[Show abstract][Hide abstract] ABSTRACT: Aciclovir (ACV), valaciclovir (VACV) and famciclovir (FCV) are used for systemic infections caused by herpes virus. In Japan, only topical ACV is permitted for use against herpetic keratitis. We investigated the effectiveness of topical ACV, oral VACV and oral FCV on mouse epithelial herpetic keratitis.
C57/BL76 mice were inoculated with HSV-1 McKrae strain in the cornea. Once infection was confirmed 4 days after inoculation, topical ACV, oral VACV and FCV were started and administered for 5 days. Control groups were given either topical or oral saline. On days 2, 4, 6 and 10 after medication started, tears, eyeballs, and trigeminal ganglia were examined using viral culture and real-time PCR.
Viral culture of tears detected no HSV in the topical ACV group on day 4 after administration start; with similar results for the oral VACV group on day 4; and the oral FCV group on day 6. Real-time PCR of the eyeballs showed significant decrease of HSV DNA copy number in the topical ACV group on days 4 and 6 compared to the topical saline group. Real-time PCR of the trigeminal ganglia showed significant decrease of HSV DNA copy number in the oral VACV group on days 4 and 6, and in the oral FCV group on day 6 compared to the oral saline group.
We suggest that 5-day administration of topical ACV, oral VACV and oral FCV are effective for mouse epithelial herpetic keratitis and sufficiently decrease HSV amounts in the ocular surface and eyeballs.
Preview · Article · Feb 2015 · Japanese Journal of Ophthalmology
[Show abstract][Hide abstract] ABSTRACT: Trigeminal and other ganglia are known as sites of latent infection by herpes simplex virus type 1 (HSV-1). In ophthalmology, HSV-1 remains latent in the trigeminal ganglia, and becomes reactivated by several factors, including stress, thermal stimulation, or immunosuppression, and may lead to herpetic keratitis. The purpose of this study was to demonstrate HSV corneal latent infection using molecular biology and virology techniques.
Six corneas obtained at penetrating keratoplasty were snap-frozen; three of them were with past history of herpetic keratitis. TaqMan Real-time PCR was used to show positive HSV DNA in the corneas. We proved negative homogenate and positive explant virologically. Using real-time RT-PCR, we showed that only latency-associated transcript (LAT) was detected and no transcriptional products of other virus genes (α, β, γ) were detected.
All three corneas with past history of herpetic keratitis had HSV DNA and showed negative homogenate and positive explant. LAT was detected in all three corneas. However, α, β, or γ genes were not expressed. All the results of these corneas were consistent with the conditions of corneal latency. The other three corneas without history of herpetic keratitis showed negative homogenate and negative explant. None of them had LAT.
We have shown a possibility that HSV can latently infect the cornea aside from the ganglion.
No preview · Article · Jan 2015 · Japanese Journal of Ophthalmology
[Show abstract][Hide abstract] ABSTRACT: To investigate the effect of the pigments in colored soft contact lenses (SCLs) on their shape and physical properties.
To make a comparison between clear SCLs and colored ones, we used SCLs made of the same materials and the same size and power, and are approved by the Japanese government. The shapes were evaluated in a saline solution by using a CL image viewer, and the sagittal depth was measured. In addition, we made fragments of SCLs and evaluated their shapes. The case we investigated the fitting pattern of the clear SCL was completely different from that of the colored ones on the same eye. Both lenses had the same parameters, were made of the same materials by the same manufacturer.
There were significant differences in the sagittal depth between the clear and colored SCLs. When the fragments were made, the shapes of some colored SCLs reversed. This phenomenon was not seen in the clear SCLs.
The shapes and fitting pattern of colored SCLs sometimes became different from the clear ones. Colored SCLs should be prescribed by ophthalmologists and checked regularly for problems.
No preview · Article · Oct 2014 · Nippon Ganka Gakkai zasshi
[Show abstract][Hide abstract] ABSTRACT: To investigate the efficacy and safety of Vancomycin Ophthalmic Ointment 1% (Toa Pharmaceutical Co., Ltd, Toyama, Japan) in patients with external ocular infections caused by methicillin-resistant Staphylococcus aureus (MRSA) or methicillin-resistant Staphylococcus epidermidis (MRSE).
A case series.
This study was a multicentre, open-label, uncontrolled study in Japan approved as orphan drug status.
