Erdafitinib-Induced Bilateral Multifocal Serous Retinal Detachments and Severe Dry Eye Related Unilateral Peripheral Ulcerative Keratitis in a Patient with Metastatic Urothelial Carcinoma.

Background: A case of bilateral multifocal serous retinal detachments and dry eye complicated with unilateral peripheral ulcerative keratitis (PUK) during erdafitinib therapy is described. Case description: A 76-year-old male underwent a baseline examination two months after initiating 8 mg erdafitinib therapy (April 2023) due to metastatic urothelial carcinoma. Left subfoveal serous retinal detachment was observed initially but the treatment was resumed as he was asymptomatic. In May 2023, bilateral multifocal subretinal fluid pockets were identified, and the patient was still asymptomatic. However, in June 2023 he complained of bilateral redness and a stinging sensation in his right eye. Bilateral severe dry eye and right PUK were diagnosed. He was prescribed dexamethasone eye drops and sodium hyaluronate artificial tears for both eyes. One week later corneal staining decreased, and progression of PUK ceased. Erdafitinib therapy was discontinued in June 2023 due to the planned transurethral prostatectomy. By July 2023, after discontinuation of the drug and administration of the topical treatment, the dry eye improved and the PUK became inactive. There was also resolution of subretinal fluid pockets in the right eye and a reduction of subretinal fluid pockets in the left eye. After the reinitiation of erdafitinib therapy, serous retinal detachments recurred in both eyes in September 2023, but both corneas remained stable with topical low-dose dexamethasone, cyclosporine-A and artificial tear usage. Conclusion: Erdafitinib therapy may lead to concurrent anterior and posterior segment complications. Multidisciplinary monitoring is crucial for patients undergoing erdafitinib therapy to prevent possible visual disturbances. LEARNING POINTS: Erdafitinib, a tyrosine kinase inhibitor of fibroblast growth factor receptors 1 to 4, is administered for the treatment of locally advanced, unresectable or metastatic urothelial carcinoma but however is fraught with several systemic and ocular side effects.Concurrent anterior and posterior segment ocular involvement could be encountered in patients undergoing erdafitinib therapy.Maintaining a high level of suspicion and closely monitoring for potential ocular complications through collaborative efforts is essential for all patients undergoing erdafitinib therapy.

TNF-α Inhibitors for the Management of Intractable Corneal Melt: Report of Three Cases and Review of the Literature.

OBJECTIVE: To report three consecutive cases with noninfectious corneal melting, whose disease progression could only be halted with tumor necrosis-α (TNF-α) inhibitor infusion, with a review of the relevant literature. MATERIALS AND METHODS: Patients with toxic epidermal necrolysis, severe alkaline burn, and Sjögren syndrome had experienced severe corneal melting following penetrating keratoplasty, Boston type 1 keratoprosthesis implantation or spontaneously, respectively. Topical autologous serum eye-drops, medroxyprogesterone, and acetylcysteine formulations; frequent nonpreserved lubrication; systemic tetracyclines and vitamin-C supplements; topical and systemic steroids and steroid-sparing agents; surgical approaches including amniotic membrane transplantation, tectonic graft surgery; and tarsorraphy failed to alter the disease courses. RESULTS: Upon consultation with the rheumatology clinic, TNF-α inhibitor infliximab (Remicade; Centocor Ortho Biotech Inc, Horsham, PA) 5 mg/kg infusion was planned for each patient. After 0-, 2-, and 6-week doses, monthly infusion at the same dose was maintained for 12 months because of severe and intractable course of their diseases. Each case showed dramatic improvements in corneal melts; and sterile vitritis in the eye with Boston keratoprosthesis responded, as well. CONCLUSIONS: Inhibiting TNF-α-mediated expression of matrix metalloproteinases responsible for collagen breakdown should be considered in refractory cases, as a means of globe salvage.

A cross-sectional optical coherence tomography study in patients on taxane-based therapy and a case report with the literature review.

