1,720,983 research outputs found
Tear Osmolarity Measurements in Dry Eye Related to Primary Sjogren's Syndrome
No full textBackground: To evaluate the tear osmolarity in patients with dry eye syndrome related to primary Sjogren's Syndrome (SS). Materials and Methods: Twenty eyes of 10 patients with dry eye and primary SS (Group 1) and 20 eyes of 20 subjects who do not have dry eye syndrome (Group 2) were included in this cross-sectional study. In all eyes, ophthalmic examination was performed in the same order: International Ocular Surface Disease Index survey, visual acuity assessment, conjunctival hyperemia scoring, tear osmolarity measurement with TearLab (TM) Osmolarity System, tear film break-up time assessment, corneal fluorescein staining scoring, ocular surface Lissamine Green staining scoring, anesthetized Schirmer test. Dry eye severity was graded according to Dry Eye Workshop (DEWS) classification system. Results: Four eyes with grade 1, four eyes with grade 2, seven eyes with grade 3, and five eyes with grade 4 dryness, according to DEWS system, were included. The mean tear osmolarity value was 301.9 +/- 11.40 mOsm/L (range: 290-328) in Group 1, and 294.85 +/- 8.33 mOsm/L (range: 283-311) in Group 2 (p = 0.03). In Group 1, tear osmolarity values were positively correlated with OSDI scores (r(18) = 0.55, r(2) = 0.31, p = 0.01), DEWS classification grades (r(18) = 0.73, r(2) = 0.54, p < 0.01), temporal and total corneal staining scores (r(18) = 0.67, r(2) = 0.44, p < 0.01, and r(18) = 0.51, r(2) = 0.26, p = 0.02, respectively), temporal conjunctival staining scores (r(18) = 58, r(2) = 0.34, p < 0.01); and negatively correlated with anesthetized Schirmer test results (r(18) = -0.62, r(2) = 0.38, p < 0.01) and TFBUT (r(18) = -0.50, r(2) = 0.25, p = 0.02). Conclusions: Tear osmolarity values were found to be greater in patients with dry eye syndrome related to primary SS compared to control subjects, and positively correlated with the severity of dry eye
Update and critical appraisal of the use of topical azithromycin ophthalmic 1% (AzaSite®) solution in the treatment of ocular infections
No full textAzithromycin is an azalide that acts by binding to the 50S ribosomal subunit of susceptible microorganisms and interfering with microbial protein synthesis. Azithromycin is also noted by anti-inflammatory and immunomodulatory activity. AzaSite (R) (Inspire Pharmaceuticals, Inc, Durham, NC) is azithromycin ophthalmic solution, 1% formulated in polycarbophil (the aqueous mucoadhesive polymer contained in DuraSite (R)) that delivers high and prolonged azithromycin concentrations in a variety of ocular tissues, including the conjunctiva, cornea and particularly the eyelid. AzaSite was approved by the Food and Drug Administration (FDA) in the US in 2007, for the treatment of bacterial conjunctivitis caused by susceptible isolates. This article aims to evaluate the peer-reviewed published scientific literature and to define well-established uses of AzaSite eye drops in the field of ocular infections
Clinical anatomy: cornea and ocular surface
Full text linkBackground: The cornea and ocular surface serve as a vital barrier and the eye’s primary refractive medium, requiring precise coordination to maintain transparency, structural integrity, and immune protection. Constantly exposed to environmental stressors, this interface relies on the stability of the tear film, epithelial architecture, mucin layers, and limbal stem cells to preserve function. Disruption in any component can impair vision and increase vulnerability to disease. Advances in imaging and molecular diagnostics have deepened our understanding of these structures, offering new avenues for early detection and personalized treatment strategies. A comprehensive review is needed to integrate recent findings and assess their clinical relevance.
Methods: A targeted literature search was conducted using PubMed/MEDLINE and Google Scholar to identify English-language publications from 1 January 2000 to 30 May 2025. Keywords included “anatomy,” “histology,” “cornea,” “ocular surface,” “epithelium,” “Bowman’s layer,” “stroma,” “Descemet’s membrane,” “endothelium,” “conjunctiva,” “lacrimal functional unit,” and “eyelids.” Studies were selected irrespective of design, and reference lists of included articles were manually screened for additional relevant sources.
Results: Eighty-six publications were reviewed. Findings highlight that the cornea and ocular surface constitute an integrated anatomical and physiological continuum essential for optical clarity, visual acuity, and ocular health. This dynamic unit comprises the cornea, conjunctiva, tear film (mucin, aqueous, and lipid layers), meibomian glands, goblet cells, and the limbal stem cell niche. Collectively, these elements provide lubrication, immune defense, epithelial homeostasis, and structural integrity. Disruption in any component—such as in dry eye disease, limbal stem cell deficiency, or meibomian gland dysfunction—can precipitate epithelial breakdown, neovascularization, or stromal scarring, ultimately compromising vision. Recognizing this interdependence has reframed ocular surface disease as a multifactorial condition rather than an isolated disorder. A comprehensive understanding of the structural and immunological dynamics of this system is therefore critical for refining surgical strategies and developing targeted therapies.
