Treatment Failure after Lamellar Keratoplasty for Fungal Keratitis

Frequency and Outcome of Emergency Penetrating Keratoplasty in Infectious Keratitis in Sweden During the 21st Century

PURPOSE

To study the frequency over time and outcome of penetrating keratoplasty (PK), "keratoplasty à chaud," in patients with infectious keratitis with 2-year follow-up data.

METHODS

This register-based study included keratitis cases that had undergone PK in Sweden between 2001 and 2020 and reported to the Swedish Corneal Transplant Register.

RESULTS

During the study period, 69 eyes were subjected to acute PK due to progressive infectious keratitis. The number increased from 2 annual procedures in the first half of the study period to 5 in the second half (P = 0.01). Preoperative corneal perforation was present in 43.5% (n = 30) of the eyes. Two years after surgery, follow-up data were completed in the register for 53 eyes; of these, 62.3% (n = 33) were considered to have functioning grafts, and 20.8% (n = 11) had experienced a rejection episode. The visual acuity improved from hand motion to counting fingers (P = 0.002), and the proportion of eyes with a visual acuity of ≤1.0 logMAR increased from 5.7% (n = 3) before the surgery to 45.3% (n = 24) at the 2-year follow-up (P < 0.001).

CONCLUSIONS

The number of active infectious keratitis cases undergoing keratoplasty à chaud increased in Sweden during the 21st century. Most of the cases were successful regarding the structural integrity of the bulb, that is, "had a saved eye" and even a functioning graft 2 years after corneal transplantation. The visual gain was distinct, albeit modest. In cases with severe infectious keratitis, and even a concomitant perforation in the cornea due to the infection, corneal transplantation should continue to be an option.

Differentiation of acanthamoeba keratitis from other non-acanthamoeba keratitis: Risk factors and clinical features

INTRODUCTION

Infectious Keratitis is one of the most common ocular emergencies seen by ophthalmologists. Our aim is to identify the risk factors and clinical features of Acanthamoeba Keratitis (AK).

METHODS

This retrospective chart review study was conducted at King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia, and included all the microbial keratitis cases, male and female patients of all ages. The main outcome is the differentiation between various microbial keratitis types.

RESULTS

We included 134 consecutive eyes of 126 persons. We had 24 cases of acanthamoeba keratitis, 22 bacterial keratitis, 24 fungal keratitis, 32 herpetic keratitis, and 32 bacterial co-infection. Contact lens wear was found in 33 eyes (24.6%). Among acanthamoeba keratitis patients, 73% were ≤ 39 years of age, and 73% were females (P <0.001). Also, in AK cases, epithelial defect was found in all cases (100%), endothelial plaques were found in 18 eyes (69.2%), 12 cases had radial keratoneuritis (46.2%), and ring infiltrate was found in 53.8% of AK cases.

CONCLUSIONS

We determined the factors that increase the risk of acanthamoeba infection and the clinical characteristics that help distinguish it from other types of microbial keratitis. Our findings suggest that younger females and patients who wear contact lenses are more likely to develop acanthamoeba keratitis. The occurrence of epitheliopathy, ring infiltrate, radial keratoneuritis, and endothelial plaques indicate the possibility of acanthamoeba infection. Promoting education on wearing contact lenses is essential to reduce the risk of acanthamoeba infection, as it is the most significant risk factor for this infection.

Nonsurgical Management of Severe Viral Keratitis with Hypopyon and Retrocorneal Plaques: A Case Series

INTRODUCTION

Severe viral keratitis with hypopyon and retrocorneal plaques is easily misdiagnosed as it mimics fungal or bacterial keratitis and is more likely to undergo emergency therapeutic penetrating keratoplasty (TPK) in the presence of active infection, resulting in poor outcomes. This case series offers some important insights for the management strategy of severe viral keratitis.

METHODS

This retrospective case series involved five patients with unilateral severe infectious keratitis with hypopyon over 3 mm and retrocorneal endothelial plaques. Testing for corneal sensation, microscopy, culture, and anterior segment optical coherence tomography (ASOCT) were performed.

RESULTS

At presentation, all five cases had visual acuity of counting fingers (CF) or worse, large centrally located ulcer with clean ulcer surface, hypopyon, and retrocorneal plaques with reduced corneal sensation. ASOCT demonstrated the presence of retrocorneal plaques with clear space between corneal endothelium and plaques. All cases received systemic and topical ganciclovir and topical steroids. Two patients received intravenous immunoglobulin (IVIG) weekly for 2 weeks. Complete resolution was achieved in all cases except one patient who underwent TPK because of diffuse anterior synechiae of the iris, with recurrence of infection after 10 days. The patients who received IVIG showed resolution earlier compared to the other patients.

