Xanthine oxidase enzyme activity in keratoconic corneal epithelium.

PURPOSE: To assess the activity of xanthine oxidase (XO) enzyme in keratoconic corneal epithelium and to evaluate its relationship with the keratoconus (KC) severity. METHODS: This prospective and randomized study included 66 eyes of 54 KC patients who received corneal collagen cross-linking treatment and 43 eyes of 32 patients who underwent photorefractive keratectomy due to their refractive error. During surgical procedures, the corneal epithelium was mechanically scraped and gathered to analyze the XO enzyme activity spectrophotometrically. The KC group was subdivided into three groups (stages 1, 2, and 3) according to the Amsler-Krumeich classification. The results were compared between the KC and the control group and in between KC subgroups. RESULTS: No significant differences in age and gender were found between the KC and control groups (p = 0.064 and p = 0.296, respectively). The mean XO activity levels of the KC and control groups were 173.57 ± 87.61 and 223.70 ± 99.52 mIU/mg, respectively (p < 0.001). In KC group, 33 eyes were at stage 1, 19 were at stage 2, and 14 were at stage 3. No significant difference was observed between KC subgroups regarding XO activity levels (p = 0.681). CONCLUSION: In this study, our findings revealed that ultraviolet-related pro-oxidant XO enzyme may have a role in the etiopathogenesis of KC. Further studies are needed to support our result. CLINICAL TRIALS REGISTRATION: When we started this study in 2018, we did not have a "Clinical Trials Registration." However, we have ethics committee approval (date: 21. 02. 2018/No: 22).

RELATIONSHIP BETWEEN STAGES OF DIABETIC RETINOPATHY AND LEVELS OF BRAIN-DERIVED NEUROTROPHIC FACTOR IN AQUEOUS HUMOR AND SERUM.

PURPOSE: The aim of the study was to determine aqueous humor and serum levels of brain-derived neurotrophic factor (BDNF) in diabetic patients with and without retinopathy. METHODS: The study included diabetic patients with or without retinopathy, who had an indication for cataract surgery. The study groups were diabetic patients without retinopathy (Group 2), with nonproliferative diabetic retinopathy (Group 3), and with proliferative retinopathy (Group 4). To quantitatively determine the amount of BDNF in samples, the RayBio Human BDNF ELISA kit (Norcross, GA), based on an enzyme-labeled immunosorbent assay was used. RESULTS: The median serum BDNF levels were significantly lower in all the study groups than in the control group (P values: 0.038 Group 2, 0.02 Group 3, and 0.002 Group 4). Serum BDNF was lower in Group 4 than in Group 3 (P = 0.030), and in Group 3 than in Group 2 (P = 0.04). The median aqueous humor BDNF levels were significantly decreased in all groups (P values: 0.047 Group 2, 0.021 Group 3, and 0.007 Group 4). There was no significant difference between Groups 2, 3, and 4 (P = 0.214). CONCLUSION: The serum and aqueous humor BDNF levels decreased in patients with diabetes mellitus (DM) before the emergence of clinical signs of retinopathy.

Relationship between tear eotaxin-2 and MMP-9 with ocular allergy and corneal topography in keratoconus patients.

PURPOSE: To analyze the relationship between the seasonal allergic conjunctivitis (SAC), eotaxin-2, matrix metalloproteinase-9 (MMP-9), and the topographical findings in the keratoconus patients. METHODS: Thirty-four eyes of patients without SAC (Group 1), 34 eyes of patients with SAC (Group 2), and 20 eyes of control subjects (control group) were enrolled. Tear samples of the subjects were collected by Schirmer method. Corneal topography parameters, tear MMP-9, and tear eotaxin-2 levels were analyzed. RESULTS: The mean tear MMP-9 levels in Groups 1 and 2 were significantly higher than in the control group (p = 0.004). MMP-9 level exhibited a positive correlation with the keratoconus stage and a negative correlation with the thinnest corneal thickness (r = 0.294, p = 0.018, and r = - 0.302, p = 0.006, respectively). The tear eotaxin-2 level was higher in Group 2 than in Group 1 and control group which is not statistically significant (p = 0.17). CONCLUSION: The tear eotaxin-2 did not exhibit any difference in the presence of keratoconus. The tear MMP-9 level was higher in the keratoconic eyes, and it showed a correlation with the stage of the disease and the corneal thickness.

