Mehmet Cüneyt Özmen

Neutrophil-to-lymphocyte ratio may predict progression in patients with keratoconus.

Purpose: Neutrophil-to-lymphocyte ratio (NLR) is a new potential predictor of systemic inflammation in several diseases. In this study, we aimed to evaluate NLR in patients with keratoconus. Methods: This cross-sectional observational study included 54 patients with keratoconus and 25 age- and sex-matched control subjects. All participants underwent a detailed ophthalmological examination and corneal topography. The patients were divided into progressive and nonprogressive keratoconus groups on the basis of topographic parameters. Serum samples were obtained from all subjects, and the NLR was calculated. Results: The NLR was 3.27 ± 1.37 in the progressive keratoconus group versus 1.87 ± 0.39 and 1.87 ± 0.52 in the nonprogressive and control groups, respectively (P < 0.01). There was a positive correlation between NLR and progression (P < 0.05). In the receiver-operating characteristic analysis, an NLR ≥ 2.24 predicted the presence of progression with 79% sensitivity and 81% specificity. Conclusions: The NLR is a simple and inexpensive marker of systemic inflammation. The NLR was found to be higher in patients with progressive keratoconus than in the nonprogressive group and controls.

A histological study of rabbit corneas after transepithelial corneal crosslinking using partial epithelial photoablation or ethanol treatment

AIM To evaluate the histological changes after transepithelial corneal crosslinking (CXL) using partial thickness excimer laser ablation or epithelial ethanol application in an experimental rabbit study. METHODS Right eyes of twenty-four rabbits were studied. Four eyes received total epithelial debridement (group I). Four eyes received partial thickness epithelial ablation with excimer laser (group II). Twelve eyes were treated with different durations (30s and 60s) and concentrations (18% to 48%) of ethanol (group III). Riboflavin was applied for 30min intervals along with topical proparacaine drops with benzalkonium chloride, and 370 nm irradiation was performed for 30min, while riboflavin was instilled every 3min. Four eyes (group IV) received 48% ethanol for 30s without riboflavin and irradiation. Eyes were collected after 24h and examined histologically. RESULTS All eyes in group I showed keratocyte loss in the superficial 300 µ of corneal storma. In group II, 1-4 layers of epithelium were preserved and no keratocyte loss occurred. In group III, CXL after treatment with ethanol up to 24% concentration and up to 60s revealed no keratocyte loss. CXL after treatment with 48% and higher ethanol concentrations yielded keratocyte loss in the superficial 200 µ to 300 µ of cornea. CONCLUSION Incomplete excimer laser ablation of the epithelium or treatment with ethanol up to 24% concentration and up to 60s duration yielded no stromal keratocyte loss. To get the same histological appearance seen in epithelial debridement group, partial thickness excimer laser epithelial ablation or ethanol application is not adequate for transepithelial CXL.

In-vivo corneal biomechanical analysis of unilateral keratoconus

AIM To evaluate and compare corneal biomechanical findings measured by ocular response analyzer, topographic and pachymetric findings in patients with unilateral keratoconus patients and healthy controls. METHODS This is an observational, case-control study. Patients with keratoconus in one eye and forme fruste keratoconus in the fellow eye were compared with sex and age matched with controls healthy subjects. All subjects were evaluated with rotating scheimpflug imaging system. The receiver-operating-characteristic curves were analyzed to evaluate the sensitivity and specificity of the parameters. RESULTS Twenty-seven patients with keratoconus in one eye and forme fruste keratoconus in the fellow eye were compared with 40 eyes of 40 normal subjects. Corneal hysteresis (CH) was 8.0±1.7 mm Hg in keratoconus group, 8.3±1.6 mm Hg in forme fruste keratoconus group, and 9.8±1.6 mm Hg in control groups (P=0.54 between keratoconus and forme fruste keratoconus groups, P<0.01 between control group and other groups). Corneal resistance factor (CRF) was 7.1±2.2 mm Hg in keratoconus group, 7.8±1.2 mm Hg in forme fruste keratoconus group and 9.9±1.5 mm Hg in control group (P<0.001 between control group and other groups). Using receiver-operating-characteristic analysis, the area under curve values of the parameters to distinguish forme fruste keratoconus from control subjects were: CH (0.768), CRF (0.866). Best cut-off points were 9.3 mm Hg and 8.8 mm Hg for CH and CRF respectively. CONCLUSION Ocular response analyzer parameters (CH and CRF) are found to be significantly lower in forme fruste keratoconus patients compared to normal control subjects.