Patients with MRSA or MRSE external ocular infections unresponsive to the treatment of fluoroquinolone eye drops.
Vancomycin Ophthalmic Ointment 1% was administered four times daily. PRIMARY AND SECONDARY OUTCOME MEASURES: The subjective and objective clinical scores and bacterial cultures were collected at days 0 (baseline), 3, 7 and 14. The primary outcome was clinical response evaluation (efficacy rate) determined as complete response, partial response, no response and worsening. Secondary outcome was the eradication of the bacteria. Safety was assessed by adverse events including cases in which neither MRSA nor MRSE was detected.
Twenty-five cases with MRSA (20) or MRSE (5) infections were enrolled. Of these 25 cases, 4 discontinued the treatment due to the negative results for bacterial culture during screening or at baseline. Of the 21 cases with conjunctivitis (14), blepharitis (3), meibomitis (1), dacryocystitis (2) or keratitis (1), 14 (66.7%) cases were evaluated as being excellently (complete response, 2 cases) or well (partial response, 12 cases) treated. The eradication rates were 68.4% in MRSA (13 of 19 cases) and 100% in MRSE (2 of 2 cases). Ten adverse events occurred in 7 (28.0%) of 25 cases at the local administration site.
Vancomycin Ophthalmic Ointment 1% was considered to be useful for the treatment of intractable ocular MRSA/MRSE infections.
[Show abstract][Hide abstract] ABSTRACT: Background
Corneal ulceration leading to perforation is associated with infectious and non-infectious destructive conditions in the cornea. The fibrinolytic (plasminogen/plasmin) system is considered to contribute to tissue remodeling in the wound healing process and it is believed to play an important role in proteolysis and fibrosis. To determine the localization of urokinase-type plasminogen activator (u-PA), u-PA receptor (u-PAR) and α2-antiplasmin (α2AP) in the tissue of a corneal perforation, we investigated immunohistochemical expressions of u-PA, u-PAR, α2AP, CD68, and α-smooth muscle actin (α-SMA) in a patient with corneal perforation that developed from an ulcer of no clear cause.
The patient was a 77-year-old woman who presented with a perforated corneal ulcer in her right eye. The cause of her corneal ulcer was unknown. Double immunohistochemistry was performed for the combinations of u-PA with u-PAR, CD68 or α-SMA and α2AP with CD68 or α-SMA to detect the localization of u-PA and α2AP. u-PA and u-PAR co-localization was seen in the corneal ulceration area. u-PA was mainly observed in CD68-positive cells and in some α-SMA positive cells. On the other hand, α2AP was not expressed in CD68-positive cells, but was expressed in α-SMA positive cells.
We identified expression of the u-PA/u-PAR complex and α2AP in a patient with a corneal ulcer. These two molecules are believed to play a crucial role in inflammatory cell recruitment, ECM synthesis and degradation during corneal wound healing.
[Show abstract][Hide abstract] ABSTRACT: Background/aims:
The novel immunochromatographic assay (ICGA) kit was recently developed to diagnose herpes simplex virus (HSV) infection. This multicentre study aimed to evaluate the value of the ICGA kit for the diagnosis of herpetic epithelial keratitis by comparing it with immunofluorescence assay (IFA) and real-time PCR.
Corneal scrapings were collected from 117 patients, including 77 with herpetic keratitis as their final clinical diagnosis as well as 40 others at 21 facilities. These samples were tested by the ICGA kit, IFA and real-time PCR.
The positive concordance between final clinical diagnosis and ICGA was 46.7% (35/75 cases) and the negative concordance was 100% (39/39). The positive and negative concordance between real-time PCR and ICGA were 57.4% (35/61 cases) and 100% (53/53), respectively. The positive and negative concordance between IFA and ICGA were 61.1% (22/36 cases) and 83.3% (55/66), respectively. In 92 cases where anti-HSV drugs were not prescribed prior to corneal scraping, the positive and negative concordance between final clinical diagnosis and ICGA were 55.0% (33/60 cases) and 100% (32/32), respectively.
The ICGA kit has moderate sensitivity and high specificity, indicating clinical utility in the diagnosis of herpetic epithelial keratitis.