Tear function and ocular surface changes following corneal collagen cross-linking treatment in keratoconus patients: 18-month results.

PURPOSE: To investigate the long-term effects that CXL has on the tear function and ocular surface in keratoconus. METHODS: Twenty-one consecutive patients (24 eyes) with progressive keratoconus scheduled for CXL were included. All patients underwent the following procedures: conjunctival impression cytology analysis, ocular surface disease index (OSDI) score, tear osmolarity test, Schirmer test, tear film breakup time (TBUT), ophthalmic surface fluorescein (Fl) staining, and topographical corneal evaluation before as well as 3 and 18 months after accelerated CXL. RESULTS: There was no change in the median OSDI score, tear osmolarity test, Schirmer test, and the Fl staining score after CXL. The median TBUT increased from 9.00 s at baseline to 12.00 s at 18 months postoperative (P < 0.001). The cytological features of the temporal and superior bulbar conjunctiva deteriorated at 3 months post-CXL (P < 0.001). An improvement in impression cytology analysis of the temporal conjunctiva was noted at 18-month follow-up (P < 0.001). Significant improvements in the median maximum keratometry and mean keratometry (K-mean) readings were also noted 18 months after CXL (P < 0.001). The changes in the K-mean correlated significantly with the changes in TBUT levels at 18-month follow-up as compared to baseline (r = - 0.688, P < 0.001). CONCLUSIONS: The improvement in TBUT, conjunctival squamous metaplasia, and the goblet cell density indicates a favorable effect of CXL on the ocular surface and tear film in keratoconus, presumably due to the reduced corneal irregularity after CXL.

Color Doppler imaging of ocular hemodynamic changes in patients with rheumatoid arthritis unrelated to disease activity.

We aimed to investigate how orbital blood flow rates in patients with rheumatoid arthritis (RA) are affected by the active and remission phase of the disease. This prospective study included a total of 56 patients with RA (study group) and 24 control individuals (control group). All RA patients were divided into two groups, as active (Group 1) and remission (Group 2) according to the disease activity index (DAS 28) score. For each eye, retrobulbar vascular structures were evaluated [central retinal artery (CRA), posterior ciliary artery (PCA), and ophthalmic artery (OA)], respectively. The peak systolic velocity (PSV) and end-diastolic velocity (EDV) values were obtained for each artery and the vascular resistance index (RI) measurement was calculated. The median RI of the OA was 0.70 (0.57; 0.79) in the control group, 0.77 (0.55; 0.87) in group 1, and 0.73 (0.47; 0.87) in group 2. The median RI in the PCA was 0.70 (0.56; 0.82) in the control group, 0.76 (0.52; 0.88) in the group 1, and 0.74 (0.52; 0.86) in the group 2. The median RI of CRA was 0.73 (0.48; 0.81) in the control group, 0.71 (0.64; 0.81) in group 1, and 0.68 (0.61; 0.85) in group 2. The RI value was a significant difference between control and group 1 (p < 0.05). Active and remission RA patients had different effects on the flow rate of eye blood vessels.

Sterile keratitis after uneventful corneal collagen cross-linking in a patient with Axenfeld-Rieger syndrome.

PURPOSE: To report on a keratoconus (KC) patient with Axenfeld-Rieger syndrome (ARS) who developed sterile keratitis after accelerated corneal collagen cross-linking (CXL). METHODS: An 18-year-old patient with ARS and KC who had previously undergone intrastromal ring segment implantation underwent accelerated CXL (9 mW/cm2 UVA intensity for 10 min). RESULTS: After uneventful surgery, the patient presented with severe photophobia, redness of the eye, and decreased vision 72 h following the procedure. Slit-lamp examination showed anterior multiple superficial stromal infiltrates in the central cornea with an overlying epithelium defect. Due to the lack of pain and absence of any pathogen from corneal samples, a diagnosis of sterile keratitis was considered. A combination of topical antibiotic and corticosteroid regimen was administered. Three months after CXL slit-lamp examination showed a mild stromal scar overlying the central cornea, which did not decrease visual acuity. CONCLUSIONS: The mechanism by which the sterile keratitis occurs following CXL remains unclear. For our case, the reason of post-CXL sterile keratitis could be considered as an immune response due to the staphylococcal antigens. Furthermore, the possible developmental disturbance of corneal stroma in ARS might have contributed to the development of post-CXL sterile keratitis.

