Infection after radial keratotomy

Fusarium Keratitis: A Systematic Review (1969 to 2023)

BACKGROUND

Mycotic keratitis (MK) represents a corneal infection, with Fusarium species identified as the leading cause. Fusarium is a genus of filamentous fungi commonly found in soil and plants. While many Fusarium species are harmless, some can cause serious infections in humans and animals, particularly Fusarium keratitis, that can lead to severe ocular infections, prevalent cause of monocular blindness in tropical and subtropical regions of the world. Due to its incidence and importance in ophthalmology, we conducted a systematic analysis of clinical cases to increase our understanding of Fusarium keratitis by gathering clinical and demographic data.

METHODS

To conduct an analysis of Fusarium keratitis, we looked through the literature from the databases PubMed, Embase, Lilacs, and Google Scholar and found 99 papers that, between March 1969 and September 2023, corresponded to 163 cases of Fusarium keratitis.

RESULTS

Our analysis revealed the Fusarium solani species complex as the predominant isolate, with females disproportionately affected by Fusarium keratitis. Notably, contact lens usage emerged as a significant risk factor, implicated in nearly half of cases. Diagnosis primarily relied on culture, while treatment predominantly involved topical natamycin, amphotericin B, and/or voriconazole. Surprisingly, our findings demonstrated a prevalence of cases originating from the United States, suggesting potential underreporting and underestimation of this mycosis in tropical regions. This shows the imperative for heightened vigilance, particularly in underdeveloped regions with substantial agricultural activity, where Fusarium infections may be more prevalent than currently reported.

CONCLUSION

Our study sheds light on the clinical complexities of Fusarium keratitis and emphasizes the need for further research and surveillance to effectively tackle this vision-threatening condition. Furthermore, a timely identification and early initiation of antifungal treatment appear to be as important as the choice of initial treatment itself.

Case Report: Corneal Coinfection with Fungus and Amoeba: Report of Two Patients and Literature Review

We report two cases of corneal coinfection with Acanthamoeba and Fusarium sp. along with the review of published literature. A 35-year-old woman and 65-year-old man presented to the institute with corneal ulcer refractory for treatment with topical antibiotics. Microbiological examination revealed the presence of Acanthamoeba cysts along with septate, hyaline fungal filaments. After emergency therapeutic penetrating keratoplasty (TPK) in both, the corneal tissue was sent for histopathologic examination, which confirmed the presence of Acanthamoeba and fungal coinfection. One patient had a recurrence of fungal infection after TPK. In subjects with a rapid progression of mycotic ulcer, coinfection with other microorganisms including Acanthamoeba should be suspected. The two cases presented here emphasize the importance of microbiology in making prompt diagnosis and appropriate management of these cases at an early stage.

Candida albicans keratitis modified by steroid application

The paper reports on Candida albicans ocular infection modified by steroid eye drops. A 74-year-old male complained of conjunctival injection and pain in his right eye three months after pterygium and cataract surgery. After treatment with antibiotics and steroid eye drops for three days, he was referred to our hospital. Clear localized corneal endothelial plaque with injection of ciliary body was observed. No erosion of the corneal epithelium, or infiltration of stromal edema was observed, suggesting that the pathological organism derived from the intracameral region. Because ocular infection was suspected, steroid eye drops were stopped, which led immediately to typical infectious keratitis in the pathological region, with epithelial erosion, fluffy abscess, stromal infiltration, and edema. For diagnostic purposes, the plaque was surgically removed with forceps and the anterior chamber was irrigated with antibiotics. The smear and culture examination from the plaque revealed C. albicans surrounded by neutrophils. However, aqueous fluid and fibrous tissue after gonio procedure contained no mycotic organisms. Topical fluconazole, micafungin, and pimaricin with oral itraconazole (150 mg/day) were effective. Special attention is needed when prescribing steroid eye drops to treat corneal disease especially postoperatively. Diagnosing infectious keratitis is sometimes difficult because of modification by some factors, such as postoperative conditions, scarring, and drug-induced masking. Here, we report on mycotic keratitis modified by postoperative steroid administration.

[Severe infectious keratitis in renal transplant patient: a case report]

Keratitis occurring in renal transplant patients are often severe, with difficult management. We describe the case of a renal transplant patient, 44 year-old man, with history of recurrent herpetic keratitis, which developed an impending corneal perforation. Conjunctival smear showed the presence of amoebic cysts. Anti-amoebic treatment was undertaken in addition with oral aciclovir, and a therapeutic penetrating keratoplasty was performed. An ulceration of the graft occurred within five months. Ocular samples showed the presence of Candida albicans. Despite aggressive antifungal therapy, he required a second therapeutic penetrating keratoplasty for graft perforation. One month later, we noted a recurrence of the ulcer with corneal thinning which evolved to perforation.