Conclusions: The cornea and ocular surface components function synergistically to maintain a transparent, stable refractive surface essential for vision. Their coordinated roles in protection, lubrication, immune defense, and tissue repair reveal the importance of anatomical understanding for developing targeted therapies and improving clinical outcomes. A comprehensive understanding of this anatomy is essential for clinicians and researchers aiming to develop more precise therapeutic strategies and surgical techniques to enhance patient outcomes and preserve visual function. Future research should focus on advancing regenerative strategies and personalized treatments to address complex ocular surface disorders more effectively
Collagen Cross Linking in the treatment of Corneal Ectatic Diseases
No full textCollagen crosslinking has been wily used in ectaie disease of the cornea This method causz phoopnlymerisation of the stromal collagen fibers with the combined effecl of the pholosensitizing eubstance riboflavin and ultraviolet A (UVA) beal. After removal of ihe crnic t epithelium ve saturation with riboflavin drops, 3 mW/cm(2) UVA (total 5,4J/cm(2) surface dosage is applied for 30 iinnlure As a re ults of a phocoxijdative miechanis (hat ie desati flationI, inra fibrillary covalent bonds increase After the treatmen new collagen with thicker diameter and esistance to enzymati degradation is formed. By this way, freezing' h stal ri! lagen and ntrease in conical biomechanical stability are aimed, Beside keratocoinus and iantroenic keratectasia. this treatment has been tried for reinforcing ihe effect of intracorneal rings, treat dcnt of coruea I elt moig. uleus keraopathy re hydrops. Immediately after the Irema lt, all-most complete loss of keratocytes in the bateior and mid. stoma and stromal edemna are Sen At the postoperative 3d month, keraoceytes begin to regenerate and edema bepiti to disoappear the cull density increase progressively in the pesioperadve period and around 6th month. tellneroion of the keranxytes is complete, together with the increase in the srmal fiber densicy The mean treatment depth is 320 cm, After treatment in sroma thicker than 400 pmrm, enrt lhe lital damage is not seen Together with the topographic decrease in mean keraiometv stle approximately 25 D decrease in mean spherical equivalent, improvement io nMorplolgical symnmeiry and decrease in corneal abenations were detected
Wide-field vitreoretinal surgery in eyes with Boston type 1 keratoprosthesis
No full textPurpose Vitreoretinal surgery in eyes with Boston type 1 keratoprosthesis (KPro) is challenging due to narrow optic of the KPro. This study analyzed the results of pars plana vitrectomy (PPV) using a wide-field imaging accessory, Resight (R) 700 Fundus Viewing System (Carl Zeiss Meditec, Inc., Germany), for better intraoperative peripheral retinal imaging. Methods In this retrospective case series, KPro patients who underwent simultaneous or sequential PPV at Dokuz Eylul University Hospital between June 2010 and January 2020 were evaluated in terms of anatomic and visual prognoses, as well as KPro- and PPV-associated complications. Results Among 9 KPro eyes that necessitated vitreoretinal surgery, 3 (33.3%) underwent simultaneous KPro and PPV due to proliferative vitreoretinopaties; 6 (66.7%) underwent PPV for retinal detachment or suprachoroidal hemorrhage that appeared after KPro surgery. Retina could be attached in 7 eyes (77.8%), and vision improved in 3 eyes (33.3%). In 1 eye, injected silicone oil moved to subconjunctival area through glaucoma drainage device. Conclusion In eyes with a Boston KPro, wide-angle viewing systems helped handling peripheral retinal problems successfully during PPV, with no observed inadequacy of imaging. Despite anatomical success in most cases, visual prognosis depends on vitality of the macula and the optic disc
Six-month longitudinal analysis of visual, tomographic, and densitometric changes after corneal collagen cross-linking in keratoconus
Full text linkBackground: Keratoconus is a progressive corneal ectasia commonly treated with corneal collagen cross-linking (CXL) to halt further progression. Although transient anterior stromal haze frequently develops after CXL, its impact on visual recovery remains unclear. This study aimed to examine the correlation between postoperative changes in corneal densitometry, visual acuity, topography, and pachymetry in eyes with keratoconus undergoing CXL.
Methods: This retrospective study included eyes with progressive keratoconus undergoing epithelium-off accelerated CXL. Pre- and postoperative assessments included measuring corrected distance visual acuity (CDVA), manifest refraction, and slit-lamp biomicroscopy examination, along with Pentacam HR imaging. Densitometry was quantified across three stromal depths and four annular zones. Follow-up evaluations were performed at day 1, week 1, and months 1, 3, and 6 post-CXL.
Results: Twenty-four eyes from 24 patients with progressive keratoconus (median age, 21.9 years; 79.2% male) were evaluated over a six-month period following CXL. At six months significant improvements were observed in CDVA, accompanied by reductions in flat keratometry, central corneal thickness, and thinnest pachymetry (all P < 0.05). Corneal densitometry increased significantly at one month and partially regressed by six months across all stromal depths and within all concentric annular zones from 0.0–2.0 mm to 6.0–10.0 mm and their corresponding total values (all P < 0.05). Baseline anterior 0.0–2.0 mm densitometry demonstrated a significant inverse correlation with CDVA (r = –0.50, P < 0.05). At one month, CDVA correlated inversely with anterior (r = –0.47, P = 0.003) and mid-stromal (r = –0.58, P = 0.006) 0.0–2.0 mm densitometry, and with anterior 2.0–6.0 mm densitometry (r = –0.45, P = 0.045). By six months, no significant correlations were found between CDVA or absolute keratometric parameters and densitometry at any depth, zone, or total value (all P > 0.05), indicating stabilization of both visual and structural recovery.
Conclusions: Accelerated epithelium-off CXL yielded significant visual and structural improvements in progressive keratoconus over six months. Corneal densitometry followed a characteristic postoperative pattern, with an early peak at one month followed by partial regression. Early stromal backscatter increases were significantly correlated with visual acuity, but these relationships diminished by six months, consistent with recovery of corneal clarity and vision. Longer-term studies are warranted to clarify the prognostic utility of densitometry for visual and tomographic outcomes after CXL
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