An assessment of ocular elasticity using real time ultrasound and ocular response analyzer in active or remission rheumatoid arthritis.

PURPOSE: To investigate the elasticity of ocular structures in patients with rheumatoid arthritis (RA) without ocular involvement. METHODS: The study included 56 RA patients (study group) and 24 healthy volunteers as the control group. The rheumatoid arthritis patients were divided into two subgroups as those in active phase (Group 1, n = 25) or in remission phase (Group 2, n = 31) according to the disease activity index (DAS 28) score. The elastography values of the ratio of orbital fat-sclera (ROF/S) were measured with real-time US elastography, and corneal mechanical values were measured with the Reichert Ocular Response Analyzer in each eye. RESULTS: The mean ROF/S value was 5.2 ± 1.8 in Group 1, 0.7 ± 0.4 Group 2, and 0.6 ± 0.1 in the control group. There was a significant difference between the Group 1 and control group with regard to ROF/S (p < 0.001), but no significant difference was determined between Group 2 and control group (p > 0.05). The mean ROF/S value was a significant difference between the Group 1 and 2 (p < 0.001). ROF/S was significantly correlated with DAS-28 and C-reactive protein (CRP) (r = 0.816, p < 0.001 and r = 0.259, p = 0.006). CONCLUSIONS: ROF/S was significantly increased in patients in the active phase of RA. Findings revealed that ocular tissue structural changes may occur in the active phase and these could be related to ocular complications as a prognostic factor.

A completely human-derived biomaterial mimicking limbal niche: Platelet-rich fibrin gel.

Platelet-rich fibrin (PRF) is a natural biomaterial and has excellent biochemical and physical properties with a history of proven biocompatibility in the field of tissue engineering and regenerative medicine. Recent reports of fibrin-based matrices have offered new opportunities to apply PRF as a supplement for in vitro cell culture. Here, custom-modified human-derived PRF (HPRF) was produced via different centrifugation protocols, then, characterized by morphologically and chemically and utilized as a substrate and as a conditioned medium for limbal explant culture for the first time. It was found that the HPRF released significantly higher levels of growth factors which are essential for epithelial cell growth. The enhanced physicochemical properties of the HPRF were also proven in the limbal explant cultures in terms of cell growth, migration, viability, and stemness in comparison with the conventional limbal explant culture on human-derived amniotic membrane. Consequently, HPRF hydrogels are appealing natural biomaterials for the purpose of mimicking limbal niche and the discovery elucidates this new, xeno-chemical-free, completely human-derived biomaterial can be utilized as a supplement to promote epithelial cell behaviour in vitro.

Shifting of the Line of Sight in Tilted Disk Syndrome.

OBJECTIVES: To investigate the shifting of the line of sight (LoS) and the refractive, topographic, and aberrometric parameters that may be associated with the shifting of the LoS in eyes with tilted disk syndrome (TDS). METHODS: Eighty left eyes of 80 subjects with TDS (Study Group) and 70 left eyes of 70 subjects with myopia and astigmatism (Control Group) were included in this study. Line-of-sight coordinates on the horizontal (x) and vertical (y) axes, refractive, topographic, and aberrometric parameters were evaluated. All parameters were compared between groups, and correlations were analyzed for the study group. RESULTS: In the study group, the LoS significantly shifted to the superotemporal direction compared with the control group (P=0.022 and P=0.008 respectively). The shift on y-axis was correlated with mean cylindrical refractive error (r=-0.283, P=0.011), total root mean square (RMS) (r=0.321, P=0.004), higher-order aberration RMS (r=0.300, P=0.007), vertical coma (r=0.430, P<0.001), and vertical trefoil values (r=-0.455, P<0.001). CONCLUSIONS: Results demonstrated a superotemporal shifting of the LoS in eyes with TDS. As eyes with TDS have an important place among candidates for refractive and multifocal intraocular lens implantation surgeries, this shift must be accounted for to prevent decentralization and provide satisfactory outcomes.

The evaluation of the risk factors for capsular complications in phacoemulsification.

