Comparison of therapeutic effects between big-bubble deep anterior lamellar keratoplasty and penetrating keratoplasty for medically unresponsive Acanthamoeba keratitis.

PURPOSE: To compare the outcomes of big-bubble deep anterior lamellar keratoplasty (BB-DALK) and penetrating keratoplasty (PKP) in the management of medically unresponsive Acanthamoeba keratitis (AK). METHODS: This retrospective study included 27 eyes of BB-DALK and 24 eyes of PKP from a tertiary ophthalmology care centre. Glucocorticoid eye drops were subsequently added to the treatment plan 2 months postoperatively based on the evaluation using confocal laser scanning microscopy. The clinical presentations, best-corrected visual acuity (BCVA), postoperative refractive outcomes, graft survival, and Acanthamoeba recurrence were analyzed. RESULTS: The AK patients included in the study were in stage 2 or stage 3, and the percentage of patients in stage 3 was higher in the PKP group (P = 0.003). Clinical presentations were mainly corneal ulcers and ring infiltrates, and endothelial plaques, hypopyon, uveitis and glaucoma were more common in the PKP group (P = 0.007). The BCVA and the graft survival rate showed no statistically significant differences between the two groups at 1 year after surgery. However, 3 years postoperatively, the BCVA of 0.71 ± 0.64 logMAR, the graft survival rate of 89.5%, and the endothelial cell density of 1899 ± 125 cells per square millimeter in the BB-DALK group were significantly better than those of the PKP group (P = 0.010, 0.046, and 0.032, respectively). 3 eyes (11.1%) in the BB-DALK group and 2 eyes (8.3%) in the PKP group experienced Acanthamoeba recurrence, but the rates showed no statistically significant difference between the two groups (P = 1.000). In the PKP group, immune rejection and elevated intraocular pressure were observed in 5 and 6 eyes, respectively. CONCLUSION: Corneal transplantation is recommended for AK patients unresponsive to antiamoebic agents. The visual acuity and graft survival can be maintained after BB-DALK surgery. Acanthamoeba recurrence is not related to the surgical approach performed, whereas complete dissection of the infected corneal stroma and delayed prescribing of glucocorticoid eye drops were important to prevent recurrence.

Use of In Vivo Corneal Confocal Microscopy to Guide Excimer Laser With Adjunctive Mitomycin C for Treatment of Recalcitrant Acanthamoeba Keratitis.

PURPOSE: The aim of this study was to describe 3 cases of recalcitrant Acanthamoeba keratitis (AK) that were successfully treated using in vivo corneal confocal microscopy (IVCM) to guide excimer laser ablation depth with adjunctive mitomycin C 0.02%. METHODS: Three patients diagnosed with AK did not respond to several weeks of intensive topical therapy with antiamoebic agents. The patient underwent phototherapeutic keratectomy with topical mitomycin C 0.02% application. The maximum stromal depth of cysts measured by IVCM was 80 µm, 100 µm, and 240 µm, and the stromal ablation depths were 80 µm, 100 µm, and 100 µm, respectively. RESULTS: In all 3 eyes, AK resolved after a single excimer laser application, and topical treatment was gradually discontinued within 6 weeks afterward. In 1 eye, penetrating corneal transplantation was performed 6 weeks after phototherapeutic keratectomy because of ongoing severe corneal pain. IVCM and histology of the corneal transplant did not reveal any Acanthamoeba cysts within the excised corneal button. No recurrence was observed during the follow-up period of 19 to 34 months. CONCLUSIONS: IVCM-guided phototherapeutic keratectomy with mitomycin C 0.02% seems to be a safe and successful approach for the treatment of AK, especially in cases of resistance to topical treatment. Corneal IVCM should be performed before laser application to measure cyst depth, determine ablation depth, and assess postoperative treatment success.

Novel Map Biopsy Technique to Define the Extent of Infection Before Penetrating Keratoplasty for Acanthamoeba Keratitis.