Medical treatment for combined Fusarium and Acanthamoeba keratitis

PURPOSE

Acanthamoeba and fungal keratitis are rare ocular infections. We report cases of combined Fusarium and Acanthamoeba keratitis and the clinical course of medical treatment.

METHODS

We reviewed the medical records of patients treated for culture-proven Acanthamoeba keratitis at a referral centre, during 2001-2006.

RESULTS

Eleven consecutive patients were treated for culture-proven Acanthamoeba keratitis during the 5 years, two of whom had combined fungal infections. A 29-year-old man presented with ground-glass corneal oedema and epitheliopathy caused by contact lens use. The other patient, a 7-year-old girl, had eye trauma that led to a feathery corneal infiltrate. Both cases were treated with topical 0.02% polyhexamethylene biguanide (PHMB), 0.1% propamidine, 1% clotrimazole and 5% natamycin. Therapeutic keratoplasty was not required in either case.

CONCLUSIONS

Timely identification of the pathogen, with repeated culture and smear if necessary, as well as adequate dosage to prevent recurrence is highly recommended in order to preclude the need for therapeutic penetrating keratoplasty.

A return to primitive practice? Radial keratotomy revisited

Recently, a refractive surgeon was quoted in the national and professional press as proposing that radial keratotomy (RK) is to be preferred over laser procedures, such as photorefractive keratectomy (PRK) and laser assisted in situ keratomileusis (LASIK). The rationale for this public recommendation was that the RK procedure achieves better visual results and fewer complications than the laser procedures. Peer reviewed literature on these refractive procedures was surveyed to establish the validity of such a statement and it was found that current data do not support the notion that RK results in better visual outcomes than PRK and LASIK The true incidence of complications is difficult to establish. However, when the post procedure chronic effects are compared between RK, PRK and LA SIK, it becomes apparent that the post-RK patient pays the highest price, by a large margin, in visual quality impairment and corneal health. Although the visual acuity outcomes for low to moderate myopes, when corrected by any of the three refractive procedures considered here, are not dramatically different, we concluded that RK is not the preferred methodology because of its associated chronic visual and corneal health complications.

Acanthamoeba keratitis associated with fungal keratitis

PURPOSE

To report fungal infection complicating Acanthamoeba keratitis.

METHODS

Case report. A 45-year-old woman with contact lens-related bilateral Acanthamoeba keratitis developed corneal ulcer, corneal perforation, and mature cataract in the left eye, which was managed by penetrating keratoplasty, lensectomy, and vitrectomy.

RESULTS

Histopathologic examination of the keratoplasty specimen from the left eye revealed extensive lamellar stromal necrosis with the coexistence of both empty cysts and branching hyphae. Cultures from the keratoplasty specimen grew Scedosporium apiospermum.

CONCLUSION

Keratomycosis caused by S. apiospermum may complicate protracted Acanthamoeba keratitis.

Corneal co-infection with Scedosporium apiospermum and Acanthamoeba after sewage-contaminated ocular injury

PURPOSE

To describe a corneal co-infection with the fungus Scedosporium apiospermum and Acanthamoeba that result in spontaneous corneal perforation.

METHODS

A 27-year-old man presented due to severe ocular pain in his left eye caused by a corneal ulcer. The patient was injured 7 days before presentation by metallic thread contaminated by sewage. Corneal scrapping and deep stromal biopsy were obtained and stained for microscopic evaluation with periodic acid-Schiff, Giemsa, and Gomori's methenamine silver stains. Samples were sent for aerobic and anaerobic bacterial and fungal cultures.

RESULTS

Corneal biopsy and corneal scrapping showed viable Acanthamoeba cysts in the corneal stroma and S. apiospermum micelle, respectively. The fungal culture was sensitive to ketoconazole, miconazole, econasole, and traconazole. Devastating corneal perforation occurred despite aggressive antifungal and antiamoebic topical and systemic treatment initiated after diagnosis. The corneal button showed a necrotic tissue devoid of inflammatory cells and microorganisms.