CONCLUSIONS

Evaluation of characteristics of retrocorneal plaques by ASOCT and reduced corneal sensation are valuable aids in diagnosis of complicated viral keratitis. Conservative medical management may be a viable option even in severe cases. IVIG may have a role in speedy resolution of severe cases, but more research is needed to confirm this.

Management of Filamentous Fungal Keratitis: A Pragmatic Approach

Filamentous fungal infections of the cornea known as filamentous fungal keratitis (FK) are challenging to treat. Topical natamycin 5% is usually first-line treatment following the results of several landmark clinical trials. However, even when treated intensively, infections may progress to corneal perforation. Current topical antifungals are not always effective and are often unavailable. Alternatives topical therapies to natamycin include voriconazole, chlorhexidine, amphotericin B and econazole. Surgical therapy, typically in the form of therapeutic penetrating keratoplasty, may be required for severe cases or following corneal perforation. Alternative treatment strategies such as intrastromal or intracameral injections of antifungals may be used. However, there is often no clear treatment strategy and the evidence to guide therapy is often lacking. This review describes the different treatment options and their evidence and provides a pragmatic approach to the management of fungal keratitis, particularly for clinicians working in tropical, low-resource settings where fungal keratitis is most prevalent.

Outcomes of Severe Fungal Keratitis Using in vivo Confocal Microscopy and Early Therapeutic Penetrating Keratoplasty

Purpose

The purpose of this study was to assess the impact of early diagnosis using in vivo confocal microscopy and early therapeutic penetrating keratoplasty (TPK) on the outcomes of severe cases of fungal keratitis.

Methods

This retrospective single-center study included 38 patients (40 eyes) with fungal keratitis who presented between December 2013 and February 2020. Preoperative, intraoperative, and postoperative parameters were recorded to assess the role of early correct diagnosis and early surgical therapy on visual acuity outcome and enucleation rate during follow-up.

Results

The mean patient age was 51 years (71% females). The initial external diagnosis was correct in 20 cases (50%). The mean time from symptom onset until admission to our department was 46.8 ± 68.0 (median 28.5) days. The mean time to correct diagnosis after admission to our department was 1 day with in vivo confocal microscopy (IVCM). IVCM was performed in 38 cases, of which 36 (sensitivity: 94.7%) were positive for fungal infection. Twenty-seven out of 40 (67.5%) eyes received a TPK 4.2 ± 3.9 days after admission, with a mean graft size of 8.9 ± 1.9 mm. Three eyes (7.5%) were enucleated. The corrected distance visual acuity of the entire study population increased from 2.0 ± 1.2 LogMAR to 0.96 ± 1.17 LogMAR.

Conclusion

In vivo confocal microscopy is a powerful tool for the early detection of fungal organisms in infectious keratitis. An early TPK with a large graft helps to eradicate the infection timely and results in a favorable visual acuity outcome and lower enucleation rate, especially when treating filamentous fungi.

Therapeutic and tectonic keratoplasty with simple cryopreserved remnants of donor corneas: an 11 year retrospective case series

This study sought to describe the use of deep-frozen donor corneal remnants preserved after keratoplasty procedures for therapeutic or tectonic keratoplasty without subsequent optical keratoplasty. This single-center retrospective consecutive case series analyzed the electronic medical records of patients who had undergone therapeutic or tectonic keratoplasty using deep-frozen donor remains preserved in Optisol-GS, for the past 11 years at Keimyung University Dongsan Medical Center. Fifty-five surgical cases in 46 patients were included. Twenty-three surgical cases in 18 patients underwent therapeutic keratoplasty for refractory infectious corneal ulcer. Complete eradication of primary infection was achieved in 14 patients (77.8%). Tectonic keratoplasty were performed 32 cases in 28 patients. Twenty-seven of 28 patients were ultimately able to maintain anatomical integrity (96.4%). Mean uncorrected visual acuity improved from 1.77 ± 0.94 preoperatively to 1.31 ± 0.95 at the last follow-up postoperatively in the tectonic graft group by logarithm of the minimal angle of resolution (P = 0.002). There were no cases of graft rejection. Keratoplasty using cryopreserved donor tissue is a suitable surgical alternative for infectious or non-infectious corneal ulcers in elderly patients or patients with poor general condition. It could be a viable alternative to overcome the shortage of corneal donors.