PURPOSE: To determine and quantify the risk factors for disruption of lens capsule integrity during phacoemulsification. METHODS: The medical records of the patients who had undergone phacoemulsification cataract surgery and had a complication associated with lens capsule were reviewed. Consecutive cases were also reviewed in reverse chronological order as a control group. The exclusion criteria were pediatric cataracts, traumatic cataracts and lens dislocation. As a result, 403 uncomplicated and 83 complicated eyes were analyzed. The differences between the complication group and the group without complications regarding the risk factors were shown by employing the Chi-square test and Fischer's exact test. The variables having the level of significance (p < 0.25) after the Chi-square test and Fischer's exact test were enrolled into the multiple stepwise logistic regression analysis. RESULTS: Age (60-69/≤80) (p = 0.017), male gender (p = 0.006), pupil size ≤3 mm (p = <0.001), mature-brunescent cataract (p = <0.001), anterior chamber depth <2.5 mm (p = 0.001), posterior polar cataract (p = 0.006), diabetic retinopathy(p = <0.001), coronary artery disease (p = 0.098) and surgeon factor (junior resident/senior resident, p = 0.015; senior resident/specialist in ophthalmology, p = 0.026; junior resident/specialist in ophthalmology, p = 0.020) were among the factors significantly related to a capsule complication. An Excel program has been developed according to these results to predict the probability of capsule complication. CONCLUSIONS: Higher-risk cases can be predicted preoperatively, thus allowing surgeons to take appropriate precautions, better informing the patient and better selecting the cases especially for trainee surgeons.

Impact of dehydration and fasting on intraocular pressure and corneal biomechanics measured by the Ocular Response Analyzer.

PURPOSE: To investigate the effects of dehydration and fasting on the intraocular pressure (IOP) and corneal biomechanics during Ramadan in healthy subjects. METHODS: A total of 36 healthy fasting male volunteers with a mean age of 32.7 ± 5.1 years (range 28-38 years) were enrolled in the study. A Reichert Ocular Response Analyzer (ORA) was used to measure the corneal resistance factor (CRF), corneal hysteresis (CH), Goldman-correlated IOP (IOPg), and corneal-compensated IOP (IOPcc), additionally IOP with Goldmann applanation tonometer (IOP-GAT) was taken. All measurements were recorded at 8:00 am and 4:00 p.m. during Ramadan and during a 1-month follow-up after Ramadan was over. RESULTS: Statistical analysis demonstrated no difference in the ORA measurements including CH, CRF, IOPcc, and IOPg; CCT and CV values between fasting and non-fasting periods or within a single day (diurnal changes). Nine volunteers (25% of total subjects) were excluded because eyedrops were believed to disrupt the Ramadan fast consequently IOP-GAT could not be measured from these subjects. No statistically significant difference was noted between IOP-GAT and IOPg measurements of twenty-seven subjects at the different periods and time points. CONCLUSIONS: Our results reveal that fasting during Ramadan does not profoundly affect corneal biomechanics and IOP values in healthy volunteers without ocular diseases such as glaucoma. When planning corneal refractive surgery and determining IOP, the ORA measurements can be done safely during a Ramadan fast. Moreover, ORA may be a better alternative for patients that refuse IOP measurement via GAT for examining the accuracy of IOP during fasting. Further studies are needed to better understand the role of these parameters on corneal disease and glaucoma during fasting.

Chiari 1 malformation with optic disc drusen.

A 32 year old female patient with CM 1 diagnosis was referred for the management of papilledema. Ophthalmologic examination revealed normal visual acuity (20/20 in both eyes), normal optic nerve function tests and normal slit-lamp biomicroscopic findings. Fundoscopy revealed bilateral irregular optic nerve heads with blurred margins. B scan ultrasonography (USG) and Spectral domain optical coherence tomography were performed and bilateral optic nerve heads were diagnosed as ODD. We concluded that the pseudopapilledema must be taken into account before making papilledema diagnosis in patients with CM 1 to protect the patients from redundant interventional procedures.

Tear Function and Ocular Surface Alterations After Accelerated Corneal Collagen Cross-Linking in Progressive Keratoconus.