CONCLUSION

S. apiospermum and Acanthamoeba may co-infect immune privilege sites, such as the cornea, in immunocompetent hosts. Compromised corneal surface, e.g., after trauma by sewage-contaminated objects, may increase the susceptibility for such devastating coinfection. Prevention may be possible by use of protective eyewear by high-risk individuals. Treatment should be initiated promptly with broad-spectrum antimicrobial agents after ocular injury by sewage-contaminated objects. Repeated corneal cultures and biopsies, if the cultures are negative, are warranted. Corticosteroids should be withheld until the causative agents are identified and targeted treatment is initiated.

Postoperative Inflammation, Microbial Complications, and Wound Healing Following Laser in situ Keratomileusis

Although the biology of corneal wound healing is only partly understood, healing after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) differs in many respects, and the mechanisms appear to be differently controlled. There is less of an inflammatory and healing response after LASIK, but a longer period of sensory denervation. The cellular, molecular, and neural regulatory phenomena associated with postoperative inflammation and wound healing are likely to be involved in the adverse effects after LASIK, such as flap melt, epithelial ingrowth, and regression. Interface opacities in the early postoperative period include diffuse lamellar keratitis (DLK), microbial keratitis, epithelial cells, and interface opacities. Diffuse lamellar keratitis (sands of the Sahara syndrome) describes an apparently noninfectious diffuse interface inflammation after lamellar corneal surgery probably caused by an allergic or a toxic inflammatory reaction. Noninfectious keratitis must be distinguished from microbial keratitis to avoid aggressive management and treatment with antimicrobial drugs. Microbial keratitis is a serious complication after LASIK, but a good visual outcome can be achieved following prompt and appropriate treatment.

Nocardia Keratitis After Traumatic Detachment of a Laser in situ Keratomileusis Flap

PURPOSE

Nocardia are gram-positive bacteria existing ubiquitously in the environment; they can cause keratitis. Nocardia asteroides keratitis occurred in the interface between the stromal bed and flap after traumatic detachment of the flap 4 months after an initially uncomplicated laser in situ keratomileusis (LASIK) procedure.

METHODS

Nocardia asteroides keratitis was confirmed by culture. Therapy included topical and oral trimethoprim-sulfamethoxazole.

RESULTS

Thirteen months after the trauma, the patient's spectacle-corrected visual acuity was 20/20 with a manifest refraction of -2.25 -1.00 x 30 degrees.

CONCLUSIONS

The immediate steps of management consisting of surgically lifting the corneal flap, rapid microbial identification, and proper treatment with specific antibiotics resulted in the successful treatment of Nocardia asteroides keratitis in a traumatized eye after LASIK.

Early- versus late-onset infectious keratitis after radial and astigmatic keratotomy: clinical spectrum in a referral practice

PURPOSE

To compare the clinical characteristics of early- versus late-onset keratitis after radial keratotomy (RK) and astigmatic keratotomy (AK).

SETTING

Referral subspecialty practice.

METHODS

This retrospective review comprised 19 patients with infectious keratitis after RK and AK. Early- versus late-onset groups were analyzed for predisposing conditions; infiltrate location, size, and depth; microbiologic data; and final visual outcome.

RESULTS

Ten patients in the early-onset group developed keratitis within a mean of 7.4 days after surgery (range 3 to 14 days). Nine patients in the late-onset group developed keratitis a mean of 5.4 years after surgery (range 1.5 to 15.0 years). Staphylococcus aureus was the predominant organism in the early-onset group and Pseudomonas aeruginosa in the late-onset group. In the early-onset group, most infiltrates occurred in the paracentral aspect of the RK incision and extended to the middle or posterior stroma. In the late-onset group, most infiltrates occurred in the peripheral portion of the RK incision and were localized to the superficial stroma. A hypopyon was present in 7 of 10 ulcers in the early group and in 1 of 9 in the late group. Two patients in the early group developed endophthalmitis. Most patients in the late-onset group had incisional pseudocysts; 2 had other risk factors for keratitis. Final visual acuity was 20/40 or better in 7 of 10 patients in the early group and in 8 of 9 patients in the late group.

CONCLUSIONS

Early-onset corneal ulcers after incisional refractive keratotomy were usually paracentral and deep, whereas late-onset ulcers were usually peripheral and superficial. Despite the predominance of Staphylococcus and Pseudomonas in the early- and late-onset groups, respectively, a variety of organisms may be responsible for infections in keratotomy incisions.