Microbiologic Examination of Bandage Contact Lenses Used after Corneal Collagen Cross-linking Treatment

Abstract Purpose: To investigate the agents of bacterial contamination of contact lenses after corneal collagen cross-linking (CCL), and to present the possible changes of ocular flora after riboflavin/ultraviolet A. Methods: Seventy-two contact lenses of patients who underwent CCL and 41 contact lenses of patients who underwent photorefractive keratectomy (PRK) as control group were enrolled to the study. After 48 h of incubation, broth culture media was transferred to plates. Samples were accepted as positive if one or more colony-forming units were shown. Results: There were positive cultures in 12 (16.7%) contact lenses in the CCL group and 5 (12.2%) had positive cultures in PRK group. Coagulase-negative staphlycocci (CNS) were the most frequent microorganism. Alpha hemolytic streptococci and Diphteroid spp. were the other isolated microorganisms. Conclusions: Bacterial colonization can occur during and early after the CCL procedure in epithelial healing. To prevent corneal infections after the treatment, prophylactic antibiotics should be prescribed.

Descemet Membrane Endothelial Keratoplasty with Irregular-Edged Graft: A Salvage Method for Large Radial Graft Tears

Large radial tears of donor Descemet membrane (DM) during the preparation of Descemet membrane endothelial keratoplasty (DMEK) grafts can make the trephination stage impossible because of small graft diameter. This results in irregular-edged grafts. In this study, we report two pseudophakic bullous keratopathy patients who underwent DMEK surgery with irregular-edged Descemet membrane (DM) grafts. Main outcome measures were preoperative and postoperative 1-, 3-, and 6-month best corrected visual acuity (BCVA), endothelial cell density (ECD) and central corneal thickness (CCT). Intraoperative and early postoperative complications were also evaluated. Both irregular-edged grafts were successfully implanted into the anterior chamber, unfolded, and attached to the posterior corneal stroma. Patients’ BCVA at 6 months was 1.0 (Snellen equivalent: 20/20) and 0.6 (Snellen equivalent: 20/32) respectively. Decrease in ECD at the last visit was 27% and 25%. CCT decreased from 723 μm and 850 μm to 530 μm and 523 μm, respectively. No intraoperative complications occurred except for the large radial Descemet membrane graft tears that developed during donor DM stripping. None of the cases needed a rebubbling procedure postoperatively. We have demonstrated that irregular-edged DM grafts can be successfully implanted for DMEK surgery with good clinical outcomes.

Effect of Riboflavin/Rose Bengal-Mediated PACK-CXL on Acanthamoeba Trophozoites and Cysts in Vitro

ABSTRACT Purpose: To evaluate the antiamoebic properties of photo-activated chromophore for keratitis (PACK)–corneal cross-linking (CXL) (PACK-CXL), in combination with riboflavin (0.1 and 0.25%) or rose bengal (0.1 and 0.2%), for treatment of Acanthamoeba trophozoites and cysts. Materials and Methods: Cultures of Acanthamoeba castellanii were grown in a fluid medium at a concentration of 2.7 × 105 cell/ml. PACK-CXL was used on A. castellani cells in combination with either riboflavin (0.1 and 0.25%) or rose bengal (0.1 and 0.2%). Riboflavin-containing wells were irradiated with ultraviolet-A (UVA) light (365-nm wavelength). Rose bengal-containing wells were irradiated with green light (523-nm wavelength). A power density of 9 mW/cm2 for 10 min and total irradiation dose of 5.4 J/cm2 was used for both riboflavin and rose bengal. After UVA and green light irradiation, cell viabilities were evaluated, and percentage of dead cells calculated. Results: No significant amoebicidal activity was observed following PACK-CXL/riboflavin at either concentration. PACK-CXL/rose bengal, however, was observed to be highly effective in eradicating Acanthamoeba cells at either concentration, with no significant difference observed between the two concentrations. The percentage of dead cells was 63% following treatment at either rose bengal concentration. Conclusion: PACK-CXL with rose bengal demonstrated pronounced antiamoebic activity against A.castellanii. Further in vitro and in vivo studies are needed to confirm this finding.