PURPOSE: To evaluate the characteristics of macular retinal and subfoveal choroidal changes in patients already on taxane-based therapy by the help of spectral domain optical coherence tomograpy (SD-OCT) and determine the incidence of taxane- related cystoid macular edema (CME). MATERIALS AND METHODS: In this cross-sectional case-control study, 202 patients who received taxane-based therapy due to treatment of various cancer and age and sex-matched 200 healthy control subjects were examined. Only patients who received at least 4 cycles of taxane-based therapy were taken into consideration for the taxane group. Taxane-based therapy was further divided into two subgroups; paclitaxel group (149 patients) and docetaxel group (53 patients). Central macular thickness (CMT) and central subfoveal choroidal thickness (CCT) were measured just once during their ongoing chemotherapy using SD-OCT and enhanced-depth imaging (EDI) OCT by Heidelberg OCT by a single examiner. RESULTS: Patients received a median of 7 cycles (range, 4-26) of paclitaxel or docetaxel and received a total cumulative dose of 852.81 ± 368.82 mg/m2 (range, 300-2310 mg/m2). Though the mean CMT was significantly thicker in the taxane group (224.9 ± 28.4 µm) than the healthy control group (215.9 ± 19.7 µm), there was no statistically significant difference between the paclitaxel (225.3 ± 28.2 µm) and docetaxel (224.2 ± 20.1 µm) groups. On the other hand, the CCT was not statistically significant different between the taxane versus control eyes and paclitaxel versus docetaxel patients. Taxane-related CME was detected only in one patient on paclitaxel. Overall, incidence of taxane-related maculopathy was 0.5% (1/202) of all patients in the taxane group. CONCLUSION: In our group of taxane receiving patients, incidence of taxane-related CME was 0.5%. In light of our study, we believe that clinicians should be alert on the occurence of taxane-related CME and carefully scrutinize the patients whenever any suspicion is arisen.

Comparison of culture media indicates a role for autologous serum in enhancing phenotypic preservation of rabbit limbal stem cells in explant culture.

In this study, we aimed to compare the effects of six different cell culture media and autologous serum (AS) on the phenotypic characteristics of rabbit limbal epithelial stem cells (LESC) cultivated on porous polyethylene terephthalate (PET) membranes. Limbal explants from rabbit corneas were grown on PET membrane inserts in five different media: DMEM-F12 with fetal bovine serum (FBS) (DMEM-F12-FBS), with pluripotin (DMEM-F12-pluripotin) and with autologous serum (DMEM-F12-AS), Epilife, Keratinocyte Serum Free Medium (KSFM) and Defined-Keratinocyte Serum Free Medium. The effects of different media were evaluated by total cell yield from explants, measuring the expression of proteins by immunofluorescence and gene expression by Real Time PCR. In all five media tested, most of the limbal epithelial cells (LEC) which proliferated from explants were positive for cytokeratin (CK) 14 (85-90%), indicating that all five media support the growth of LESC from explants. The expression of differentiation markers; CK 3 and 12 was highest in DMEM-F12-FBS (56%), was lower in Epilife and KSFM (26 and 19%, respectively), with the lowest values (13%) obtained in DMEM-F12-AS. Gene expression of limbal cultures on PET membrane inserts was compared to fresh limbal tissue. In DMEM-F12-FBS, DMEM-F12-pluripotin, and DMEM-F12-AS, expression of potential LESC markers CXCR4 and polycomb complex protein BMI-1 were similar to limbal tissue. DMEM-F12 with 10% AS maintained a higher percentage of potential stem cell marker genes and lower expression of genes involved in differentiation compared to Epilife or KSFM. Our study shows that rabbit LEC can be cultivated on PET inserts using DMEM-F12 with autologous serum without a requirement for amniotic membrane or feeder cells.

Unilateral Adult Xanthogranulomatous Infiltration of the Conjunctiva, Limbus and Sclera Leading to a Combined Ophthalmic Artery and Central Retinal Vein Occlusion.

OBJECTIVE: To describe the features of a female patient with a biopsy-proven xanthogranulomatous infiltration of the conjunctiva, limbus and sclera who had an exudative retinal detachment, combined ophthalmic artery and central retinal vein occlusion unilaterally. METHOD: A-53-year old otherwise healthy woman presenting with a painful visual loss in her right eye underwent an ophthalmic examination, meticulous systemic work-up and histopathologic assessment. RESULTS: Ophthalmic examination revealed multiple subconjunctival masses, upper limbal infiltrations, trace cells in the anterior chamber, pale looking posterior fundus, 360 degree scattered retinal hemorrhages and marked exudative retinal detachment in her right eye. Left eye was completely normal.A biopsy taken from one of the subconjunctival masses demonstrated a diffuse infiltration of the histiocytes and this was interpreted as a xanthogranulomatous infiltration with the help of immunohistochemical staining techniques. CONCLUSION: Present case is the only reported adult case with xanthogranulomatous-like infiltration of the eyeball featuring both anterior and posterior segment involvement without any concomitant major systemic disturbances.