PURPOSE: The purpose of this study was to report a novel approach of prepenetrating keratoplasty (PKP) corneal map biopsies to define the extent of Acanthamoeba cyst infiltration in recalcitrant Acanthamoeba keratitis. METHODS: Corneal map biopsies were performed 1 week before PKP. Four biopsies, 1 from each peripheral corneal quadrant, were obtained to delineate the extent of microscopic infection. Histological results of these map biopsies were used to determine the size and location of the subsequent PKP. RESULTS: In our first case, map biopsies revealed Acanthamoeba cysts in 2 of the 4 biopsies. This led to an inferotemporally eccentric 8.5-mm PKP. The final histology report indicated that the closest resection margin was 0.08 mm. In our second case, the peripheral map biopsies were clear and an inferiorly eccentric 8.25-mm PKP was performed. The final histology report indicated that the closest resection margin was 2.3 mm. Both grafts have remained clear at 6 months postoperatively. CONCLUSIONS: Map biopsies of the cornea can achieve total removal of the corneal tissues infested with Acanthamoeba cysts and prevent reinfection of the donor graft.

Corneal Transplantation for Infectious Keratitis: A Prospective Dutch Registry Study.

PURPOSE: The aim of this study was to analyze real-world practice patterns and graft survival after corneal transplantation for infectious keratitis in the Netherlands. METHODS: All consecutive keratoplasties for infectious keratitis registered in the Netherlands Organ Transplant Registry were included. Graft survival was analyzed using Kaplan-Meier survival curves with Cox regression to compare the 3 most common pathogens with subgroup analysis for type and reason of transplantation, sex, and graft size. Multivariable analysis was performed using the same explanatory factors. RESULTS: Between 2007 and 2017, 1111 keratoplasties for infectious keratitis were registered in the Netherlands Organ Transplant Registry. The most common pathogens were viruses (n = 437), bacteria (n = 271), and Acanthamoeba (n = 121). Human leukocyte antigen (HLA) matching did not provide a significant survival benefit, whereas emergency procedures showed worse graft survival [hazard ratio (HR) = 0.40, P = 0.120; HR = 2.73, P < 0.001, respectively]. Graft size >8.5 mm was significantly worse than graft size 8.5 mm (HR = 2.062, P = 0.010). In therapeutic keratoplasty, graft survival was significantly worse for Acanthamoeba than viral keratitis (HR = 2.36, P = 0.008). In the multivariable model, adjusting for graft size, type, and reason for transplantation, viral and bacterial keratitis did not differ significantly in graft survival, and Acanthamoeba showed a significantly worse prognosis (vs. viral keratitis, HR = 2.30, P < 0.001; bacterial keratitis, HR = 2.65, P < 0.001). CONCLUSIONS: Viral keratitis was the most common indication for transplantation, followed by bacterial and Acanthamoeba keratitis. HLA matching did not offer protection over elective non-HLA-matched procedures, whereas emergency procedures and grafts sized >8.5 mm showed poor survival. In optical keratoplasty, survival is high for all pathogens, whereas in therapeutic keratoplasty Acanthamoeba shows poor outcome.

Therapeutic keratoplasty for severe Acanthamoeba keratitis: risk factors, clinical features, and outcomes of postoperative recurrence.

PURPOSE: To investigate the effect of therapeutic keratoplasty (TKP) in patients with severe Acanthamoeba keratitis (AK) and to analyse the clinical features and risk factors for recurrence. METHODS: Clinical data of patients with severe AK treated with lamellar keratoplasty (LK) or penetrating keratoplasty (PK) due to ineffective drug therapy were analysed in this retrospective study. The effects of keratoplasty, clinical features, and risk factors for recurrence were analysed. RESULTS: The cohort comprised of 58 patients (59 eyes). Of these, 36 eyes were treated with PK and 23 were treated with LK. The probabilities of successful globe salvage were 91.7% and 91.3%, respectively. The final visual acuity (VA) was ≥ 20/60 in 14 eyes (38.9%) that underwent PK and 15 eyes (65.2%) that underwent LK. Postoperative recurrence of Acanthamoeba infection was detected in 10 eyes; 6 eyes (16.7%) showed recurrence after PK, and 4 eyes (17.4%) showed recurrence after LK. Recurrence occurred between 3 and 80 days (median, 14.5 days) after the operation. The risk factors for recurrence after LK were topical corticosteroid use before diagnosis (p = 0.040) and hypopyon (p = 0.009), while those after PK were topical corticosteroid use before diagnosis (p = 0.045). Clinical manifestations of postoperative recurrence include greyish-white infiltration of the recipient bed, anterior chamber inflammation, graft oedema, and keratic precipitate. CONCLUSION: TKP is a treatment option for severe AK that responds poorly to antiamoebic therapy (AAT), although Acanthamoeba infection may relapse, and the visual prognosis is guarded. Topical corticosteroid use before AAT and hypopyon is the two risk factors for recurrence.