Full-text · Article · Oct 2012 · The British journal of ophthalmology
[Show abstract][Hide abstract] ABSTRACT: Achieving high antibiotic concentrations is important for preventing and treating postoperative infections. However, no study has simultaneously compared the achieved concentrations of moxifloxacin, gatifloxacin, and levofloxacin in the human cornea and aqueous humor. The authors therefore performed a randomized study to determine the concentrations of 0.5% moxifloxacin, 0.3% gatifloxacin, and 0.5% levofloxacin in the corneal tissue and aqueous humor after topical instillation in patients undergoing penetrating keratoplasty.
Patients who required penetrating keratoplasty were eligible for this study. The topical preparations of 0.5% moxifloxacin, 0.3% gatifloxacin, and 0.5% levofloxacin used in the study were preservative free (Japanese formulations). Patients were randomly assigned to one of three sequential drug groups, in which each drug was administered three times before surgery. In each administration cycle, the patients received two drops of each drug at 2-minute intervals. Samples of corneal tissue and aqueous humor were collected during surgery. The concentrations of each drug in the samples were determined by high-performance liquid chromatography.
A total of 63 patients across eight centers in Japan were enrolled in the study. Overall, 61 corneal and 58 aqueous humor samples were evaluated. The concentration (mean±standard deviation) of moxifloxacin in corneal tissues was 12.66±8.93 μg/g, which was significantly higher than that of gatifloxacin (4.71±3.39 μg/g; P<0.0001) and levofloxacin (5.95±4.02 μg/g; P<0.0001). The mean concentration of moxifloxacin in aqueous humor samples was 1.40±1.17 μg/mL, which was significantly higher than that of gatifloxacin (0.65±0.80 μg/mL; P=0.0001) and levofloxacin (0.89±0.86 μg/mL; P<0.05). The sequence of drug administration did not significantly affect the results.
These results show that 0.5% moxifloxacin achieved superior ocular concentration than both 0.3% gatifloxacin and 0.5% levofloxacin.
No preview · Article · Apr 2012 · Advances in Therapy
[Show abstract][Hide abstract] ABSTRACT: To report and compare the outcomes of penetrating keratoplasty (PKP) triple procedures [combined PKP, cataract extraction, and intraocular lens (IOL) implantation] with a 25-gauge (G) system, 20-G system, and without core vitrectomy.
Subjects comprised the following 3 groups: the 25-G group including 12 eyes of 12 patients (4 men and 8 women) that underwent PKP with 25-G core vitrectomy, the 20-G group including 9 eyes of 9 patients (3 men and 6 women) that underwent PKP with 20-G core vitrectomy, and the non-core vitrectomy group including 9 eyes of 9 patients (1 man and 8 women) that underwent PKP without core vitrectomy.
In the 25-G, 20-G, and non-core vitrectomy groups, the success rates of IOL implantation were 91.7% (11 of 12 eyes), 88.9% (8 of 9 eyes), and 66.7% (6 of 9 eyes), respectively; the average operation times were 69 minutes, 82 minutes, and 90 minutes, respectively. The 25-G group showed significantly shorter operation time than the other 2 groups. Although not statistically significant, a higher rate of capsular rupture was seen in the non-core vitrectomy group.
A PKP triple procedure with the 25-G system can be a safe treatment that offers a better success rate of IOL implantation and a significantly shorter operation time.
[Show abstract][Hide abstract] ABSTRACT: To evaluate the diagnostic value of real-time polymerase chain reaction (PCR) for detecting Acanthamoeba in eyes diagnosed with Acanthamoeba keratitis (AK) by conventional tests. In addition, to determine the preoperative prognosis-determining factors in eyes with AK.
Retrospective, cross-sectional study.
A total of 104 eyes of 103 patients who were diagnosed with AK or with bacterial or bacteria-associated keratitis (BK) by conventional tests.
Twenty-nine eyes with AK and 75 eyes with BK were evaluated for Acanthamoeba and bacterial DNA by real-time PCR. The Acanthamoeba copy numbers, bacterial load, and clinical parameters in the patients with AK were assessed for those significantly associated with poor outcome, that is, final visual acuity of <20/50 or requiring keratoplasty, by logistic regression analysis.
Acanthamoeba DNA copy number, bacterial DNA copy number, and odds ratio (OR) for poor prognosis.