Indications and Surgical Techniques for Repeat Corneal Transplantation in Eastern China: A Twelve-Year Study

Purpose

To analyze the indications and surgical procedures for repeat keratoplasty in eastern China from 2008 to 2019.

Methods

This retrospective descriptive study included 418 eyes of 411 patients who underwent no less than 2 keratoplasties at the Eye, Ear, Nose and Throat Hospital of Fudan University from 2008 to 2019. Medical charts were reviewed. The primary indications for repeat keratoplasty, the reasons for regrafting, and the surgical techniques used in the treatment were collected and analyzed.

Results

Among 418 eyes, 337 eyes (80.6%) had one repeat keratoplasty, and 81 eyes (19.4%) had multiple repeat keratoplasties (≥2 repeat keratoplasties). The median interval between the initial keratoplasty and the first repeat keratoplasty was 25 months, and that between two keratoplasties after the first repeat keratoplasty was 27.5 months. Infectious keratitis was the leading primary indication for single repeat keratoplasty (80 cases, 23.7%) and multiple repeat keratoplasties (19 cases, 23.5%). The second most common primary indication was bullous keratopathy for single repeat keratoplasty (49 eyes, 14.5%) and chemical injury for multiple repeat keratoplasties (14 eyes, 17.3%). The main reason for regrafting was allograft rejection (262 cases, 49.3%), followed by endothelial dysfunction (92 cases, 17.3%), and for vision improvement after tectonic keratoplasty (60 cases, 11.3%). Penetrating keratoplasty (PKP) was the major technique used in repeat keratoplasty (447 cases, 84.2%). However, Descemet stripping endothelial keratoplasty was more frequently used than PKP (72.4% vs. 27.6%, P < 0.001) in the treatment of failed endothelial keratoplasty.

Conclusion

Infectious keratitis was still the leading cause of repeat keratoplasty in eastern China. Although PKP remains the major technique of repeat keratoplasty, the application of customized lamellar keratoplasty has greatly expanded in the last decade. Cautious selection of indications, surgical techniques, and timing for surgery is crucial for a good prognosis after repeat keratoplasty.

Comparison of complications and visual outcomes between big-bubble deep anterior lamellar keratoplasty and penetrating keratoplasty for fungal keratitis

BACKGROUND

To compare the postoperative complications and visual outcomes of big-bubble deep anterior lamellar keratoplasty (BB-DALK) and penetrating keratoplasty (PK) for fungal keratitis (FK).

METHODS

This retrospective study included 94 cases of BB-DALK for FK and 161 cases of PK for FK from a tertiary ophthalmology care centre.

RESULTS

The most common FK pathogens were Fusarium (n = 84, 32.9%) and Aspergillus (n = 67, 26.3%). The recurrence rates after BB-DALK and PK were 3.2 and 5%, respectively (p = 0.723). The follow-up duration was 31.9 ± 15.8 months in the BB-DALK group and 33.9 ± 15.0 months in the PK group. The immune rejection rate was significantly lower in the BB-DALK group than in the PK group (1.1 vs. 18.6%, p < 0.001), as was the incidence of secondary glaucoma (p = 0.018). Endothelial cell density in the BB-DALK group tended to be stable at postoperative month 6, whereas the PK group still attenuated at a hyper-physiological rate. Postoperative best-corrected visual acuity (BCVA) significantly improved in both groups (p < 0.001). No significant difference between-group was observed in BCVA, refractive cylinder, and spherical equivalent postoperatively.

CONCLUSION

Big-bubble DALK is a useful and safe alternative to PK for medically uncontrolled FK.

Noninvasive Diagnosis of Viral Keratouveitis with Retro-corneal Endothelial Plaques: A Case Series

Purpose: The aim of this study was to evaluate the noninvasive diagnostic methods in managing the herpetic keratouveitis with retro-corneal endothelial plaques.Methods: 12 patients suspected to have unilateral herpetic keratouveitis with retro-corneal endothelial plaques were included. Slit lamp photos, AS-OCT, IVCM and corneal scraping culture were taken in all cases to help diagnosing and managing the disease. All patients received systemic and topical anti-viral treatment immediately and combined with topical steroids three days later.Results: Corneal scraping culture ruled out bacterial and fungal infection. AS-OCT showed that the boundaries between the corneal endothelial surface were clear in all patients. Corneal endothelial density and subbasal nerve plexus significantly decreased in all patients. Endothelial plaques reduced or disappeared in all patients with the treatment.Conclusions: Retro-corneal endothelial plaques and hypopyon are associated clinical manifestations of viral keratouveitis. AS-OCT and IVCM enhanced early detection and assessment during the follow-ups of the disease.