Keratitis complicated by endophthalmitis 3 years after astigmatic keratotomy

Endophthalmitis after keratotomy is rare and usually occurs soon after surgery. A 56-year-old woman with mild dry-eye symptoms developed keratitis complicated by endophthalmitis 3 years after astigmatic keratotomy (AK). The keratitis lasted for less than 1 day in the upper keratotomy incision. Corneal cultures yielded. Pseudomonas aeruginosa. Keratitis progressed to endophthalmitis 1 day after the detection of keratitis. The inflammation was controlled with intravitreal, subconjunctival, topical, and systemic antibiotics. This case demonstrates the potential risk of endophthalmitis developing very shortly after late keratitis of AK incisions. Vigorous early treatment and close follow-up seem justifiable in any keratitis associated with a keratotomy incision.

Acanthamoeba keratitis

Acanthamoeba species are an important cause of microbial keratitis that may cause severe ocular inflammation and visual loss. The first cases were recognized in 1973, but the disease remained very rare until the 1980s, when an increase in incidence mainly associated with contact lens wear was reported. There is an increased risk when contact lens rinsing and soaking solutions are prepared with nonsterile water and salt tablets. The clinical picture is often characterized by severe pain with an early superficial keratitis that is often treated as herpes simplex infection. Subsequently a characteristic radial perineural infiltration may be seen, and ring infiltration is common. Limbitis and scleritis are frequent. Laboratory diagnosis is primarily by culture of epithelial samples inoculated onto agar plates spread with bacteria. Direct microscopy of samples using stains for the cyst wall or immunostaining may also be employed. A variety of topically applied therapeutic agents are thought to be effective, including propamidine isethionate, clotrimazole, polyhexamethylene biguanide, and chlorhexidine. Various combinations of these and other agents have been employed, often resulting in medical cure, especially if treatment is commenced early in the course of the disease. Penetrating keratoplasty is preferably avoided in inflamed eyes, but may be necessary in severe cases to preserve the globe or, when the infection has resolved, to restore corneal clarity for optical reasons.

Corneal infection after radial keratotomy

PURPOSE

To evaluate nine eyes that developed corneal infection after radial keratotomy (RK) and their subsequent management.

SETTING

Dr. Rajendra Prasad Centre for Ophthalmic Sciences, New Delhi, India.

METHOD

The parameters evaluated were interval between RK and development of the ulcer, number of keratotomy incisions, nature of surgery (primary or secondary), status at presentation, and best corrected visual acuity (BCVA). Corneal scrapings were taken from all eyes for microbiological evaluation. Initial therapy was based on clinical impression and subsequent therapy, on the microbiological report.

RESULTS

Staphylococcus species were the most frequently isolated bacteria followed by Pseudomonas aeruginosa. Two eyes had fungal growth, and no organisms were isolated from one. All but one eye responded to medical therapy; healing took 23 to 26 days. Therapeutic penetrating keratoplasty (PKP) was done in one eye. Presenting BCVA of hand movement to 6/36 improved to hand movement to 6/18 after the ulcer healed. Final BCVA was 6/36 to 6/9 after lamellar keratoplasty or PKP or with contact lens of spectacle correction.

CONCLUSION

Our study shows that corneal infection is a potential complication of RK. Therefore, persistent postoperative irritation should be carefully observed to ensure early diagnosis and prompt therapy.

Nocardial Keratitis after Laser in situ Keratomileusis

PURPOSE AND METHODS

Corneal interface central nodules appeared in a patient who underwent uncomplicated laser in situ keratomileusis (LASIK) retreatment for residual myopia.

RESULTS/CONCLUSIONS

Nocardia asteroides keratitis was confirmed by microbiologic studies, which guided treatment. Six months after the appearance of the keratitis, the patient's uncorrected visual acuity was 20/45, and spectacle-corrected visual acuity was 20/40. The postoperative refraction was +0.75 -0.75 X 95 degrees, and slit-lamp examination revealed a clear cornea with a mild rounded scar in the central area. Night halos and starbursts were the main complaints in this patient. The immediate management of lifting the corneal flap for stromal bed scraping, fast microbial identification, and proper treatment was the key for the results in this patient.

Acanthamoeba infection after radial keratotomy

PURPOSE

To describe a case of Acanthamoeba infection of the cornea after radial and astigmatic keratotomy.

METHODS

A 29-year-old man developed ulcerative keratitis in the right eye 6 weeks after uncomplicated radial and astigmatic keratotomy.

RESULTS

Three sets of corneal cultures for bacteria and fungi were negative. Culture on non-nutrient agar grew Acanthamoeba organisms. Clinical improvement occurred after topical antiamebic therapy was instituted.

CONCLUSIONS

Incisional keratotomy may predispose the cornea to delayed-onset infectious keratitis. Acanthamoeba should be considered as a possible cause of infection and should be cultured for in refractory cases.