Therapeutic Corneal Transplantation in Acanthamoeba Keratitis: Penetrating Versus Lamellar Keratoplasty.

PURPOSE: The purpose of this article was to compare clinical outcomes between therapeutic penetrating keratoplasty (TPK), therapeutic deep anterior lamellar keratoplasty (TDALK), and optical penetrating keratoplasty (OPK) in Acanthamoeba keratitis. METHODS: A literature search was conducted in online libraries from 1980 to 2021. The primary end points were best-corrected visual acuity (VA), graft survival, and infection recurrence. In addition, we enrolled 35 consecutive patients with AK from our practice evaluating best-corrected VA and high-order aberrations. RESULTS: A total of 359 AK eyes from 33 published studies were retrieved from 175 publications screened. One hundred sixty-five eyes (73%) that underwent TPK and 39 eyes (84%) treated with TDALK had a clear graft at the last follow-up visit. Only the patients treated with OPK had 82 clear grafts (94%) during the follow-up period. Forty-seven (21%) of TPK patients reached VA ≥20/30, compared with 11 (25%) of TDALK patients and 35 (40%) of OPK patients. Acanthamoeba infection recurrence occurred in 38 eyes (16.8%) that underwent TPK, 9 (19%) that underwent TDALK, and 8 (9.5%) that underwent OPK. In our series, best-corrected visual acuity in nonsurgically treated patients was 1 ± 0.50 logMAR compared with 0 logMAR of surgically treated patients. High-order aberrations were significantly lower in surgically treated eyes after AK resolution, particularly in TDALK when compared with TPK patients. Best-corrected visual acuity was better in TDALK patients compared with TPK patients. CONCLUSIONS: After AK resolution by 6 to 12 months of medical treatment, OPK seems to be the best surgical choice in patients with AK. If AK could not be eradicated by medical therapy, TDALK may be chosen in the early disease stage and TPK in later stages.

Endothelial Cell Density and Central Corneal Thickness following Penetrating Keratoplasty of Acanthamoeba Keratitis Patients - A Retrospective Cross-Sectional Observational Study.

PURPOSE: To analyze endothelial cell density (ECD) and central corneal thickness (CCT) following penetrating keratoplasty (PKP) in Acanthamoeba keratitis (AK) patients. PATIENTS AND METHODS: In this retrospective, clinical, single-center, cross-sectional, observational study, patients were enrolled who underwent PKP at the Department of Ophthalmology of Saarland University Medical Center, Homburg/Saar, Germany between May 2008 and December 2016 with the diagnosis of AK. In all, 33 eyes of 33 patients (14 males, 42%) were enrolled; their mean age at the time of surgery was 39.5 ± 14.3 years. Postoperatively, AK patients received topical polyhexamethylene biguanide, propamidine isethionate, neomycin sulphate/gramicidin/polymixin B sulfate, and prednisolone acetate eye drops (5 ×/day each), and the topical treatment was tapered sequentially with 1 drop every 6 weeks over 6 months. CCT was recorded using Pentacam HR Scheimpflug tomography and ECD with the EM-3000 specular microscope before surgery and 3 and 6 months after surgery as well as after the first and second (complete) suture removal. RESULTS: ECD tended to decrease significantly from the time point before surgery (2232 ± 296 cells/mm2) to the time point 3 months after surgery (1914 ± 164 cells/mm2; p = 0.080) and to the time point after the first suture removal (1886 ± 557 cells/mm2; p = 0.066) and decrease significantly to the time point after the second suture removal (1650 ± 446 cells/mm2; p = 0.028). CCT did not change significantly over the analyzed time period (p ≥ 0.475). CONCLUSION: In AK, endothelial cell loss does not seem to be accelerated following PKP, despite the postoperative use of diamidine and biguanide. A subsequent prospective comparative study should confirm our retrospective longitudinal analysis.