OBJECTIVE: To investigate the alterations in the ocular surface and tear film parameters 3 months after accelerated corneal collagen cross-linking (A-CXL) in progressive keratoconus (KC) patients. METHODS: Twenty-six patients (33 eyes total) with progressive KC were enrolled in this study. All patients were subjected to ophthalmic surface examination, such as OSDI (ocular surface disease index) scoring, the osmolarity tear test, Schirmer test, tear film breakup time (TBUT) analysis, rose bengal (RB) and fluorescein (Fl) ocular surface staining, and conjunctival impression cytology (IC) analysis, respectively. These tests were performed at baseline and 3 months after A-CXL. Nelson's grading system was used to evaluate the cell morphology and goblet cell density. RESULTS: No statistically significant differences in the levels of tear osmolarity, TBUT, Schirmer test, OSDI scoring, and Fl and RB staining between pretreatment and 3 months postoperatively were observed (all P values >0.05). A statistically significant increase in superior (P=0.005) and temporal (P=0.006) IC grading was seen at the postoperative third month compared to pretreatment. CONCLUSIONS: Only metaplastic changes and a reduction in the density of the goblet cells were seen in conjunctival IC, which is probably because of the toxicity of ultraviolet-A 3 months after A-CXL. However, these results do not lead to deterioration in TBUT. In this study, A-CXL has no adverse effect on ocular surface and tear function, which are important for visual quality.

Outcomes of corneal collagen crosslinking using a customized epithelial debridement technique in keratoconic eyes with thin corneas.

The purpose of the study was to evaluate the outcomes and possible complications of CXL performed with customized epithelial debridement technique to keratoconic corneas with the thinnest pachymetry values less than 400 µm. Nineteen eyes of 19 patients were included. The uncorrected (UCVA) and best corrected visual acuity (BCVA), flattest and steepest keratometric (K) readings, central corneal thickness at the thinnest point (t-CCT), endothelial cell density (ECD) were assessed before and 12 months after CXL. The mean UCVA was increased (p = 0.001), while the mean BCVA did not show any difference (p > 0.05). The mean flattest and steepest K readings were decreased (p = 0.001). No change was observed in the mean t-CCT (p > 0.05). The mean ECD was decreased (p = 0.001). The mean pre-CXL and post-CXL percentages of polymegathism and pleomorphism did not show any significant difference (p > 0.05). CXL performed with customized epithelial debridement technique is successful in halting the progression of keratoconus in corneas thinner than 400 µm after 12 months of treatment. However, significant endothelial cell loss can occur after this procedure.

Biomechanical evaluation of cornea in patients with ankylosing spondylitis.

PURPOSE: The aim of this study was to evaluate the corneal biomechanical parameters in patients with ankylosing spondylitis (AS) and to compare them with the healthy subjects. METHODS: Sixty patients with AS (study group) and 60 healthy subjects (control group) were enrolled in this prospective study. The study group was further classified as active (n:30) and inactive (n:30). After detailed ophthalmological examination including intraocular pressure (IOP) measurement with Goldmann applanation tonometer (IOPGAT), corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated IOP (IOPcc), and Goldmann-correlated IOP (IOPg) were measured with the Reichert Ocular Response Analyzer (ORA). Central corneal thickness (CCT) was measured with the Spectral-Domain Optical Coherence Tomography (SD-OCT). RESULTS: The study group's mean CH, CCT, IOPg, and IOPGAT values were lower than the control group (p < 0.05 for all variables). The mean CH, CRF, CCT, IOPg, and IOPGAT values were higher in active patients when compared to the inactive ones (p < 0.001, p < 0.001, p = 0.013, p = 0.021, and p = 0.002, respectively). CONCLUSIONS: AS patients have lower CCT, CH, IOPg, and IOPGAT when compared with healthy subjects. In the active stage of AS, patients present with higher levels of corneal biomechanical parameters with thicker corneas. IOPcc is a more accurate measurement than IOPGAT or IOPg in AS patients.

Can Corneal Biomechanical Properties Give Clues About Elasticity of Optic Nerve Scleral Component in Nonarteritic Anterior Ischemic Optic Neuropathy?

