine or by rolling the epithelium with a dry cotton-tipped applicator. Extensive epithelial edema usually requires debridement with a rounded blade. The debrided epithelial cells are removed with a cellulose sponge to prevent dispersion, which may result in epithelial inclusion cysts. These in turn may cause postoperative corneal melts.

Pars plana vitrectomy

Rubeosis and endophthalmitis have occurred in less than 0.5% of cases. Rarely, late corneal complications in the form of peripheral melts have been reported. Peripheral melts also can occur after penetrating keratoplasty operation, especially in those patients receiving antiglaucoma drugs, most of which are toxic to the cornea and promote an inflammatory response postkeratoplasty. The surgeon should control intraocular pressure before keratoplasty, with a filtration operation, if necessary.

Cataract

Central sterile corneal ulceration and melting has been reported days to weeks after otherwise unremarkable cataract surgery in patients who have rheumatoid arthritis with keratoconjunctivitis sicca. [5]

Phaco surgery (retained lens material causing corneal problems): One third to one half of eyes with sufficient retained lens fragments considered for vitrectomy present with some degree of corneal decompensation. In most cases, this is transient keratopathy and probably reflects the trauma of the cataract surgery and an increase in intraocular pressure. In approximately 10% of patients (20-30% of those eyes presenting with keratopathy), corneal edema will persist, resulting in bullous keratopathy and often requiring keratoplasty. Postoperative corneal ulcers and melts also have been reported. Postoperative use of nonsteroidal anti-inflammatory drops also has been implicated in sterile corneal melts after cataract surgery.

Rectus muscle surgery

Rectus muscle surgery is rare cause of postoperative corneal melt.

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Physical

Physical findings can range from very mild, which may mimic keratoconjunctivitis, to severe, with ring infiltration and descemetocele formation and perforation. Postoperative corneal melt can be confused in its early phases with simple keratitis and may even coexist with bacterial or viral keratitis. Ophthalmologists must maintain a high index of suspicion for this condition. Postoperative corneal melt typically follows exposure of an epithelially compromised cornea to a contaminated source. Epithelial compromise includes all the previously described conditions and procedures, epithelial disease such as dry eye, and ocular injuries such as abrasions or foreign bodies.

Corneal refractive surgery radial keratotomy

Serious complications can occur following radial keratotomy procedure. There have been reports of bacterial keratitis with corneal melting in the early postoperative periods. Most of the infections are located in the inferior portions of the cornea, within the incision sites. Cottinger et al believe that the delayed infections were secondary to epithelial erosions and dry eye tendencies. [1]

Patients can present with symptoms of recurrent erosions. Most likely, an epithelial plug surfaces from the radial incision, is traumatically ruptured, and becomes secondarily infected. Similarly epithelial cysts rupture spontaneously in the postoperative period leading to stromal inflammation; this may be the pathogenesis of corneal ulcers and melts. Wounds tend to heal slower and gape more when a radial incision bisects transverse or circumferential incision, which can contribute to postoperative corneal melting syndrome.

Anterior corneal epithelial basement membrane changes, similar to those seen in epithelial basement membrane dystrophy, often are observed after RK. These changes tend to be transient, lasting less than 3 months in most eyes. They infrequently are associated with clinical symptoms or recurrent epithelial erosion.

A most unusual complication of refractive keratotomy is the late development of bacterial and fungal ulcerative keratitis. All infiltrates are noted to be contiguous with the keratotomy scars. The persistent epithelial plug in the keratotomy wound is implicated in delayed bacterial and fungal keratitis, leading to postoperative corneal melting. Corneal melting ulceration and fine striaelike infiltrates were noticed 1 day postoperatively.

Complications at 6 months included epithelial ingrowth, corneal flap melting, and decentered ablation. Progressive keratolysis (stromal melt) can result in irregular astigmatism, photophobia, ciliary injection, and loss of vision. The pathogenesis is not completely understood, although the epithelial ingrowth in the interface is always present and epithelial stromal interaction with production of proteases may be involved. Epithelial ingrowth may develop in the lamellar interface after LASIK and may be associated with melting of the edge of the flap.

