Keratocyte Density Research Articles

Long-Term Dehydrated Donor Lamella Survival in Anterior Keratoplasty: Keratocyte Migration and Repopulation of Corneal Stroma.

The aim of this study was to investigate the ability of host keratocytes to colonize the donor lamella transplanted without viable cells (dehydrated) in Descemetic (deep anterior lamellar keratoplasty) and in pre-Descemetic keratoplasty (excimer laser-assisted lamellar keratoplasty). A total of 17 eyes (8 deep anterior lamellar keratoplasties and 9 excimer laser-assisted lamellar keratoplasties) were included in this observational retrospective study; patients underwent ophthalmic examinations, and histological staining was performed ex vivo on the graft in cases of failure. In Descemetic keratoplasty, the long-term survival of the graft is compromised with the central corneal thickness decreasing; corneal pachymetry and in vivo and ex vivo keratocyte densities are significantly reduced (pachymetric reduction of -86 μm in the apex and -87 μm in the thinnest point; density cell reduction of 72% at a depth of 100 μm, 62% at a depth of 250 μm, and -66% at a depth of 400 μm). In pre-Descemetic keratoplasty, clinical complications, reduction of central thickness, or alterations of keratocyte density were not observed. In Descemetic keratoplasty, the migration of the host peripheral keratocytes does not seem enough to repopulate the donor graft, whereas in pre-Descemetic keratoplasty, long-term survival of the graft is good. Keratocyte repopulation was observed only by extensive contact between the donor and host parenchyma.

In Vivo Confocal Microscopic Imaging of the Cornea After Femtosecond and Excimer Laser-assisted Penetrating Keratoplasty.

To examine the microstructure of the cornea after excimer and femtosecond laser-assisted penetrating keratoplasty (ELAK and FLAK) in eyes with Fuchs' dystrophy and keratoconus. Fifty-seven patients were divided into four groups according to corneal disease and surgical technique: Fuchs' dystrophy and ELAK (n = 9; mean age: 70.4 ± 10.6 years); Fuchs' dystrophy and FLAK (n = 13; mean age: 64.3 ± 11.2 years); keratoconus and ELAK (n = 9; mean age: 47.4 ± 13.9 years); and keratoconus and FLAK (n = 9; mean age: 43.5 ± 13.8 years). The control group comprised individuals without ocular disease (n = 17; mean age: 39.9 ± 17.3 years). In vivo investigation of the corneal graft and graft-host junction zone was performed with confocal corneal microscopy. All corneal grafts were transparent and no rejection reaction could be observed during the follow-up period. Confocal microscopy revealed no difference in basal epithelial cell density compared to controls. Anterior keratocyte density was lower than in the control group (818 ± 131 cells/mm(2)) in all four treatment groups (596 ± 174, 586 ± 113, 529 ± 75, 552 ± 91 cells/mm(2)). Langerhans cells could barely be seen; there was no difference in the cutting edge configuration and wound integrity. In vivo confocal microscopy provided evidence that good alignment of graft-host junction could be created with both techniques. The excimer laser was not inferior to the femtosecond laser in performing corneal cuts. The low density of Langerhans cells revealed well-controlled cellular immunological response and sustained corneal integrity in both laser groups.

Ocular Surface Alterations and In Vivo Confocal Microscopic Features of Corneas in Patients With Newly Diagnosed Graves' Disease.