Assessment of Antimicrobial Activity of Dehydrated Amniotic Membrane in Infectious Keratitis: A Small Retrospective Case Series and In Vitro Study.

PURPOSE: To describe a small case series of infectious keratitis with poor visual outcomes after amniotic membrane (AM) placement and to prospectively evaluate whether AM demonstrates antibacterial activity in vitro against pathogens commonly isolated from infectious corneal ulcers. METHODS: A retrospective case series and in vitro study of antibacterial activity of dehydrated AM using disk diffusion and measurement of inhibitory zones for bacterial assessment and inverted microscopy analysis for Acanthamoeba sp. growth. RESULTS: Three cases of known etiology infectious keratitis are described where the clinical presentation worsened after treatment with AM. In vitro analysis of dehydrated AM, with and without a soft contact lens, demonstrated no inhibition of growth against Pseudomonas aeruginosa or Streptococcus pneumoniae. There was minimal growth inhibition of Staphylococcus aureus, although these zones of inhibition were much smaller than that surrounding the positive control. For Acanthamoeba sp., solubilized, dehydrated AM did not alter cyst density. CONCLUSIONS: In an in vitro analysis, dehydrated AM did not provide evidence for a potentially clinically meaningful antibacterial effect against organisms commonly isolated from corneal ulcers.

Acanthamoeba Keratitis - A Case Report.

INTRODUCTION: Acanthamoeba keratitis is a serious infection of the cornea which causes severe inflammation of the eye and loss of vision. CASE DESCRIPTION: A 45 years female came with a history of trauma of right eye with vegetative matter with severe pain and redness. Patient was treated with antibacterial, antifungal eye drops but the condition deteriorated. Diagnosis was based on presence of motile trophozoites and cyst in the culture of non nutrient agar with a lawn of E coli of the corneal ulcer scraping. Therapeutic penetrating keratoplasty was performed as the patient's condition deteriorated. CONCLUSION: Acanthamoeba keratitis is a rare parasitic vision threatening infection with poor prognosis in comparison to other infectious keratitis. Therefore prevention is very important.

Case Report: Suspected Donor Transmission of Acanthamoeba Keratitis After Deep Anterior Lamellar Keratoplasty.

PURPOSE: In our report, we present a suspected case of donor-derived Acanthamoeba keratitis after deep anterior lamellar keratoplasty. To the authors' knowledge, there have been no confirmed cases of Acanthamoeba keratitis transmission through corneal transplantation. METHODS: Deep anterior lamellar keratoplasty was performed on the right eye of a 33-year-old man with severe bilateral keratoconus and an intolerance to all forms of contact lenses. The postoperative visual acuity deteriorated, while inflammation, rising ocular pressure, increasing corneal thickness, and severe eye pain began to present. Confocal imaging revealed hyperreflective cysts and trophozoite figures representative of amoebic keratitis. Despite an additional penetrating keratoplasty, antiamoeba therapy, and corneal crosslinking, the patient's condition worsened, resulting in stromal melt and corneal perforation. Emergent combined surgery of temporary keratoprosthesis, vitrectomy, lensectomy, and iridectomy was performed, along with Ahmed valve shunt placement and another penetrating keratoplasty. RESULTS: The infection was resistant to aggressive antiamoeba therapy, but after the emergent combined surgery, the graft re-epithelialized quickly and has since remained clear, with no presence of keratitis. CONCLUSIONS: Several signs led us to believe that this case was donor-derived. There was little opportunity for graft exposure to the amoeba, and deep amoebic cysts and trophozoites were present on postoperative week 1-a highly unusual time course and depth of invasion for primary amoebic infection. In addition, pathological analysis revealed cysts only within the confines of the donor tissue and none in the recipient; Acanthamoeba cysts would have been present in the recipient rim tissue if the infection originated from the patient himself.

Outcome of therapeutic deep anterior lamellar keratoplasty in advanced Acanthamoeba keratitis.