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Causes

See the list below:

  • Skin conditions

    • Herpes zoster

    • Incontinentia pigmenti (Block-Sulzberger syndrome)

    • Lichen planus

    • Molluscum contagiosum

    • Palmoplantar keratosis

    • Pityriasis rubra pilaris

    • Psoriasis

    • Acne rosacea

    • Benign mucosal pemphigoid

    • Dermatitis herpetiformis

    • Leprosy

    • Lyell disease (toxic epidermal necrolysis or scalded skin syndrome)

    • Lymphopathia venereum

    • Pemphigus foliaceus (Cazenave disease)

    • Ectodermal dysplasia (anhidrotic)

    • Ichthyosis

  • Vitamin deficiency

    • Ariboflavinosis keratopathy

    • Vitamin A deficiency

    • Vitamin B-2 deficiency (Addison pernicious anemia syndrome)

    • Pellagra (avitaminosis B-2)

  • Collagen disorders

    • Polyarteritis nodosa (Kussmaul disease)

    • Rheumatoid arthritis (Sjögren syndrome, secretoinhibitory syndrome)

    • Scleroderma (progressive systemic sclerosis)

    • Systemic lupus erythematosus (Kaposi-Libman Sacks syndrome)

  • Systemic diseases

    • Tuberculosis (scrofulous keratitis)

    • Upper respiratory infection

    • Gout

    • Vaccinia

    • Haemophilus influenzae

    • Hypoparathyroidism

    • Leprosy (Hansen disease)

    • Lymphopathia venereum

    • Deerfly fever (tularemia)

    • Mumps

    • Brucellosis

    • Trypanosomiasis

    • Filariasis

    • Hodgkin disease

    • Sarcoidosis

  • Drugs

    • Steroid therapy

    • Topical anesthesia abuse

    • Stevens-Johnson syndrome (erythema multiforme exudativum)

    • Topical nonsteroidal anti-inflammatory agents

  • Ocular predisposing factors

    • Phlyctenular keratoconjunctivitis

    • Superior limbic keratoconjunctivitis (micropannus)

    • Trachoma

    • Terrien disease (senile marginal atrophy)

    • Vernal conjunctivitis

  • Preexisting corneal dellen plays an important role in postoperative corneal melting. Dellen can develop in the following:

    • Following wearing of contact lenses

    • Limbal vasosclerosis (elderly patients)

    • Lagophthalmos

    • Lengthy administration of cocaine

    • Postcataract section

    • Swelling of perilimbal tissues

    • Allergic conjunctival edema

    • Episcleritis

    • Filtering blebs

    • Limbal tumor

    • Postoperative advancement of rectus muscle

    • Postoperative retinal detachment

    • Pinguecula

    • Subconjunctival effusion or injection with hemeralopia

  • Delayed corneal wound healing followed by corneal melting may occur because of the following drugs:

    • Adenine arabinoside

    • Adrenal cortex injections

    • Aldosterones

    • Alpha-chymotrypsin

    • Azathioprine

    • Betamethasone

    • Butacaine

    • Cocaine

    • Cortisone

    • Dexamethasone

    • Fluorometholone

    • Fluprednisolone

    • Hydrocortisone

    • Prednisolone

    • Sulfacetamide

    • Sulfamethizole

    • Tetracaine

    • Triamcinolone

  • Marginal ring ulcers/melts may occur in the following:

    • Acute leukemia

    • Bacillary dysentery

    • Brucellosis

    • Dengue fever

    • Gonococcal arthritis

    • Hookworm infestation

    • Influenza

    • Possibly porphyria trigger mechanisms

  • Acquired immunodeficiency syndrome (AIDS): Culture-negative peripheral corneal melting has been observed in a patient with AIDS.

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Complications

Complications include infection, bleeding, endophthalmitis, severe visual loss, and blindness.

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