The Effect of Intravitreal Azithromycin on the Albino Newborn Rabbit Retina.

PURPOSE: To evaluate the effect of intravitreal azithromycin on the retina in a newborn rabbit model. METHODS: Twelve, two-week old New Zealand albino rabbits were divided into two groups (six in each). The right eyes of six rabbits received 0.75 mg (0.05 mL) azithromycin and the right eyes of the remaining six rabbits 1.5 mg (0.1 mL) azithromycin intravitreally. Left eyes were served as the control and received the same volume of saline. All eyes were enucleated at the third postinjection week. Retinal histology was examined by light microscopy. Apoptosis of the retinal cells was further evaluated by immunohistochemical staining for caspase-3 and in situ terminal deoxynucleotidyl transferase-mediated biotin-deoxyuridine triphosphate nick-end labeling (TUNEL) of DNA fragments. RESULTS: Light microscopy demonstrated no retinal abnormalities in all eyes. However, retinal nuclear DNA fragmentation was evident in both study groups (33.6% with 1.5 mg and 21.4% with 0.75 mg azithromycin) with the TUNEL method. TUNEL staining ratio was statistically higher only in the second group treated with 1.5 mg azithromycin when compared to the control group (p=0.01 Mann Whitney U test). The ratio of caspase-3 positive cells in the two study groups was 21.5% and 20.2%, respectively. Caspase-3 staining ratio was statistically higher in both study groups when compared to the control eyes (p=0.00, p=0.00 respectively). The difference of TUNEL staining ratio between the two study groups was statistically significant (p=0.028), but there were no statistically significant differences in the two study groups by caspase-3 staining (p=0.247). CONCLUSION: In newborn rabbits, intravitreal azithromycin injection resulted in an apoptotic activity in the photoreceptor, bipolar and ganglion cells. Immunohistochemical analysis suggested that doses of 0.75 mg and 1.5 mg azithromycin, administered intravitreally might be toxic to the newborn rabbit retina.

Corneal recovery in a rabbit limbal stem cell deficiency model by autologous grafts of tertiary outgrowths from cultivated limbal biopsy explants.

PURPOSE: To determine the corneal regenerative capacity of sequentially generated primary, secondary, and tertiary limbal explant outgrowths in a limbal stem cell deficiency (LSCD) surgical model. METHODS: Two-millimeter-long limbal shallow biopsies were surgically excised from the upper quadrant of the right eye of rabbits and set on preserved amniotic membrane for explant culture. After the generation of primary outgrowth, the biopsies were sequentially transferred to new amniotic membrane to generate secondary and then tertiary outgrowths. Eighteen rabbits were subjected to a 360° limbal peritomy extending into the scleral zone and combined with superficial keratectomy of the corneal periphery and thorough mechanical debridement of the central cornea in their left eye. Right eye outgrowths, six of each generation, were engrafted on the ocular surface. Clinical outcomes (neovascularization, corneal clarity, and corneal fluorescein staining) were graded after 6 months. Post-mortem corneas were compared with histology, immunochemistry for p63 and Krt3, ABCG2-dependent dye exclusion, and capacity for outgrowths in explant culture. RESULTS: Immunohistology and western blot of the outgrowths for p63 and Krt3 indicated no differences in expression between the primary and tertiary outgrowths for these two markers of growth and differentiation. Clinically, all rabbits treated with amniotic membrane alone developed severe LSCD. Most rabbits grafted with cell outgrowths from all three outgrowth generations achieved stable (>6 months) recovery of the ocular surface. There were partial failures of grafts performed with two secondary and tertiary outgrowths. However, Kruskal-Wallis statistical analysis of the clinical scores yielded no significant difference between the three groups (p=0.524). Histology showed full anatomic recovery of grafts made with primary and tertiary outgrowths. Krt3 and p63 expression throughout the whole limbal corneal epithelium with primary or tertiary outgrowths was not distinguishable from each other. The percentage of dye-excluding cells present within this zone and the capacity of the explant epithelial outgrowth of the regenerated peripheral corneal zone were also on par with those of the donor corneas. The Krt3-negative cells that characterize the basal epithelial layer of the normal limbus could not be found in any regenerated cornea from the primary to tertiary outgrowths. CONCLUSIONS: Our results demonstrate that in rabbits post-primary explant outgrowths retain the capacity for LSCD recovery found in primary explants.

Nodular Scleritis in Association with Panuveitis in Behçet's Disease.