The role of fungi in fungal keratitis

Fungal keratitis (FK) accounts for approximately half of the microbial keratitis encountered in low middle income countries (LMICs) and predominantly affect the working rural-poor. FK causes significant morbidity with the majority of patients left with moderate or worse visual impairment and approximately 25% requiring expensive and often unsuccessful surgical interventions. The severity of FK and the resultant corneal damage or resolution can be attributed to i) the virulence and bioburden of the fungal pathogen, ii) the host defense mechanism and immune response and iii) sub-optimal diagnostics and anti-fungal treatment strategies. This review provides a comprehensive overview of the multifaceted components that drive FK progression and resolution, highlighting where knowledge gaps exist and areas that warrant further research.

Recurrence of Infection in Corneal Grafts After Therapeutic Penetrating Keratoplasty for Microbial Keratitis

PURPOSE

To determine the factors responsible for the recurrence of infection after therapeutic penetrating keratoplasty (TPK) in severe microbial keratitis.

METHODS

This is a retrospective interventional case series that reviewed the medical records of 229 consecutive patients (2005-2017) who underwent TPK for microbial keratitis at a tertiary eye care center in Central India. The primary outcome was recurrence of the primary infection. The factors responsible for recurrence were identified by univariate and multivariate regression analysis.

RESULTS

The overall outcomes were clear graft in 50 (21.8%) eyes, failed graft in 139 (60.7%) eyes, evisceration in 19 (8.3%) eyes, phthisis bulbi in 14 (6.1%) eyes, repeat TPK in 2 (0.9%) eyes, and anterior staphyloma in 1 (0.4%) eye. Recurrence occurred in 63 (27.5%) eyes within 16.2 ± 13.8 (range: 2-66) days. Univariate analysis identified fungal etiology (P = 0.001), ulcer size > 60 mm (P = 0.001), limbal involvement (P = 0.001), endothelial exudates (P = 0.024), retro-iris exudates (P = 0.001), corneal perforation (P = 0.005), coexisting endophthalmitis (P < 0.001), and graft size ≥ 10 mm (P < 0.001) as significant risk factors. Multiple logistic regression identified fungal etiology (P = 0.013), retro-iris exudates (P = 0.011), coexisting endophthalmitis (P = 0.004), and graft size ≥ 10 mm (P = 0.058) as independent risk factors for recurrence. Presenting visual acuity of 20/200 or better was seen in 49 (21.4%) and 39 (17%) eyes, and no light perception in 11 (4.8%) and 26 (11.4%) eyes at postoperative months 1 and 3, respectively.

CONCLUSIONS

Fungal etiology, retro-iris exudates, coexisting endophthalmitis, and larger grafts were susceptible to recurrence. Early surgery may mitigate most of these factors. Despite the risk of recurrence, TPK remains an effective treatment in severe nonresponsive keratitis.

Endothelial Plaques as Sign of Hyphae Infiltration of Descemet's Membrane in Fungal Keratitis

Background

To evaluate the relationship between corneal endothelial plaques and fungal hyphae infiltration in fungal keratitis.

Methods

Retrospective cross-sectional study of 60 fungal keratitis patients who underwent keratoplasty between January 2013 and March 2017. The endothelial plaques were graded as follows: grade 1, 1–3 endothelial plaques; grade 2, 4–8 endothelial plaques; and grade 3, more than 8 endothelial plaques or dense, merging endothelial plaques. The fungal pathogen culture and histopathology of diseased Descemet's membrane were evaluated.

Results

According to endothelial plaque grading, 3 patients were grade 1, 29 patients were grade 2, and 28 patients were grade 3. The PK surgery was performed in 57 patients with endothelial plaques of grade 2 and grade 3 and DALK surgery in 3 patients of grade 1. The predominating fungal pathogens were Aspergillus species (63.2%). All 57 patients with grade 2 and grade 3 had fungal hyphae in Descemet's membrane based on calcofluor white staining or PAS staining. In patients with grade 3, more hyphae and inflammatory cells were found in Descemet's membrane. The immunohistochemical staining of endothelial plaques revealed that CD15 and CD68 were positive in most cells. During the follow-up, 2 out of 3 patients who underwent DALK had recurrent fungal keratitis.

Conclusions

Endothelial plaques are considered as a sign of hyphae infiltrating Descemet's membrane. PK should be performed once plaques are detected in endothelium during the surgery.

Incidence and Outcomes of Positive Donor Rim Cultures and Infections in the Cornea Preservation Time Study

PURPOSE

To assess donor rim culture results and outcomes of ocular infections in the Cornea Preservation Time Study (CPTS).