The detection of amoebic DNA was 50 times more sensitive by real-time PCR than by conventional cyst counting. The Acanthamoeba copy numbers at the first visit (mean: 4.7×10(5)±3.2×10(5) copies) were significantly correlated with the AK stage, and both were significant risk factors for a poor outcome. The Acanthamoeba DNA copy numbers at the first visit and AK stage had a significantly high risk for poor outcome (OR of Acanthamoeba DNA copy per logarithm of copy numbers: 3.48, 95% confidence interval [CI], 1.04-111.63, P<0.05; OR of AK stage: 2.8 per stage increase, 95% CI, 1.07-7.30, P<0.05, after adjustment of age). In the AK cases with poor outcome, the amoebic DNA was not reduced by more than 90% after 1 month of treatment. The weak amoebic reduction was significantly associated with advanced AK stages or previous use of steroids. Bacterial 16S rDNA was detected in 53.6% of the eyes with AK, but it was not associated with any risk for refractoriness.
Real-time PCR was effective in detecting and managing AK. The Acanthamoeba copy number and AK stage at the first visit were significantly associated with poor outcome.
The author(s) have no proprietary or commercial interest in any materials discussed in this article.
[Show abstract][Hide abstract] ABSTRACT: Using real-time polymerase chain reaction (PCR), we detected Acanthamoeba and monitored the changes in Acanthamoeba DNA copy number over the treatment course in patients suspected of Acanthamoeba keratitis (AK).
Subjects were 6 patients (average age, 26.2 years) suspected of AK at the Kinki University Outpatient Clinic. For detection of Acanthamoeba, patients' corneal scrapings were collected for smear analysis, culture, and real-time PCR. After the diagnosis of AK was confirmed, treatment was initiated based on the quantitative result of the real-time PCR.
Both the smear and culture were positive for Acanthamoeba in 4 cases and negative in 2 cases (agreement in 3 cases and disagreement in 2 cases). By real-time PCR, all 6 cases were positive for Acanthamoeba with an average DNA copy number of 4.8 ± 9.1 × 10 copies per sample. We further monitored the variation in the Acanthamoeba DNA copy number over the treatment course and successfully treated all the patients. DNA copy number provided a parallel with other clinical features of AK.
Real-time PCR can be a useful method for a rapid and precise diagnosis of AK. Moreover, utility of the Acanthamoeba DNA copy number obtained by real-time PCR can help ophthalmologists in making the best treatment decision.
[Show abstract][Hide abstract] ABSTRACT: To understand the current state of severe contact lens (CL)-associated microbial keratitis in Japan.
The survey was conducted by the Japan Contact Lens Society and the Japanese Association for Ocular Infection in 224 facilities from April 2007 to March 2009. Patients who were diagnosed with CL-associated microbial keratitis and hospitalized for treatment were enrolled. Clinical characteristics of the keratitis, microbiologic findings and the status of CL hygiene were studied.
A total of 350 patients were investigated, with an average age of 28.0 (9-90) years. Acanthamoeba was identified in 85 (24.3%) corneal specimens and Pseudomonus aeruginosa in 70 (20.0%) cases. One hundred ninety six (56.0%) patients were frequent replacement soft CL users. Extended wearing of daily-use CLs was found in 77 (22.0%) patients. Only 67 cases maintained good CL hygiene by daily rubbing-washing and the poor CL care situation was reviewed.
The most frequently detected pathogenic microorganism was Acanthamoeba, followed by Pseudomonus aeruginosa. Our survey showed the importance of keeping good CL hygiene by proper lens care, and improvement of CL-related social regulations is urgently needed.
No preview · Article · Feb 2011 · Nippon Ganka Gakkai zasshi
[Show abstract][Hide abstract] ABSTRACT: We detected herpes simplex virus types 1 (HSV-1) and 2 (HSV-2), varicella zoster virus (VZV), and cytomegalovirus (CMV) DNAs in recipient corneal buttons taken at the time of penetrating keratoplasty.
Twenty-seven corneal buttons were obtained from 27 patients (10 men and 17 women), 7 of whom had a history of HSV keratitis. Excised corneal buttons were immediately frozen in liquid nitrogen in the operating theater and then stored at -80°C until DNA extraction. The detection of HSV-1, HSV-2, VZV, and CMV DNAs was carried out by a nested polymerase chain reaction (PCR) method. The genome copy numbers for the nested PCR-positive samples were subsequently quantified by real-time PCR.