To evaluate the ocular surface characteristics and corneal microstructure in patients with newly diagnosed Graves disease (GD) with no evidence of active thyroid eye disease (TED). Eighty eyes of 40 patients with newly diagnosed GD and 40 age-matched control subjects were recruited in this cross-sectional study. All participants underwent ocular surface tests in the order of tear break-up time (BUT), lissamine green (LG) staining, Schirmer I test with anesthesia, and ocular surface disease index (OSDI) questionnaire. Basal epithelial cell, keratocyte, and endothelial cell densities and subbasal nerves were evaluated using in vivo confocal microscopy (IVCM). Independent sample t test, χ test, and Mann-Whitney U test were used for statistical analysis. Patients with GD had higher OSDI (5.9 ± 6.6 vs. 1.7 ± 2.4, respectively, P ≤ 0.001) and LG staining scores (0.5 ± 0.6 vs. 0.2 ± 0.4, respectively, P = 0.003), and lower BUT scores (7.3 ± 2.5 vs. 9.9 ± 1.7, respectively, P < 0.001) compared with those of control subjects. Patients with GD had lower mean basal epithelial cell density (3928 ± 657 cells/mm² vs. 4771 ± 622 cells/mm², respectively) and total subbasal nerve density (958 ± 394 cells/mm² vs. 1416 ± 744 cells/mm², respectively) and higher subbasal nerve tortuosity (2.7 ± 0.8 vs. 1.6 ± 0.6, respectively) compared with those of control subjects (P < 0.001). There was a statistically significant negative correlation between the duration of symptoms of hyperthyroidism and BUT (rho = -0.273, P = 0.014) and a positive correlation between LG staining scores (rho = 0.329, P = 0.003). A significant reduction in BUT (rho = -0.238, P = 0.003) and epithelial cell density (rho = -0.174, P = 0.029) and an increase in OSDI scores (rho = 0.328, P = 0.003) were found with increasing exophthalmometry measurements. Ocular surface alterations begin early in the course of Graves disease before the onset of overt TED.

Corneal morphometric predictive models from ametropia to excimer laser treatment

ObjectiveTo develop corneal morphometric models with refractive error in excimer laser surgery. MethodA prospective-longitudinal study was conducted on 78 patients (151 eyes) using the LASIK surgical technique, and 56 patients (111 eyes) with myopic astigmatism using ESIRIS (Schwind-Germany) equipment with pendulous microkeratome. The results were analyzed using descriptive statistics. A NIDEK Confoscan microscope was used to obtain and study the images. ResultsAfter LASIK treatment 84.3% of the variations in epithelium thickness variations were due to the magnitude of refractive error and the epithelium thickness before LASIK treatment. More than two-thirds (68.8%) of the variations in keratocyte density variations in posterior flap and 48.2% of the variations in the anterior retroablation zone were due to the magnitude of the refractive error. Variations of 90% were found in the corneal thickness after LASEK, which were due to the magnitude of the refractive error before LASEK. ConclusionsPredictive models reveal that morphometrical variations depend on the magnitude of the refractive error. These models are very important in the selection of patient for refractive surgery, and also for the specific technique to use.

In vivo corneal confocal microscopic analysis in patients with keratoconus.

To quantify corneal ultrastructure using laser scanning in vivo confocal microscopy (IVCM) in patients with keratoconus and control subjects. Unscarred corneas of 78 keratoconic subjects without a history of contact lens use and 36 age-matched control subjects were evaluated with slit-lamp examination (SLE), corneal topography and laser scanning IVCM. One eye was randomly chosen for analysis. Anterior and posterior stromal keratocyte, endothelial cell and basal epithelial cell densities and sub-basal nerve structure were evaluated. IVCM qualitatively demonstrated enlarged basal epithelial cells, structural changes in sub-basal and stromal nerve fibers, abnormal stromal keratocytes and keratocyte nuclei, and pleomorphism and enlargement of endothelial cells. Compared with control subjects, significant reductions in basal epithelial cell density (5817±306 cells/mm(2) vs 4802±508 cells/mm(2), P<0.001), anterior stromal keratocyte density (800±111 cells/mm(2) vs 555±115 cells/mm(2), P<0.001), posterior stromal keratocyte density (333±34 cells/mm(2) vs 270±47 cells/mm(2), P<0.001), endothelial cell density (2875±223 cells/mm(2) vs 2686±265 cells/mm(2), P<0.001), sub-basal nerve fiber density (31.2±8.4 nerves/mm(2) vs 18.1±9.2 nerves/mm(2), P<0.001), sub-basal nerve fiber length (21.4±3.4 mm/mm(2) vs 16.1±5.1 mm/mm(2), P<0.001), and sub-basal nerve branch density (median 50.0 (first quartile 31.2 - third quartile 68.7) nerve branches/mm(2) vs median 25.0 (first quartile 6.2 - third quartile 45.3) nerve branches/mm(2), P<0.001) were observed in patients with keratoconus. Significant microstructural abnormalities were identified in all corneal layers in the eyes of subjects with keratoconus using IVCM. This non-invasive in vivo technique provides an important means to define and follow progress of microstructural changes in patients with keratoconus.