This case report involves a 32-year-old man with Behçet's disease who had simultaneous bilateral anterior uveitis, unilateral nodular scleritis, and occlusive vasculitis with retinal hemorrhages. Although scleritis is not a classical feature of Behçet's disease, a diagnosis of Behçet's disease should be considered in patients with scleritis.

A 5-year study of adenoviruses causing conjunctivitis in Izmir, Turkey.

Adenoviruses are a common cause of conjunctivitis. Genotypes are diverse and differ according to population and geographical distribution of the virus. There is limited data regarding ocular adenoviral infections and genotype distribution in Turkey. This study aimed to determine the adenovirus genotypes and their epidemiological features among patients with conjunctivitis between 2006 and 2010, in Izmir, Turkey. Adenoviral DNA was detected by PCR in 213 of 488 (44%) of the ocular samples collected from patients with viral conjunctivitis during the 5-year study period. Of these, 101 (47%) were randomly chosen and genotyped by sequence analysis. Seven genotypes were identified, including 3, 4, 8, 11, 19, 37, and 53. Genotype 8 and 4 were the dominant types detected in 67 (66.3%) and 25 (24.7%) of the samples, respectively. Other five genotypes (3, 11, 19, 37, 53) were detected in 9 (8.9%) samples. Genotype and seasonal differences observed throughout the study. Human adenoviruse (HAdV)-8 was the most frequent type, except 2008. The prevalence of genotype 4 increased starting from 2006, became dominant in 2008 and decreased in the following years. The peak season was mostly spring months, although it was possible to detect positive samples throughout the year. In conclusion, genotype 8 followed by genotype 4 was the most frequent adenoviral types causing conjunctivitis during the 5-year study period. Findings suggest that there is a slow shift between genotypes throughout the years.

Evaluation of corneal thickness, anterior chamber depth, and iridocorneal angle following scleral buckling surgery with AS-OCT.

BACKGROUND AND OBJECTIVE: To evaluate the changes in central corneal thickness (CCT), anterior chamber depth (ACD), and iridocorneal angle (ICA) with anterior segment optical coherence tomography (AS-OCT) following scleral buckling surgery. PATIENTS AND METHODS: Thirty-one eyes with rhegmatogenous retinal detachment that underwent scleral buckling were included in this prospective study. Changes in CCT, ACD, and ICA were measured with AS-OCT. RESULTS: There was a significant increase in the CCT at 1 day and 1 week postoperatively. CCT became slightly thinner than the preoperative values at 1 month postoperatively. The ACD was relatively shallow at all visits after the surgery. The decrease in the ICA 0° and 180° values was statistically significant at 1 day, 1 week, and 1 month postoperatively. CONCLUSION: Changes in the CCT and ICA after scleral buckling were mild and almost returned to their preoperative levels within 6 months. However, ACD shallowing persisted even after 6 months.

Effect of silicone oil removal on central corneal thickness.

AIM: To evaluate the effect of silicone oil removal(SOR) on central corneal thickness(CCT) in aphakic and pseudophakic eyes prospectively. METHODS: Patients who underwent SOR surgery between June 2005 - August 2007 were included in this study. Silicon oil was actively removed behind the posterior capsule through the pars plana sclerotomy site (posterior approach) in pseudophakic eyes and through the pupil and the corneal tunnel incision (anterior approach) in aphakic eyes with the 18-gauge cannula. CCT was assessed with Orbscan II corneal topography system preoperatively and at one month and three months postoperatively. A total of 34 eyes of 34 patients (26 males, 8 females) comprised the study group. Mean age was (55.6±12.3) years (Range: 25-80 years). Twenty-six eyes (76.5%) were pseudophakic and 8 (23.5%) aphakic. Mean time between silicone oil injection and removal was (15.1±13.6) months (Range: 5-54 months). At baseline, CCT was 576.4±46.0µm in pseudophakic eyes and 611.6±36.2µm in aphakic eyes. RESULTS: At the first postoperative month CCT was (573.3±40.1)µm and (630.9±72.9)µm in pseudophakic and aphakic eyes respectively. At the third postoperative month, CCT was (582.7±49.5)µm and (614.5±82.4)µm in pseudophakic and aphakic eyes respectively. There was no statistically significant difference in CCT measurements one month and 3 months after SOR when compared to preoperative values in both aphakic and pseudophakic eyes (P>0.05). CONCLUSION: Active SOR either by anterior or posterior approach did not affect the CCT.

Long-term success of ahmed glaucoma valve in refractory glaucoma.