OBJECTIVE: To investigate corneal biomechanical properties among individuals with unilateral nonarteritic anterior ischemic optic neuropathy (NAION) compared to healthy gender- and age-matched subjects. METHODS: The study subjects were separated into 2 groups: 66 eyes of 33 patients with unilateral NAION (study group) and 33 eyes of 33 healthy individuals (control group). Reichert ocular response analyzer (Reichert Ophthalmic Instruments) was used to assess corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated intraocular pressure (IOPcc), and Goldmann-correlated intraocular pressure values. Also, central corneal thickness was measured using Scheimpflug camera combined with a Placido disc corneal topographer (Sirius; Costruzioni Strumenti Oftalmici). RESULTS: Mean CH and median CRF values were significantly lower in the affected eyes (8.8 ± 1.8 mm Hg, 9.4 mm Hg, respectively) and contralateral unaffected eyes (9.1 ± 1.6 mm Hg, 9.8 mm Hg, respectively) of NAION patients than those in the control group (9.9 ± 1.3 mm Hg, 10.4 mm Hg, respectively; all P < 0.017). Mean IOPcc was significantly higher in the affected eyes of NAION patients (19.2 ± 3.5 mm Hg) than in the eyes of control group (17.1 ± 3.6 mm Hg; P = 0.002). CONCLUSIONS: CH and CRF are significantly reduced in patients with NAION, possibly indirectly reflecting structural weakness in the lamina cribrosa.

Corneal Biomechanical Properties in Rheumatoid Arthritis.

PURPOSE: To investigate the variations in biomechanical properties of the cornea in rheumatoid arthritis (RA) patients. METHODS: A total of 53 RA patients, and 25 healthy individuals (control group) were enrolled. Rheumatoid arthritis patients were classified as in active phase (group 1; n=24) or in remission phase (group 2; n=29). Corneal biomechanical parameters including corneal hysteresis (CH), corneal resistance factor (CRF), corneal compensated intraocular pressure (IOPcc), and Goldmann-correlated IOP (IOPg) were measured with the Reichert Ocular Response Analyzer. Topographical measurements, including central corneal thickness (CCT), anterior chamber depth, iridocorneal angle, and corneal volume were measured using a Sirius corneal topographer. RESULTS: The mean CH was 9.43±1.17 mm Hg in group 1, 9.42±1.84 mm Hg in group 2, and 10.47±1.68 mm Hg in the control group (P=0.03). The mean IOPcc was 17.85±3.2 mm Hg in group 1, 17.95±3.49 mm Hg in group 2, and 15.36±3.11 mm Hg in the control group (P=0.008). The CH showed a significant positive correlation with CRF (P=0.000, r=0.809) and CCT (P=0.000, r=0.461), and a significant negative correlation with IOPcc (P=0.000, r=-0.469). CONCLUSIONS: Decrease in the mean CH measurements indicates that ultrastructural changes in the cornea may occur in the active phase, and these changes persist in the remission period. In addition, IOPcc is significantly affected by the corneal biomechanical properties. In RA patients, it is important to control the corneal parameters and IOP measurements against the irreversible changes on the optic nerve.

The effect of antihypertensive therapy on dry eye disease.

CONTEXT: There is a generalization that "antihypertensive (antiHT) therapy causes Dry Eye Syndrome", which has been claimed for years however most of the publications are epidemiological studies. We performed a clinical study to investigate the effects of antiHT agents on tear function. OBJECTIVE: The aim of this article is to evaluate the effects of different classes of antiHT medications on tear osmolarity, ocular surface problems and dry eye symptoms. MATERIALS AND METHODS: Prospective, non-randomized a clinical study. A total of 71 patients who would be initiated antiHT medication due to elevated systemic blood pressure were included in the study. Thirty of these patients were given antiHT drugs containing diuretic (diuretic +), and 41 of them were given diuretic-free drugs (diuretic -). While the number of the patients medicated in the group that received Angiotensin Converting Enzyme inhibitors (ACE inh)/Angiotensin receptor blockers (ARB) (ACE/ARB +) was 29, the number of those medicated in the ACE/ARB-free group (ACE/ARB -) was 42. Ocular surface disease index scores, tear osmolarity, Schirmer I test, tear film break-up time (TBUT), fluorescein (FL) and rose bengal corneal staining patterns of the patients were analyzed. The patients were examined through the repetition of all the tests in the 1st and the 3rd month. RESULTS: The participants (n = 71) comprised 38 males and 33 females with a mean age of 51.8 ± 10.4. When the first (0-1st month) and the third month (0-3rd months) control measurements between diuretics (+) and diuretics (-) groups before and after antiHT therapies were compared, a statistically significant difference was not found in any of the tests applied. When the 0-1st month measurements of ACE/ARB (+) and ACE/ARB (-) groups were compared, it was observed that staining with FL in ACE/ARB (+) group decreased in a statistically significant manner (p = 0.035) and there was a significant increase in TBUT values (p = 0.022). DISCUSSION AND CONCLUSION: The use of antiHT drugs containing diuretic had no adverse effect on the tear function tests, but using drugs that contain ACE/ARB could have a positive impact.