Changes in Keratocyte Density and Visual Function Five Years After Laser In Situ Keratomileusis: Femtosecond Laser Versus Mechanical Microkeratome

To determine the effects of keratocyte loss on optical properties and vision after laser in situ keratomileusis (LASIK) with the flap created with a femtosecond laser or a mechanical microkeratome. Randomized clinical paired-eye study. Both eyes of 21 patients received LASIK for myopia or myopic astigmatism. One eye of each patient was randomized by ocular dominance to flap creation with a femtosecond laser and the other eye to flap creation with a mechanical microkeratome. Before LASIK and at 1, 3, and 6 months and 1, 3, and 5 years after LASIK, keratocyte density was measured using confocal microscopy, and high-contrast visual acuity and anterior corneal wavefront aberrations were measured by standard methods. At each visit, all variables were compared between methods of creating the flap and to the same variable before treatment using paired tests with Bonferroni correction for multiple comparisons. Keratocyte density in the flap decreased by 20% during the first year after LASIK and remained low through 5 years (P < .001). High-order wavefront aberrations increased and uncorrected visual acuity improved immediately after surgery, but these variables did not change further to 5 years. There were no differences in any variables between treatments. A sustained reduction in keratocyte density does not affect vision or optical properties of the cornea through 5 years after LASIK. The method of creating a LASIK flap does not influence the changes in keratocyte density in the flap.

Modelos predictivos de morfometría corneal a partir de la ametropía a tratar con láser excímer

ObjectiveTo develop corneal morphometric models with refractive error in excimer laser surgery. MethodA prospective-longitudinal study was conducted on 78 patients (151 eyes) using the LASIK surgical technique, and 56 patients (111 eyes) with myopic astigmatism using ESIRIS (Schwind-Germany) equipment with pendulous microkeratome. The results were analyzed using descriptive statistics. A NIDEK Confoscan microscope was used to obtain and study the images. ResultsAfter LASIK treatment 84.3% of the variations in epithelium thickness variations were due to the magnitude of refractive error and the epithelium thickness before LASIK treatment. More than two-thirds (68.8%) of the variations in keratocyte density variations in posterior flap and 48.2% of the variations in the anterior retroablation zone were due to the magnitude of the refractive error. Variations of 90% were found in the corneal thickness after LASEK, which were due to the magnitude of the refractive error before LASEK. ConclusionsPredictive models reveal that morphometrical variations depend of the magnitude of the refractive error. These models are very important in the selection of patient for refractive surgery, and also for the specific technique to use.

In Vivo Confocal Microscopic Changes of the Corneal Epithelium and Stroma in Patients With Herpes Zoster Ophthalmicus

To analyze the density and morphology of corneal epithelial cells and keratocytes by invivo confocal microscopy (IVCM) in patients with herpes zoster ophthalmicus (HZO) as associated with corneal innervation. Prospective, controlled and masked cross-sectional study. setting: Single-center study. Thirty eyes with the diagnosis HZO and their contralateral clinically unaffected eyes, 15 eyes of 15 normal controls. intervention procedures: Invivo confocal microscopy and corneal esthesiometry of the central cornea. Changes in morphology and density of the superficial and basal epithelial cells and stromal keratocytes, and correlation with corneal sensation. The density of superficial epithelial cells in HZO eyes with severe sensation loss (766.5 ± 25.2 cells/mm(2)) was significantly lower than both healthy control eyes (1450.23 ± 150.83 cells/mm(2)) and contralateral unaffected eyes (1974.13 ± 298.24 cells/mm(2)) (P= .003). Superficial epithelial cell size (1162.5μm(2)) was significantly larger in HZO eyes with severe loss of sensation, as compared to contralateral (441.46 ± 298.14) or healthy eyes (407.4± 47.2μm(2); all P < .05). The density of basal epithelial cells, anterior keratocytes, and posterior keratocytes did not show statistical significance between patients, controls, and contralateral unaffected eyes. Changes in superficial epithelial cell density and morphology correlated strongly with corneal sensation. Invivo confocal microscopy reveals profound HZO-induced changes in the superficial epithelium, as demonstrated by increase in cell size, decrease in cell density, and squamous metaplasia. We demonstrate that these changes strongly correlate with changes in corneal innervation in eyes affected by HZO.