HSV-1, HSV-2, VZV, and CMV DNAs were detected in 10, 1, 9, and 2 of the 27 recipient corneal buttons, respectively. HSV-1 or HSV-2 DNAs were also detected in 5 of 7 patients with a history of HSV keratitis. Both CMV-positive patients (patients 2 and 3) had ocular pemphigoid. Among the nested PCR-positive samples, 2 HSV-1, 1 HSV-2, 1 VZV, and 1 CMV sample could be quantified by real-time PCR. Copy numbers ranged from 19 to 928 copies.
All 4 herpesviruses, including CMV, were detected in the corneal buttons. The relationship between CMV in the cornea and ocular diseases of the anterior segment should be further evaluated.
[Show abstract][Hide abstract] ABSTRACT: To detect and quantitate the causative pathogens in patients with corneal ulcer using real-time polymerase chain reaction (PCR) by cycling probe.
Clinical and laboratory study of 40 eyes of 40 patients diagnosed with corneal ulcer. Two methods were used for pathogen detection: bacterial culture and real-time PCR with the patient's corneal scrapings. Probes and primers of real-time PCR were designed to be pathogen specific for simultaneous detection of Staphylococcus aureus, Staphylococcus pneumoniae, Pseudomonas aeruginosa, methicillin-resistant S aureus, Candida species, and Fusarium species. Results by both methods were evaluated and compared.
Of 40 eyes, 20 eyes had the same pathogens detected by both methods and those were S aureus (3 eyes; mean [SE], 3.8 [1.3] x 10(1) copies/sample), S pneumoniae (5 eyes; mean [SE], 5.6 [5.1] x 10(3) copies/sample), P aeruginosa (8 eyes; 5.1 [4.0] x 10(3) copies/sample), methicillin-resistant S aureus (1 eye; 1.0 x 10(2) copies/sample), and Candida species (3 eyes; mean [SE], 8.8 [4.9] x 10(3) copies/sample). Six eyes showed negative results by both methods. Results of both methods disagreed in 14 eyes; specifically, 11 had positive PCR results only, 2 had positive culture results only, and 1 eye had positive results for different pathogens.
The real-time PCR assay can simultaneously detect and quantitate bacterial and fungal pathogens in patients with corneal ulcer. Real-time PCR can be a fast diagnostic tool and may be useful as an adjunct to identify potential pathogens.
No preview · Article · May 2010 · Archives of ophthalmology
[Show abstract][Hide abstract] ABSTRACT: The objective of the study was to compare the intraocular penetration levels of the newer fluoroquinolones, moxifloxacin, gatifloxacin, and levofloxacin in the rabbit's cornea, aqueous humor, and conjunctiva after topical instillation.
0.5% moxifloxacin, 0.3% gatifloxacin, and 0.5% levofloxacin were instilled in random sequence in both eyes of nine New Zealand White rabbits at two-minute intervals. Instillation was repeated every 15 minutes for a total of three drops of each fluoroquinolone per eye. Three additional animals had only moxifloxacin instilled bilaterally using the same schedule. Sixty minutes after the final instillation, the rabbits were sacrificed for determination of corneal, aqueous humor, and conjunctival fluoroquinolone concentrations using high-performance liquid chromatography.
Moxifloxacin achieved significantly higher concentrations than levofloxacin and gatifloxacin in the cornea (P = 0.0102 and P = 0.0006, respectively), aqueous humor (P = 0.0015 and P < 0.0001, respectively), and conjunctiva (P = 0.0191 and P = 0.0236, respectively).
0.5% moxifloxacin eyedrops provided superior intraocular penetration in rabbits' eyes compared with the two other fluoroquinolones, 0.5% levofloxacin and 0.3% gatifloxacin.
[Show abstract][Hide abstract] ABSTRACT: Osteo-odonto-keratoprosthesis (OOKP) is a keratoprosthesis technique in which the patient's own tooth root is used to support an optical cylinder. It was invented by Strampelli in 1963 and modified and established by Falcinelli about 10 years later. This method is particularly useful for restoring sight in end-stage Stevens-Johnson syndrome (SJS) and ocular cicatricial pemphigoid (OCP). We started performing OOKP surgery in June 2003 supported by Dr Christopher Liu of Sussex Eye Hospital, Brighton, UK. Till now, we have performed 4 OOKP surgeries for end-stage SJS and OCP. We modified the original method by using artificial buccal mucous membranes to the bone and buccal mucous membrane defects for better wound healing. Case 1 was a 49-year-old woman (SJS), and the corrected visual acuity was 0.5 in 4 years 8 months. Case 2 was a 68-year-old woman (SJS), and the corrected visual acuity was 0.04 in 3 years 10 months. Case 3 was a 63-year-old man (SJS), and the corrected visual acuity was 0.1 in 3 years 2 months. Case 4 was a 71-year-old woman (OCP), and the corrected visual acuity was 0.04 in 1 year 3 months. Despite some minor optical cylinder troubles such as MRSA colonization, tilting, and buccal mucous coverage, their visual acuities were stable without any serious complications. It was demonstrated that OOKP is useful for visual rehabilitation and durable with minimum eye care for severe ocular surface diseases.