Efficacy and Safety of the Modified Cretan Protocol in Patients with Post-LASIK Ectasia

Objectives: To investigate the clinical efficacy and safety of the modified Cretan protocol in patients with post-laser in situ keratomileusis ectasia (PLE). Materials and Methods: In this retrospective study, 26 eyes of 16 patients with PLE were treated with the modified Cretan protocol (combined transepithelial phototherapeutic keratectomy and accelerated corneal collagen cross-linking). Visual, refractive, tomographic, and aberrometric outcomes and point spread function (PSF) were recorded preoperatively and at 6, 12, and 24 months after treatment. Results: Both uncorrected and best corrected visual acuity were stable at 24 months postoperatively compared to baseline (from 0.89±0.36 to 0.79±0.33 logarithm of the minimum angle of resolution [LogMAR] and 0.31±0.25 to 0.24±0.19 LogMAR, respectively, p>0.05 for all values). The mean K1, K2, Kmean, thinnest corneal thickness, and spherical aberration at baseline were 45.76±5.75 diopters (D), 48.62±6.17 D, 47.13±5.89 D, 433.16±56.86 µm, and -0.21±0.63 µm respectively. These values were reduced to 42.86±6.34 D, 45.92±6.74 D, 44.21±6.4 D, 391.07±54.76 µm, and -0.51±0.58 µm at 24 months postoperatively (p<0.001, p=0.002, p<0.001, p=0.001, and p=0.02, respectively). The mean spherical equivalent, manifest cylinder, Kmax, central corneal thickness, other corneal aberrations (root mean square, trefoil, coma, quatrefoil, astigmatism), and PSF remained stable (p>0.05 for all variables), while anterior and posterior elevation were significantly improved at 24 months postoperatively (p<0.001 and p=0.02, respectively). No surgical complications occurred during the 24-month follow-up. Conclusion: The modified Cretan protocol is a safe and effective treatment option for PLE patients that provides visual stabilization and significant improvement in topographic parameters during the 24-month follow-up. Further studies are needed to support our results.

[Fungal keratitis caused by Scedosporium apiospermum: first report from Turkey]. / Scedosporium apiospermum'a Bagli Fungal Keratit: Ülkemizden Ilk Olgu.

Fungal keratitis, an eye infection with poor prognosis, is difficult to treat and can lead to loss of vision. Among filamentous fungi Scedosporium spp. rarely lead to fungal keratitis. Here we present a case of keratitis caused by Scedosporium apiospermum. A 61-year-old female patient was admitted to our hospital with the complaints of right eye pain and decreased vision after a foreign body trauma to the right eye. The patient was diagnosed as keratitis by biomicroscopic examination. Conjunctival swabs collected from both eyes were inoculated onto sheep blood agar, chocolate agar, eosin methylene blue agar and Sabouraud dextrose agar. Corneal scrapings from the right eye were inoculated onto the same solid media by "C-streak" method, and in brain-heart-infusion broth by immersion. While gram-stained smears of conjunctival swabs showed no significant finding, smears of corneal scrapings revealed abundant neutrophils and profuse septate hyphae. Fungal keratitis was diagnosed and topical enhanced amphotericin B (0.5 mg/ml) therapy was initiated with netilmicin sulfate and oxytetracycline HCl plus polymyxin B sulfate. At the 10th day of therapy a mold growth was detected in corneal scraping cultures and was identified microscopically as S.apiospermum. Based on the relevant literature, therapy was changed to enhanced topical voriconazole (2 mg/ml) applied hourly, plus systemic voriconazole administration. At the third day of treatment, reduction of epithelial defect and decline in the focus of keratitis were observed. In the following days, however, a progression occurred in the focus of keratitis and 5% natamycin ophthalmic suspension was added to the therapy. Since the patient did not respond to any of the medical treatments, therapeutic penetrating keratoplasty was planned; yet, the patient refused the operation and was discharged with her own request. As far as the local literature was concerned, this is the first report of keratitis caused by S.apiospermum in Turkey. Though a very rare causative agent of keratitis, S.apiospermum is generally resistant to antifungal therapy and often require surgical treatment. Especially in patients with predisposing factors, this organism should be kept in mind as a potential causative agent and relevant microbiological examinations should be performed.