In vivo ocular imaging of the cornea of the normal female laboratory beagle using confocal microscopy.

To obtain normative data for the normal laboratory beagle cornea using high-resolution invivo confocal microscopy (IVCM). Sixteen eyes of eight healthy young female intact beagles. The central cornea was imaged using IVCM. Mixed effects linear regression was used for statistical analysis. invivo confocal microscopy allowed detailed visualization and quantification of epithelial cells (superficial epithelial cell diameter: 43.25±6.64μm, basal cell diameter: 4.43±0.67μm), and nerve fibers (subepithelial nerve fiber diameter: 2.38±0.69μm, anterior stromal nerve fiber diameter: 16.93±4.55μm). Keratocyte density (anterior stroma 993.38±134.24 cells/mm(2) , posterior stroma 789.38±87.13 cells/mm(2) ) and endothelial cell density (2815.18±212.59 cells/mm(2) ) were also measured. High-resolution IVCM provides detailed noninvasive evaluation of the cornea in the normal laboratory beagle.

Comparison of corneal keratocytes before and after corneal collagen cross-linking in keratoconus patients.

Keratoconus is a bilateral and asymmetric corneal ectasia. Cross-linking uses ultra-violate rays to enhance corneal tissue. The purpose of this study was to use in vivo confocal microscopy to quantitatively analyze microstructural changes over time, after corneal collagen cross-linking (CXL) in keratoconus patients. In this before-and-after study, a total of 45 keratoconic eyes were selected for cross-linking among patients referred to Al-Zahra ophthalmology clinic during 2013-2014. All patients underwent complete ophthalmologic examinations. Keratocytes and the present of activated keratocytes were calculated preoperatively and at 1, 3, 6, and 12 months postoperatively using confocal microscopy. One year after CXL, best corrected and best uncorrected visual acuity was increased significantly (p < 0.001). Spherical equivalent and spherical refractive errors reduced significantly (p < 0.001). The reduction in density of anterior and mid-stromal keratocytes was significant initially (p < 0.001). During follow-up, the density of keratocytes increased significantly in all layers reaching near normal values by 12 months. The percentage of activated keratocytes showed a significant increase 1 month after cross-linking (p < 0.001) albeit this percent reduced as the corneal healing proceeded by month 12. The endothelial cells showed no significant reduction during the follow-up. Collagen cross-linking-induced significant reduction in keratocyte density. The percent of activated keratocytes increased significantly after cross-linking which showed reduction with improvement of corneal healing. After collagen cross-linking, hyper-reflective structures were observed consistent with the stromal collagen structures. Further studies are needed to assess possible changes on corneal biomechanics. The consistency in corneal endothelium numbers proves the safety of this technique.