[Show abstract][Hide abstract] ABSTRACT: Herpetic eye diseases exhibit various clinical manifestations making a diagnosis difficult in some patients. We quantitated herpes simplex virus (HSV) genomes in the tear fluid and aqueous humor obtained from patients with various herpetic eye diseases by real time PCR. The resulting amounts of HSV-DNA in herpetic epithelial keratitis (HEK), herpetic stromal keratitis (HSK) in active phase, and persistent epithelial defects (PED) were 3.9 x 10(6) copies (detection rate, 81.1%), 8.9 x 10(5) copies (detection rate, 59.1%), and 9.2 x 10(4) copies (detection rate, 88.9%), respectively. In the tear samples obtained from quiescent phase of HSK and endotheliitis, no HSV-DNA was detected. In the aqueous humor of uveitis patients, HSV-DNA was found 3.8 x 10(5) copies/ml (detection rate, 16.7%). Previous studies have shown that active viral replication is not directly related to the persistent epithelial defects and progressive HSK. A relatively high level of HSV-DNA, however, was detected in the tear samples of these two disease forms, although the source of the viral replication was not identified. These findings might bring new ideas about the mechanisms of developments in HSK and PED.
No preview · Article · Jul 2008 · Seminars in Ophthalmology
[Show abstract][Hide abstract] ABSTRACT: To investigate the mechanism of the refractive effect of orthokeratology by using measurements of the anterior and posterior radii of the corneal curvature and anterior chamber depth with a Pentacam analysis system.
Nine women (18 eyes) with a mean age of 29.6+/-3.8 years and low to moderate myopia (<or=-4.00 diopters [D]) were recruited for a 53-week trial of overnight orthokeratology using RD171K lenses (hexafocon A). After wearing the orthokeratology lenses overnight, subjects were examined during the day. With a Pentacam analysis system, subjects were examined at 2, 4, 8, 12, 24, 36, and 53 weeks for the assessment of the anterior and posterior radii of the corneal curvature and anterior chamber depth.
Myopic refractive error significantly reduced during the trial (P<0.001, analysis of variance). The mean refractive error was -2.85+/-0.46 D at baseline and significantly reduced to -0.28+/-0.65 D at 2 weeks (P<0.01, Bonferroni-Dunn post hoc test). At any week, no significant differences were seen in the central posterior radius of the corneal curvature (P=0.55, analysis of variance) or the anterior chamber depth (P=0.69, analysis of variance). The amount of change in the central anterior radius of the corneal curvature significantly correlated with the change in refractive error at 24 weeks (r=0.57, P<0.05, Pearson correlation coefficient).
Overnight orthokeratology lens wear alters the anterior corneal shape rather than the posterior radius of the corneal curvature and the anterior chamber depth. This finding suggests that the primary factor in the refractive effect of orthokeratology is change in the anterior corneal shape rather than overall corneal bending.
No preview · Article · Jan 2008 · Eye & Contact Lens Science & Clinical Practice
[Show abstract][Hide abstract] ABSTRACT: To report the efficacy of phototherapeutic keratectomy (PTK) and deep lamellar keratoplasty (DLKP) in the treatment of Acanthamoeba keratitis.
Two patients with delayed diagnosis of Acanthamoeba keratitis failed to respond to multiple systemic and topic antiamoebic agents supplemented by twice-weekly corneal scraping. Three weeks into such therapy, one developed a ring-shaped subepithelial infiltration and PTK was performed. The other was treated with DLKP for progressive keratitis that had invaded the midstromal layer after 50 days of medical therapy.
Improvements were observed immediately after the operations and medical therapy was gradually discontinued. Best-corrected visual acuity improved to 20/20 for both patients.
PTK and DLKP were found to be effective surgical procedures, especially for advanced Acanthamoeba keratitis that fails to respond to medical therapy and corneal debridement.