METHODS

Donor corneal rim cultures were optional. Donor characteristics were assessed for association with positive cultures using the Fisher exact test and Poisson regression analyses. Incidence rates of ocular infections were estimated, and 95% confidence intervals were calculated.

RESULTS

Cultures were performed in 784 (58.9%) of the 1330 cases. For the 0 to 7-day versus 8 to 14-day preservation time groups, respectively, positive fungal growth occurred in 10 of 397 (2.5%) versus 5 of 387 (1.3%) corneas (P = 0.30), whereas positive bacterial cultures occurred in 6 of 397 (1.5%) versus 4 of 387 (1.0%) corneas (P = 0.75). Surgeon-prepared tissue remained a significant risk for positive fungal cultures [relative risk (RR) of surgeon- versus eye-bank-prepared, 2.85; 95% CI (1.02-7.98)], whereas younger donors [RR per year of age, 0.96; 95% CI (0.93-1.00)] and accidental death donors [RR of accident versus disease, 3.71; 95% CI (1.36-10.13)] were at a greater risk for positive bacterial cultures. Fungal infection (Candida glabrata) developed in 1 (6.7%) of 15 recipients with a positive fungal culture, and no recipient infections occurred with positive bacterial culture. With one additional fungal keratitis (Candida albicans) and one bacterial endophthalmitis (E. coli) with no rim culture performed, a total of 2 of 1330 eyes (0.15%) developed fungal and 1/1330 eyes (0.08%) developed bacterial postkeratoplasty infections.

CONCLUSIONS

A longer preservation time was not associated with a higher rate of positive donor rim cultures. The overall rate of infection across the entire cohort was low.

Observation of Retrocorneal Plaques in Patients With Infectious Keratitis Using Anterior Segment Optical Coherence Tomography

PURPOSE

Endothelial plaques are a typical characteristic in patients with fungal keratitis. However, bacterial keratitis and herpetic keratouveitis are rarely associated with fibrin formation on the retrocorneal surface. This study was conducted to examine plaques attached to the endothelium in patients with infectious keratitis using anterior segment optical coherence tomography (AS-OCT).

METHODS

Seventeen patients (10 women and 7 men; mean age, 75 ± 15.5 years) suspected to have infectious keratitis with retrocorneal plaques were included. AS-OCT was used to acquire a scan of the retrocorneal plaque at the patient's first visit.

RESULTS

Based on the culture results and detection of viral DNA, the patients were diagnosed with fungal keratitis (6 patients), bacterial keratitis (8 patients), and herpetic keratouveitis (3 patients). Examination of the cornea using AS-OCT showed a clear boundary between the corneal endothelial surface and plaque in 8 patients with bacterial keratitis and in all patients with herpetic keratitis. Moreover, a space between the corneal endothelial surface and plaque was found in 3 patients with bacterial keratitis. In 5 patients with fungal keratitis, the AS-OCT images showed an unclear boundary between the corneal endothelial surface and plaque, and high reflection of the plaque was extended from the corneal lesion.

CONCLUSIONS

Endothelial plaques in patients with fungal keratitis could continue from the corneal lesion. Observation of retrocorneal plaques using AS-OCT could be used in the diagnosis of infectious keratitis.

Excisional keratectomy combined with focal cryotherapy and amniotic membrane inlay for recalcitrant filamentary fungal keratitis: A retrospective comparative clinical data analysis

The aim of the present study was to investigate the efficacy of a novel surgical intervention, excisional keratectomy combined with focal cryotherapy and amniotic membrane inlay (EKCAI), for the treatment of recalcitrant filamentary fungal keratitis. A retrospective analysis was performed of patients who underwent excisional keratectomy combined with conjunctival flap inlay (EKCFI), EKCAI or therapeutic penetrating keratoplasty (TPK) from January 2006 to January 2011. Recalcitrance was determined as being unresponsive to standard medical antifungal therapy for at ≥1 week. Outcome measures among the three intervention modalities were compared. A total of 128 patients had a follow-up of ≥1 year after the primary intervention. The success rates of interventions at 1-year follow-up were 58.33% in the EKCFI group, 88.37% in the EKCAI group and 93.44% in the TPK group (P<0.0002). The preoperative visual acuity of the three groups were similar (P=0.6458), while the postoperative best-corrected visual acuity (BCVA) of patients without recurrence was significantly different among the three groups 3 months after surgery. The best postoperative BCVA was found in the TPK group, while the worst was in the EKCFI group. In conclusion, EKCAI does not require donor cornea, is straightforward surgically, and has a favorable success rate compared with EKCFI.