AIM: To evaluate the long-term results and complications of ahmed glaucoma valve (AGV) implantation in refractory glaucoma. METHODS: A retrospective review of 13 patients (13 eyes) with refractory glaucoma who underwent AGV implantation and had a minimum follow-up of 18 months was performed. All patients underwent a complete ophthalmologic examination and intraocular pressure (IOP) measurement before surgery and at 1 month, 3 months, 6 months, 1 year after surgery and yearly afterwards. Complications and the number of antiglaucoma medications needed were recorded. RESULTS: Mean age was 27.3±16.0 years. All eyes (100%) had at least one prior incisional surgery. Mean follow-up was 61.3±30.8 months. IOP was reduced from a mean of 35.0 ±7.0mmHg to 18.2±7.9mmHg at 12 months and to 17.0±4.1mmHg at 96 months (P<0.05) with a lower number of medications from baseline, 76.9% patients required additional procedures to achieve the success criteria set by previously published series. The most common complications were encapculated cyst formation in eight eyes (61.5 %) and tube exposure in four eyes (30.8%). CONCLUSION: Encapsulated cyst formation was the most common complication which hindered succesful IOP control after AGV implant insertion for refractory glaucoma. Despite cyst excision with anti-fibrotic agents, successful IOP reduction was not achieved in 76.9% of the patients without antiglaucoma medication.

[Ocular Surface Reconstruction with Cultivated Limbal Epithelial Cells in Limbal Stem Cell Deficiency: One-year Follow-up Results]. / Limbal Kök Hücre Yetmezliginde Kültüre Edilmis Limbal Epitel Hücreleri ile Oküler Yüzey Rekonstrüksiyonunun Bir Yillik Sonuçlari.

PURPOSE: To evaluate the 1-year follow-up results of cultivated limbal epithelial cell (CLEC) transplantation in unilateral limbal stem cell deficiency (LSCD). MATERIAL AND METHOD: One-year follow-up results of five unilateral LSCD patients who had undergone CLEC transplantation were evaluated. Parameters for this evaluation were: fluorescein staining of ocular surface, corneal vascularization and status of epithelium with slit lamp, and visual acuity. 1.5-mm limbal biopsy was performed from the superior limbus of the healthy eyes, broke into two equal pieces, expanded on human amniotic membrane (hAM) and inserts for 14 days until getting 20 mm in size. CLECs on hAMs were used directly, and cells on inserts were used after detachment procedure. The symblepharon and pannus tissues were removed, superficial keratectomy was performed. CLEC on hAMs were transplanted with the epithelial side up onto the bare corneal stroma, sutured to the conjunctiva with 10-0 nylon sutures. Free CLEC layer from insert was placed on hAM as a second layer, additional hAM was used as a protective layer all over other tissues. RESULTS: Median age was 44.4 years (14-71). The etiology was chemical burn in all patients. Median duration of symptoms was 10 years (2-18), median follow-up period was 12.6 (12-12.5) months. Preoperative best corrected visual acuities (BCVA) were light perception in three patients, counting fingers at 50 cm in one patient and 3/10 in one patient. Visions were improved in all patients. Postoperative BCVA 12 months after the surgery were between counting fingers at 3 meters to 6/10. There was a temporary hemorrhage between the two layers of hAMs in one patient at the early postoperative period. Peripheral corneal vascularization has occurred in three patients, in patient corneal vascularization has reached to the paracentral area. DISCUSSION: CLEC transplantation is an efficient treatment option for unilateral LSCD in mid-long term.

Necrotic arachnidism of the eyelid due to Loxosceles rufescens spider bite.

A 69-year-old woman was awakened with redness and swelling of the left upper eyelid a few days before her presentation. She also noticed a dead spider on her bed. Ophthalmic examination revealed severe left periorbital hyperemia, edema and a wide necrotic area on the upper eyelid. Systemic condition of the patient was well. She was hospitalized with the diagnosis of necrotic arachnidism of the left upper eyelid. Systemic corticosteroid and antibiotic treatment was commenced. No surgical intervention was carried out. A week later, whole upper eyelid was covered with a black eschar. This black eschar shrank with time, and it detached completely within 8 weeks and the lesion healed without a disfiguring scar. Meanwhile, the offending spider was identified as Loxosceles rufescens. Although rare, eyelid may be a biting site for Loxosceles spiders and a favorable result may be obtained with conservative management.

Identification of three novel plasminogen (PLG) gene mutations in a series of 23 patients with low PLG activity.

