Mehmet Erol Can

Thinning of Choroidal Thickness in Patients with Rheumatoid Arthritis Unrelated to Disease Activity

Abstract Purpose: To investigate subfoveal and perifoveal choroidal thickness (CT) in patients with rheumatoid arthritis (RA). Methods: A study group of 117 patients with RA and a control group of 46 age-matched healthy individuals were enrolled in the study. Subfoveal and perifoveal CTs were measured using enhanced depth imaging optical coherence tomography (EDI-OCT). Perifoveal CT was measured 1,500 µm nasally and 1,500 µm temporally apart from the foveal center. Relationship between the disease activity score 28 (DAS-28) and subfoveal CT was also evaluated. Results: The mean subfoveal CT values in the study and control groups were 226.90 ± 43.61 μm and 299.74 ± 48.06 μm, respectively, which made for a statistically significant difference (p < 0.001). Likewise, perifoveal CT values were significantly thinner in the study group when compared with control group. DAS-28 wasn’t correlated with subfoveal CT in the study group. Conclusions: CT was significantly thinner in patients with RA when compared with healthy controls.

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.

Urgent Therapeutic Grafting of Platelet-Rich Fibrin Membrane in Descemetocele.

Purpose: To report the clinical and histopathological results of a novel autologous scaffold grafting, platelet-rich fibrin (PRF) membrane, in cases with descemetocele. Methods: Three patients with severe corneal stromal melting and central descemetocele caused by neurotrophic keratopathy and infective keratitis underwent PRF membrane grafting on the central cornea for the prevention of imminent corneal perforation. After a quiescent 3-month period, penetrating keratoplasty and cataract extraction were performed for visual rehabilitation in 1 patient and host corneal tissue was examined histopathologically. Results: Pain was significantly relieved, conjunctival inflammation was markedly resolved, and the central descemetocele area became thicker with scar formation in all patients. Histopathological examination revealed fibrosis formation over the descemetocele area without any tissue gap. Newly formed tissue containing irregular corneal lamellae covered the fibrosis formation and accounted for the prevention of perforation. Conclusions: Temporary PRF membrane grafting may be an alternative intervention to avoid impending corneal perforation in cases with severe descemetocele.

Choroidal Thickness in Childhood Obesity

BACKGROUND AND OBJECTIVE To evaluate the effects of obesity on choroidal thickness (CT) in childhood. PATIENTS AND METHODS Forty-four patients with obesity (study group) and 42 healthy children (control group) were enrolled in the study. Subjects underwent a complete ocular examination. The mean CT was measured by enhanced depth imaging optical coherence tomography (EDI-OCT). Body mass index (BMI) was calculated. RESULTS Mean BMI value was 31.8 ± 1.9 in the study group and 19.8 ± 4.4 in the control group. The mean subfoveal CT value 385.77 µm ± 6.09 µm in the study group and 348.43 µm ± 73.21 µm in the control group. There was a significant difference between the study and control groups with regard to subfoveal CT (P = .017). Subfoveal CT and BMI were positively correlated (r = 0.288; P = .004). CONCLUSIONS CT increases in childhood obesity. Findings revealed that adiposity causes a significant increase in CT, and it may be related to ocular complications. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:10-17.].

A novel graft option after pterygium excision: platelet-rich fibrin for conjunctivoplasty