Fungal keratitis in patients with corneal ulcer attending Minilik II Memorial Hospital, Addis Ababa, Ethiopia

BACKGROUND

Fungal keratitis is an important cause of corneal blindness all over the world. Although there are several reports on fungal keratitis from developing and developed countries, fungal keratitis in Ethiopia is poorly known. The aim of this study was to determine the prevalence of fungal keratitis and spectrum of fungi implicated in causing the infection.

METHODS

The present study was a single institutional cross-sectional study carried out in Minilik II Memorial Hospital eye clinic, Addis Ababa, Ethiopia from September 2014 to August 2015. Corneal scraping was obtained under aseptic condition with sterile 21 gauge needle by an ophthalmologist from patients suspected of microbial keratitis. Each scraping was inoculated onto Sabouraud Dextrose Agar in C-shaped streaks and incubated at 25 °C aerobically for four weeks. Cultures of mycelia fungi were identified by examining macroscopic and microscopic characteristics of their colonies. Yeasts were identified by employing biochemical and assimilation test procedures and using CHROMagar Candida culture. All data were coded, double entered and analyzed using SPSS version 20.

RESULT

Out of 153 cases of microbial keratitis, fungi were recovered from 69 patients giving fungal keratitis prevalence of 45.1. Patients from rural areas were significantly affected than patients in urban regions (P = 0.005). Age groups of 25-34 (P = 0.017) and 15-24 years (P = 0.008) were significantly affected. Fungal keratitis was significantly associated with farmers (P = 0.0001), daily laborers (P = 0.0001), unemployed (P = 0001) and students (P = 0.004). Fungal keratitis was statistically associated with trauma (P = 0.006), and diabetes (P = 0.024). Seventy six fungal isolates were recovered, of which molds accounted 63 (82.9 %) of the total isolates. Fusarium and Aspergillus species were the two predominant molds accounting 27.6 and 25 % of the total isolates respectively. Yeast isolates accounted only 17.1 %.

CONCLUSION

High prevalence of fungal keratitis recorded in the present study, highlights the need for nationwide study on fungal keratitis and precise identification of the causative fungi and institution of appropriate treatment strategy.

Surgical management of fungal endophthalmitis resulting from fungal keratitis

AIM

To report the fungal organisms, clinical features, surgical treatment strategies, and outcomes of patients with culture-proven exogenous fungal endophthalmitis (EFE) secondary to keratitis, and evaluate the role of surgery in the treatment.

METHODS

The clinical records of 27 patients (27 eyes) with culture-proven EFE resulting from fungal keratitis treated at Shandong Eye Institute from January 2007 to January 2015 were retrospectively reviewed. Information about fungal culture results, clinical features, surgical procedures, and final visual acuity was obtained.

RESULTS

There were 39 positive culture results from samples of cornea, hypopyon, vitreous and lens capsule, accounting for 56%, 26%, 15% and 2.5%, respectively. Fusarium was identified in 44% (12/27) of the eyes, followed by Aspergillus in 22% (6/27). Posterior segment infection was involved in 78% (21/27) of the patients. The corneal infection was larger than 3 mm ×3 mm in 89% (24/27) of the patients, and 22% (6/27) of them had the entire cornea, and even the sclera involved. Three eyes had silicone oil tamponade, and two eyes had retinal detachment. Twenty-two eyes (81.5%) underwent penetrating keratoplasty (PKP), and over half of them (54.5%) were operated within 3d from the onset of antifungal therapy. Fourteen eyes (52%) underwent intracameral antifungal drug injection, and three of them required repeated injections. Fifteen eyes (55.6%) underwent pars plana vitrectomy (PPV). The rate of the eyes undergoing PPV as the initial surgical procedure was 60% (9/15), lower than 77% in PKP. Intravitreal injection was given in 59% of the eyes (16/27), and 75% of them required repeated injections. The final visual acuity was 20/100 or better in 37% of the eyes, and better than counting fingers in 55.6% of the eyes. Five eyes (18.5%) were eviscerated. In the two eyes with concurrent retinal detachment, one achieved retinal reattachment, and the other was eviscerated. In the three eyes with silicone oil tamponade, two eyes received silicone oil removal, and the other one was eviscerated.

CONCLUSION

Fusarium and Aspergillus are the dominant pathogens in EFE resulting from keratitis. Aggressive antifungal surgeries including multiple intravitreal injections, PKP and core vitrectomy (especially in the initial surgery) are helpful procedures to improve prognosis of severe EFE secondary to keratitis.