Comparison between clinical outcomes of two different designs of toric multifocal intraocular lenses

To compare the clinical outcomes of plate haptic and open-loop haptic toric multifocal intraocular lenses (IOLs). In this retrospective, comparative clinical trial, two different designs of multifocal toric IOL were implanted in 49 eyes of 38 cases with corneal astigmatism ≥ 0.75 Diopter (D). The cases that underwent AcrySof IQ restore multifocal toric IOL (Alcon, open-loop-haptic) implantation were assigned to Group1 (n=19) and the cases that underwent Acriva Reviol multifocal toric IOL (VSY, plate-haptic) implantation were assigned to Group 2 (n=30). After surgery, the groups were compared in terms of degree of IOL rotation, residual spherical refraction and astigmatism and uncorrected near and distance visual acuity. With regard to the results of postoperative 1st month, 3rd month, 6th month and 1st year, no difference was determined in terms of uncorrected distance visual acuity, spherical equivalent (SE), degree of astigmatism (CYL), degree of rotation, and uncorrected near visual acuity (p>0.05). Significant increase was determined in all postoperative follow-up periods in terms of the distance and near visual acuity as compared to preoperative values (p0.05). Clinical outcomes of plate haptic Acriva Reviol multifocal toric IOL and open-loop haptic Acrysof IQ multifocal toric IOL are similar. Both types of IOL effectively reduce astigmatism and provide satisfactory uncorrected distance and near visual acuities.

Safety of Polyacrylamide 1.5% Left in Anterior Chamber in Combined Phacoemulsification and Pars Plana Vitrectomy Surgery.

ABSTRACT Purpose: To evaluate safety, efficacy and postoperative characteristics of polyacrylamide 1.5% ophthalmic viscosurgical device (OVD) left in anterior chamber during and at the end of combined phacoemulsification and pars plana vitrectomy surgery. Materials and Methods: This prospective study comprised 20 eyes that received combined phacoemulsification and pars plana vitrectomy performed by the same surgeon. Polyacrylamide 1.5% was left in anterior chamber at the end of the surgery. Preoperative and postoperative examinations (4, 12 and 24 hours; 14 days; 1 and 3 months) included measurement of intraocular pressure (IOP), central corneal thickness (CCT), endothelial cell density and assessment of any ocular adverse reactions. Results: Four of the 20 patients (20%) showed increased IOP at hours postoperatively and needed medical treatment for IOP control. There was no significant difference in IOP between the preoperative visit and postoperative 3 months (p > 0.05). CCT measurements were similar between preoperative and postoperative visits (p > 0.05). A mean endothelial cell density loss of 6.7% was observed at postoperative day 14, however there was no change after this visit. Conclusion: Polyacrylamide 1.5% is safe, well-tolerated and protective in eyes undergoing combined phacoemulsification and pars plana vitrectomy.

Reply: To PMID 25255134.

about the prognosis of the patients. In such studies aimed to determine predictive markers by using laboratory results, it should be better to evaluate and compare the value and efficacy of these markers with widely used inflammation markers. Second, in the methods section of the original study, the authors stated that 25 patients with keratoconus were using rigid gas-permeable contact lenses and were asked to discontinue using contact lenses for at least 4 weeks before the topographic examination. However, as is known, the time for contact lens–induced corneal changes to reach a steady state after cessation of lens wear is highly variable. According to a study involving 55 eyes of 28 patients using rigid gaspermeable contact lenses, 31 eyes achieved refractive stability by the sixth week and 24 eyes required more than 6 weeks to achieve stability. And, among the variables examined, including those indicating corneal warpage, the factor that correlated with the required time to refractive stability after discontinuation of rigid gas-permeable contact lens wear was the length of time of contact lens use. The use of rigid gas-permeable contact lenses may lead to patient selection bias. Therefore, it should be better if the authors detailed the patients using rigid gas-permeable contact lenses. Also, this issue should be mentioned as a limitation of the study. Third, it is hypothesized that oxidative by-products released by neutrophils may activate proteolytic enzymes and matrix metalloproteinases which may contribute to progression of keratoconus in the original study. This means that progression of keratoconus is a result of higher levels of neutrophils. It is not clear whether the higher levels of neutrophils are a result of progression or the progression is a result of higher levels of neutrophils, and this is an issue that should be clarified.