Purpose: To report and analyze the outcomes of therapeutic deep anterior lamellar keratoplasty (DALK) in patients with advanced Acanthamoeba keratitis (AK). Methods: Medical records of microbiologically confirmed AK, underwent DALK from 2004 to 2017, were reviewed and the data related to early and late outcome including complications were retrieved. Outcome of cases with largest diameter of infiltrate ≥8 mm at the time of surgery (advanced keratitis) were analyzed and compared with those with less severe keratitis (infiltrate size less than 8 mm). Results: Out of 23 patients of AK in whom DALK was performed, ten (43.4%) patients had advanced keratitis. Mean age of these patients was 38.7 ± 8.6 years (range, 25 to 56). Median visual acuity at presentation was 2.78 (IQR, 1.79-3.0) that improved to 1.79 (IQR, 0.70-2.78) postoperatively. Early complications included recurrence of AK in 2 (20%), Descemet's membrane detachment in 5 (50%), and persistent epithelial defect in 3 (30%) cases. Overall, 6 (60%) grafts failed, whereas 4 (40%) patients had clear graft at their last follow-up. Median follow-up of these cases was 5 months (IQR, 1.4-11.4). One graft developed stromal rejection, which resolved with increased dose of corticosteroids. In comparison, DALK performed for less severe keratitis (N = 13) had 1 (7.6%) recurrence and 2 (15.8%) grafts failure (OR, 8.25). The probability of one-year graft survival and eradication of infection was 32% and 74.1%, respectively, in advanced cases compared to 91.6% and 83.9% in less severe cases. Conclusion: Outcome of DALK in advanced Acanthamoeba keratitis is less favorable compared to those carried out for less severe keratitis cases.

Early therapeutic lamellar keratoplasty for acanthamoeba keratitis followed by implantable Collamer lens for visual rehabilitation.

We are reporting the case of a 25-year-old female who developed acanthamoeba keratitis after wearing contact lenses for high myopia. She was diagnosed as acanthamoeba and started the treatment of antiacanthamoeba for 3 consecutive weeks, followed by bare Descemet's therapeutic lamellar keratoplasty (LKP) with the maintenance of antiacanthamoeba treatment to control the infection. In the late postoperative period, visual rehabilitation was obtained by insertion of implantable Collamer lens (ICL) with her final visual outcome was 20/30. For acanthamoeba keratitis, early bare Descemet's therapeutic LKP has a better outcome in comparison to late penetrating keratoplasty in terms of infection eradication and globe preservation. After removal of all sutures, the refractive error can be corrected with photorefractive procedures as well as ICL.

Clinical features and outcomes of Acanthamoeba keratitis in a tertiary hospital over 20- year period.

PURPOSE: To analyze the outcomes of Acanthamoeba keratitis (AK) in terms of different clinical presentations in a tertiary hospital in Taiwan over a 20- year period. METHODS: This is a retrospective case series. Patients with AK diagnosed at the National Taiwan University Hospital between January 1996 and December 2015 were identified. A diagnosis of AK was made on the basis of positive Acanthamoeba smear/cultures or pathological identification of Acanthamoeba cysts on keratoplasty specimens. Patient demographics, clinical presentations, treatment courses, and final visual outcomes were collected and analyzed. Visual acuity, postoperative complications and graft survivals were measured as outcomes. RESULTS: Of the 62 patients with AK in our study, 64.5% were medically treated while 35.5% underwent surgical treatment. In those with ring infiltrate, 52.4% patients could be successfully treated with medications. In eyes receiving penetrating keratoplasty, postoperative complications were more common in therapeutic penetrating keratoplasty (TPK) than those in optical penetrating keratoplasty (OPK) group (82.4% versus 40%, p = 0.04). The graft size was larger in TPK than that in OPK group (8.56 versus 7.83 mm, p = 0.002). Furthermore, post-operative glaucoma, which was the major complication, was found to be associated with larger graft size (p = 0.02) and dilated pupil/iris atrophy (p = 0.01). CONCLUSION: Even in advanced cases with ring infiltrate, eradication of infection with anti-amoebic drugs is possible. In those requiring keratoplasty, the surgical timing should be made meticulously considering graft size and signs of dilated pupil/iris atrophy in terms of post-operative glaucoma.

Demographic and socioeconomic barriers and treatment seeking behaviors of patients with infectious keratitis requiring therapeutic penetrating keratoplasty.