Inherited severe hypoplasminogenaemia is a multisystemic disorder leading to deficient extravascular fibrinolysis. As a clinical consequence wound healing capacity of mucous membranes is markedly impaired leading to ligneous conjunctivitis and several other manifestations. Here we report the molecular genetic and clinical findings on 23 new cases with severe hypoplasminogenaemia. Homozygous or compound-heterozygous mutations in the plasminogen (PLG) gene were found in 16 of 23 patients (70%), three of which were novel mutations reported here for the first time (C166Y, Y264S, IVS10-7T/G). Compared to 79 previously published cases, clinical manifestations of the current group of patients showed higher percentages of ligneous periodontitis, congenital hydrocephalus, and involvement of the female genital tract. In contrast, involvement of the gastrointestinal or urogenital tract was not observed in any of the cases. Patients originated to a large extent (61%) from Turkey and the Middle East, and showed a comparably frequent occurrence of consanguinity of affected families and a greater female to male ratio than was derived from previous reports in the literature. Individual treatment of ligneous conjunctivitis included topical plasminogen or heparin eye drops, topical or systemic fresh frozen plasma, and surgical removal of ligneous pseudomembranes, mostly with modest or transient efficacy. In conclusion, the present study underscores the broad range of clinical manifestations in PLG-deficient patients with a trend to regional differences. Transmission of genetic and clinical data to the recently established Plasminogen Deficiency Registry should help to determine the prevalence of the disease and to develop more efficient treatment strategies.

Acute vitreomacular traction syndrome after uneventful phacoemulsification.

We prospectively evaluated 59 eyes following uneventful phacoemulsification and intraocular lens implantation with optic coherence tomography at one and seven postoperative days (POD). Acute vitreomacular traction was observed in two eyes (3.3%) at the first POD. Spontaneous resolution occurred in both eyes within one week. The temporary visual loss associated with acute vitreomacular traction syndrome may go unnoticed as visual acuity rapidly improves.

The effect of various alpha1-adrenergic receptor antagonists on pupillary dilation.

We prospectively evaluated the effect of various systemic alpha1 adrenergic receptor antagonists on pupillary dilation in patients with benign prostatic hyperplasia. Patients who are at risk for intraoperative floppy iris syndrome cannot be elucidated simply by judging preoperative dilation.

Conjunctival involvement in chronic recurrent multifocal osteomyelitis.

PURPOSE: To report a case of chronic recurrent multifocal osteomyelitis (CRMO) with conjunctival involvement. METHODS: Retrospective chart review. RESULTS: A 10-year-old girl who complained of fatigue and debilitating pain in both hips and legs for >1 year had recurrent episodes of redness and discharge in both eyes with little response to different topical medications. The diagnosis of CRMO was confirmed with the help of magnetic resonance imaging, bone scan, and bone biopsy results. She had moderate hyperemia and multiple discrete salmon-colored lesions in both palpebral and fornical conjunctivae. Biopsy revealed chronic inflammatory infiltration composed predominantly of lymphocytes forming a follicular pattern. Conjunctival lesions worsened during relapses of skeletal symptoms, improved during remission, and resolved shortly after the initiation of oral prednisolone therapy. No recurrence was observed during 16 months of follow-up. CONCLUSIONS: Salmon-colored conjunctival lesions may accompany CRMO and respond favorably to systemic steroid therapy.

Identification of Acanthamoeba genotype T4 and Paravahlkampfia sp. from two clinical samples.

In this study, two free-living amoebae strains, Acanthamoeba genotype T4 and Paravahlkampfia sp., which were isolated from keratitis cases are presented. While the Acanthamoeba strain was isolated as a single agent, the Paravahlkampfia strain was found together with herpes simplex virus. Neither of the patients were contact lens wearers, but they did have a history of minor corneal trauma. Amoebae were detected on non-nutrient agar covered with Escherichia coli. Based on PCR-amplified 18S rRNA-gene analysis the first isolate was identified as Acanthamoeba genotype T4 and the second as Paravahlkampfia sp. In thermotolerance tests, the maximum temperature at which trophozoites continued to divide was determined as 37 degrees C for this Acanthamoeba strain and 35 degrees C for the Paravahlkampfia strain. To the best of our knowledge, the Acanthamoeba strain described herein is the second molecularly identified Acanthamoeba strain in an Acanthamoeba keratitis patient in Turkey. However, the Paravahlkampfia isolate is believed to be the first strain that has been isolated from a keratitis patient and has been molecularly differentiated from Vahlkampfia.