Big bubble deep anterior lamellar keratoplasty for management of deep fungal keratitis

Objective. To evaluate the therapeutic effect of big bubble deep anterior lamellar keratoplasty (DALK) in patients with deep fungal keratitis. Methods.Consecutive patients who had DALK for deep fungal keratitis at Shandong Eye Hospital between July 2011 and December 2012 were included. In all patients, the infiltration depth was more than 4/5ths of the corneal thickness. DALK surgery was performed with bare Descemet membrane (DM) using the big bubble technique. Corrected distance visual acuity (CDVA), graft status, and intraoperative and postoperative complications were monitored. Results. Big bubble DALK was performed in 23 patients (23 eyes). Intraoperative perforation of the DM occurred in two eyes (8.7%) during stromal dissection. The patients received lamellar keratoplasty with an air bubble injected into the anterior chamber. Double anterior chamber formed in 3 eyes (13.0%). Mean CDVA of the patients without cataract, amblyopia, and fungal recurrence was improved from preoperative HM/20 cm−1.0 (LogMAR) to 0.23 ± 0.13 (LogMAR) at the last followup (P < 0.01). Fungal recurrence was found in two patients (8.7%). Corneal stromal graft rejection was noted in one patient (4.3%). Conclusions. DALK using the big bubble technique seems to be effective and safe in the treatment of deep fungal keratitis unresponsive to medication.

Excimer laser phototherapeutic keratectomy for the treatment of clinically presumed fungal keratitis

This retrospective study was to evaluate treatment outcomes of excimer laser phototherapeutic keratectomy (PTK) for clinically presumed fungal keratitis. Forty-seven eyes of 47 consecutive patients underwent manual superficial debridement and PTK. All corneal lesions were located in the anterior stroma and were resistant to medication therapy for at least one week. Data were collected by a retrospective chart review with at least six months of follow-up data available. After PTK, infected corneal lesions were completely removed and the clinical symptoms resolved in 41 cases (87.2%). The mean ablation depth was 114.39 ± 45.51 μm and diameter of ablation was 4.06 ± 1.07 mm. The mean time for healing of the epithelial defect was 8.8 ± 5.6 days. Thirty-four eyes (82.9%) showed an improvement in best spectacle-corrected visual acuity of two or more lines. PTK complications included mild to moderate corneal haze, hyperopic shift, irregular astigmatism, and thinning cornea. Six eyes (12.8%) still showed progressed infection, and conjunctival flap covering, amniotic membrane transplantation, or penetrating keratoplasty were given. PTK is a valuable therapeutic alternative for superficial infectious keratitis. It can effectively eradicate lesions, hasten reepithelialization, and restore and preserve useful visual function. However, the selection of surgery candidates should be conducted carefully.

Corneal blindness and xenotransplantation

Approximately 39 million people are blind worldwide, with an estimated 285 million visually impaired. The developing world shoulders 90% of the world's blindness, with 80% of causative diseases being preventable or treatable. Blindness has a major detrimental impact on the patient, community, and healthcare spending. Corneal diseases are significant causes of blindness, affecting at least 4 million people worldwide. The prevalence of corneal disease varies between parts of the world. Trachoma, for instance, is the second leading cause of blindness in Africa, after cataracts, but is rarely found today in developed nations. When preventive strategies have failed, corneal transplantation is the most effective treatment for advanced corneal disease. The major surgical techniques for corneal transplantation include penetrating keratoplasty (PK), anterior lamellar keratoplasty, and endothelial keratoplasty (EK). Indications for corneal transplantation vary between countries, with Fuchs' dystrophy being the leading indication in the USA and keratoconus in Australia. With the exception of the USA, where EK will soon overtake PK as the most common surgical procedure, PK is the overwhelming procedure of choice. Success using corneal grafts in developing nations, such as Nepal, demonstrates the feasibility of corneal transplantation on a global scale. The number of suitable corneas from deceased human donors that becomes available will never be sufficient, and so research into various alternatives, for example stem cells, amniotic membrane transplantation, synthetic and biosynthetic corneas, and xenotransplantation, is progressing. While each of these has potential, we suggest that xenotransplantation holds the greatest potential for a corneal replacement. With the increasing availability of genetically engineered pigs, pig corneas may alleviate the global shortage of corneas in the near future.

Fusarium keratitis: genotyping, in vitro susceptibility and clinical outcomes

PURPOSE

To determine differences in the clinical characteristics and antifungal susceptibility patterns among molecularly characterized ocular Fusarium sp isolates.