PurposeTo compare the surgical results, complications, and recurrence rates of primary pterygium excision with conjunctival autografts (CA) vs platelet-rich fibrin (PRF) grafts.Patients and methodsA total of 35 eyes of 35 patients with primary pterygium were included in the study. The patients underwent excision of pterygium followed by closure of the bare sclera by CA (group 1, n=20) vs PRF grafts (group 2, n=15). The PRF was generated from the patients’ own whole-blood sample by centrifugation and pressing. The surgery times, intra/postoperative complications, recurrence rates of pterygium, and changes in visual acuity (VA) were evaluated and compared within groups.ResultsThe mean follow-up period was 14.3±6.5 months (6–24 months). The mean preoperative and postoperative VAs were same (20/25) (P=0.204). The mean surgery time was shorter in group 2 (22.1±1.9 min) compared to group 1 (33.8±7.8 min) (P=0.001). The recurrence was observed only in one (6.6%) case of group 2, while none of the cases showed recurrence in group 1. Graft loss was observed in 2 (10%) cases in group 1, and 1 (6.6%) case in group 2. No other intra/postoperative complications such as tear in the graft, excessive bleeding, scleral necrosis, graft necrosis, pannus formation, or symblepharon occurred in both groups.ConclusionsThis preliminary study showed encouraging results of the application of PRF for conjuntivoplasty after pterygium excision. The use of PRF in pterygium surgery is a simple, easily applicable, and a promising method with low rates of recurrence and complications.

A Novel Technique for Conjunctivoplasty in a Rabbit Model: Platelet-Rich Fibrin Membrane Grafting

Purpose. To investigate the effect of platelet-rich fibrin (PRF) membrane on wound healing. Methods. Twenty-four right eyes of 24 New Zealand rabbits equally divided into 2 groups for the study design. After the creation of 5 × 5 mm conjunctival damage, it was secured with PRF membrane, which was generated from the rabbits whole blood samples in PRF membrane group, whereas damage was left unsutured in the control group. Three animals were sacrificed in each group on the 1st, 3rd, 7th, and 28th postoperative days. Immunohistochemical (IHC) stainings and biomicroscopic evaluation were performed and compared between groups. Results. PRF membrane generated significant expressions of vascular endothelial growth factor (VEGF), transforming growth factor-beta (TGF-β), and platelet-derived growth factor (PDGF) in the early postoperative period. However, the IHC evaluation allowed showing the excessive staining at day 28, in control group. Biomicroscopic evaluation revealed complete epithelialization in PRF membrane group, but none of the cases showed complete healing in the control group. Conclusions. This experimental study showed us the beneficial effects of the PRF membrane on conjunctival healing. Besides its chemical effects, it provides mechanical support as a scaffold for the migrating cells that are important for ocular surface regeneration. These overall results encourage us to apply autologous PRF membrane as a growth factor-enriched endogenous scaffold for ocular surface reconstruction.

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

&NA; 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. HighlightsInvestigation of xeno‐chemical‐free cell culture systems is a growing area.Mimicking in vivo conditions with biosafe methods is essential for clinical purpose.Choukrouns PRF was first used as substratum and conditioned medium for limbal culture.It promotes epithelial cell growth, migration, viability, and stemness.The applicability of this new concept has to be proven through clinical studies.

Increased Tear Film Osmolarity in Systemic Lupus Erythematosus

Abstract Purpose: To evaluate tear film osmolarity in patients with systemic lupus erythematosus (SLE). Methods: A total of 55 eyes from 55 patients with SLE and 47 eyes from 47 age- and gender-matched healthy individuals were included in this study. Tear film osmolarity was evaluated with a lab-on-a-chip technique (TearLab; TearLab Corporation, San Diego, CA) in SLE patients in comparison with healthy individuals, and results were correlated to clinically available diagnostic tests for dry eye, such as tear film break-up time (BUT), Schirmer’s test, and Ocular Surface Disease Index (OSDI). Results: The mean tear film osmolarity in the SLE patients and healthy individuals was 306.02 ± 13.27 mOsm/L and 300.74 ± 9.11 mOsm/L, respectively, which made for a statistically significant difference (p = 0.020). In the SLE group, tear film osmolarity was negatively correlated with the Schirmer’s test score and the BUT value (r = −0.295 p = 0.029 and r = 0.347 p = 0.009, respectively), whereas tear film osmolarity was not correlated with OSDI score (r = −0.182 p = 0.183). Conclusions: This study revealed that tear film hyperosmolarity and abnormal tear film function are associated with SLE.