Purpose: To understand demographic and socioeconomic barriers and treatment-seeking behaviors of patients with infectious keratitis requiring therapeutic penetrating keratoplasty (TPK) in a developing country. Methods: This prospective non-comparative questionnaire- based study included all patients presenting to Aravind Eye Hospital, Madurai with infectious keratitis that eventuated to TPK between November 2015 and October 2016. A structured questionnaire was administered on post-operative day 3 to collect data on the demographic details, predisposing factors, prior treatment received, and treatment expenditures. Results: In total, 227 patients underwent TPK between November 2015 and October 2016 for infectious keratitis. The majority of patients were males (n = 132, 58.1%), illiterate (n = 129, 56.8%), and had a family monthly income of less than INR 6000 (n = 142, 62.5%). Most of the patients (n = 163, 71.8%) had prior treatment with an ophthalmologist before presenting to our hospital. The mean distance travelled to reach our centre was 269.2 ± 298.5 km. The mean duration of disease before the presentation was 20.3 ± 21.1 days. Corneal smear was positive for fungus in 163 (88.1%) and Aspergillus was the most commonly isolated fungi in 55 (41.3%) cultures. The mean total cost of treatment was INR 8752.87 ± 7615.39 per patient. There was a positive correlation between the duration of the disease (rho 0.19, P = 0.0034) and the costs of treatment (rho 0.2, P = 0.0024) with the distance travelled by the patient. Conclusion: Patients who travelled a farther distance had a delayed onset of presentation and spent significantly more than their respective counterparts.

Therapeutic penetrating keratoplasty for acanthamoeba keratitis: a review of cases, complications and predictive factors.

PURPOSE: To review 12 acanthamoeba keratitis (AK) patients who required a therapeutic penetrating keratoplasty (TPK) and determine whether there are factors at the presenting visit that can predict the need for TPK. MATERIALS AND METHODS: This was a retrospective case series. All diagnosed AK patients between January, 2009 and February, 2016 at Wills Eye Hospital, Philadelphia, PA, USA, were enrolled. Information regarding demographics, disease manifestation, management and complications was collected. Potential predictors for TPK were obtained by comparing TPK cases with those who were treated medically. RESULTS: Sixty-three eyes from 63 patients were diagnosed with AK. Twelve eyes (19%) required TPK during the course of treatment, and 51 eyes (81%) were treated medically. Reasons for performing TPK included medically non-responsive ulcer in seven eyes (58%), perforated ulcer in three eyes (25%) and significant corneal thinning in two eyes (17%). The most common post-TPK complications included graft failure (75%), cataract (50%) and uncontrolled glaucoma required glaucoma surgery (17%). Reactivation of AK was seen in one (8%) patient. Anti-amoebic treatment beginning after 25 days from the start of AK symptoms [odds ratio (OR) = 7.63; confidence interval (CI) = 1.01-55.33; p = 0.041] and poorer presenting vision (OR = 5.42; CI = 1.91-15.36; p = 0.002) were independent predictors of the need for TPK in multivariate analysis. CONCLUSION: TPK is a procedure with significant postoperative complications but is required by some patients with AK. Eyes with higher risk for needing TPK can be identified earlier and thus provided more intensive treatment and closer follow-up care.

The first Acanthamoeba keratitis case in the Midwest region of Brazil: diagnosis, genotyping of the parasite and disease outcome.

We report an Acanthamoeba keratitis case associated with the use of contact lens in a 28-year-old female from Brasília, Brazil. Samples from corneal scraping and contact lens case were used for culture establishment, PCR amplification, and partial sequencing (fragments of ~400kb) of small subunit rDNA; both culture and PCR were positive. The sequence analyses of the cornea and of isolates from the contact lens case showed similarity with the T4 genotype. To the best of our knowledge, this is the first report of T4 Acanthamoeba keratitis case from the Midwest region of Brazil.

The first Acanthamoeba keratitis case in the Midwest region of Brazil: diagnosis, genotyping of the parasite and disease outcome

Abstract We report an Acanthamoeba keratitis case associated with the use of contact lens in a 28-year-old female from Brasília, Brazil. Samples from corneal scraping and contact lens case were used for culture establishment, PCR amplification, and partial sequencing (fragments of ~400kb) of small subunit rDNA; both culture and PCR were positive. The sequence analyses of the cornea and of isolates from the contact lens case showed similarity with the T4 genotype. To the best of our knowledge, this is the first report of T4 Acanthamoeba keratitis case from the Midwest region of Brazil.