METHODS

Fifty-eight isolates of Fusarium sp obtained from 52 eyes of 52 patients were retrieved from the Ocular Microbiology Laboratory of the Bascom Palmer Eye Institute and grown in pure culture. These isolates were characterized based on DNA sequence analysis of the ITS1/2 and ribosomal deoxyribonucleic acid regions. Antifungal susceptibilities were determined for each isolate using broth microdilution methods, and the corresponding medical records were reviewed to determine the clinical outcomes.

RESULTS

Fusarium solani isolates had significantly higher values of minimum inhibitory concentration for 90% isolates (MIC90) with voriconazole than F. non-solani organisms (16 and 4 μg/mL, respectively). Isolates of F. solani also exhibited a significantly longer time to cure (65 vs. 40.5 days), a worse follow-up best-corrected visual acuity (20/118 vs. 20/36), and an increased need for urgent surgical management (7 vs. 0 penetrating keratoplasties) when compared with those of F. non-solani.

CONCLUSIONS

This is the first report to examine the correlation between ocular genotyped Fusarium sp and clinical outcomes. It supports the overall worse prognosis of F. solani versus F. non-solani isolates, including higher voriconazole resistance by the former. The clinical implementation of molecular-based diagnostics and antifungal efficacy testing may yield important prognostic and therapeutic information that could improve the management of fungal ocular infections.

A case of interface keratitis following anterior lamellar keratoplasty

Anterior lamellar keratoplasty (ALK) is indicated in patients with anterior corneal opacities. Benefits over penetrating keratoplasty include quicker visual rehabilitation, less postoperative astigmatism, and preservation of the host endothelium, thus minimizing the chances of graft rejection. A rare complication of lamellar corneal surgery is infectious interface keratitis between the donor and host tissue. We report a case of infectious interface keratitis following automated ALK successfully treated medically and by removal of the ALK disk, eventually having a deep anterior lamellar keratoplasty with good visual recovery.

Therapeutic keratoplasty for microbial keratitis

PURPOSE OF REVIEW

The purpose of this review is to provide an update of peer-reviewed literature published over the previous 2 years on various aspects of therapeutic keratoplasty.

RECENT FINDINGS

Therapeutic keratoplasty has a definitive role in the management of progressive microbial keratitis refractory to medical therapy. The primary aim of the procedure is to eliminate the infectious disease process and establish the integrity of the globe. This procedure offers a microbiological cure rate of up to 100% in bacterial keratitis; recurrence of infection remains a concern following fungal infections and Acanthamoeba keratitis. Newer techniques like corneal debulking allow maximal preservation of the iris tissue in cases of perforated corneal ulcers. Lamellar procedures are emerging as promising alternatives to the full thickness graft in cases of infectious keratitis sparing the Descemet's membrane. In addition to adept intraoperative skills, intensive postoperative treatment and meticulous follow-up are pivotal to ensure success of a therapeutic graft.

SUMMARY

Therapeutic keratoplasty is a challenging procedure and is associated with a poor prognosis for graft survival as compared with the optical grafts. The recent advances in lamellar keratoplasty and antimicrobial therapy contribute to the success in terms of microbiological cure and improved visual outcomes.

Anterior lamellar keratoplasty over penetrating keratoplasty for optical, therapeutic, and tectonic indications: a case series

PURPOSE

To report a consecutive case series of patients who underwent anterior lamellar keratoplasty (ALK) over a preexisting penetrating keratoplasty (PK).

DESIGN

Retrospective, interventional case series.

METHODS

Eight patients (8 eyes) were identified from the Singapore Corneal Transplant Study database, in a single institution (Singapore National Eye Center) from patients who underwent ALK performed over a PK. Main outcome measures were final visual acuity (VA), graft failure (ALK, PK or both), successful restoration of tectonic integrity in tectonic indications, and eradication of infection in therapeutic cases.

RESULTS

The indications for surgery were therapeutic in 3 patients, optical in 3 patients, and tectonic in 2 patients. Postoperatively the best-corrected visual acuity (BCVA) improved in 5 eyes and remained unchanged in 3 eyes. Mean VA improved significantly after ALK; the mean preoperative BCVA was 1.52 +/- 0.25 and the mean postoperative BCVA was 0.87 +/- 0.26 (P = .032). Three of the 8 eyes post-lamellar keratoplasty (LK) managed to attain a BCVA equal to post-PK BCVA. Two patients had suture micro-perforations while 1 patient required a repeat ALK for recurrence of infection.

CONCLUSION

ALK may be a considered as a viable alternative to a repeat PK for a variety of optical, therapeutic, and tectonic indications.