Evaluation of Corneal Microstructure in Pseudoexfoliation Syndrome and Glaucoma: In Vivo Scanning Laser Confocal Microscopic Study

Purpose: To quantitatively evaluate corneas of patients with pseudoexfoliation syndrome (PXS) and pseudoexfoliation glaucoma (PXG) using in vivo scanning laser confocal microscopy (IVCM).Materials and Methods: The study population comprised 30 patients with PXS, 30 patients with PXG, and 30 normal control subjects. IVCM of the cornea was performed on all participants using the Rostock Cornea Module of the Heidelberg Retinal Tomograph (HRT). Mean outcome measures included density of basal epithelial cells, endothelial cells, and anterior and posterior keratocytes; and tortuosity and density of subbasal plexus nerves.Results: Mean densities of basal epithelial cells, endothelial cells, anterior and posterior keratocytes, and subbasal nerves differed significantly among the three groups. Subbasal nerve densities were significantly diminished in PXS and PXG patients (12.36 ± 2.89 and 6.8 ± 3.42 mm/mm2, respectively) compared with that of control subjects (16.13 ± 3.42 mm/mm2) (p < 0.05). Mean densities of anterior and posterior stromal keratocytes were significantly lower in PXS and PXG patients compared with control subjects (p < 0.05). Endothelial cell densities were 3073.63 ± 654.49, 2592.60 ± 276.36, and 2110.20 ± 620.53 cells/mm2 for control, PXS, and PXG groups, respectively (p < 0.05). The percentages of endothelial cell polymegathism and pleomorphism were higher in PXS and PXG patients compared with control subjects. Endothelial cell polymegathism and pleomorphism were more frequently associated with PXG.Conclusions: Results of this study demonstrate the existence of alterations in the (i) density of cells in the various layers of the cornea, (ii) cellular configuration of corneal endothelial cells, and (iii) density/diameter of the subbasal nerve plexus in patients with PXS, and that such alterations are common in patients with PXG. It would be beneficial to employ IVCM to assess the severity of pseudoexfoliation keratopathy (PXK).

Decreased keratocyte density and central corneal thickness in primary open-angle glaucoma patients undergoing treatment with topical prostaglandin analogues.

Purpose:To evaluate whether prostaglandin (PG) analogue use is associated with alterations in keratocyte density and central corneal thickness (CCT) in subjects with primary open-angle glaucoma (POAG).Materials and Methods:Thirty-five POAG patients treated with PG analogues for >2 years and 35 control subjects without glaucoma were included in this cross-sectional study. All subjects were underwent CCT measurements using ultrasound pachymetry. Keratocyte densities of each stromal layer were determined by in vivo confocal microscopy. Student's t-test and Chi-square test were used for statistical evaluations. Correlations between keratocyte densities and CCT were analyzed using Pearson's correlation analysis.Results:Keratocyte densities in each stromal layer were significantly lower in glaucoma patients receiving PG analogues as compared to those of controls (P < 0.001). The mean CCT was also lower in glaucoma patients (515.2 ± 18.8 μ) than control subjects (549.6 ± 21.1 μ, P < 0.001). A positive correlation between keratocyte densities in each stromal layer and CCT was observed in POAG patients.Conclusions:Long-term administration of topical PG analogues may adversely influence keratocyte densities and CCT. Further prospective studies are required clarify the relationship between PG analogues and their effects on the cornea.

Mitomycin C application in refractive surgery

Over the years, mitomycin C has been used by refractive surgeons to prophylactically decrease haze after surface ablation procedures and therapeutically in the treatment of preexisting haze. Development of mitomycin C treatments has had a significant role in the revival of surface ablation techniques. We reviewed the literature regarding mechanism of action of mitomycin C, its role in modulating wound healing after refractive surgery, and its safety and efficacy as adjuvant therapy applied after primary photorefractive keratectomy surgery or after photorefractive keratectomy re-treatment after laser in situ keratomileusis and other corneal surgeries and disorders. The drug is a potent mitotic inhibitor that effectively blocks keratocyte activation, proliferation, and myofibroblast differentiation. Many studies have suggested that mitomycin C is safe and effective in doses used by anterior surface surgeons, although there continue to be concerns regarding long-term safety. After initial depletion of anterior keratocytes, keratocyte density seems to return to normal 6 to12 months after the use of mitomycin C when corneas are examined with the confocal microscope. Most clinical studies found no difference between preoperative and postoperative corneal endothelial cell densities when mitomycin C 0.02% was applied during refractive surgery,with exposure time of 2 minutes or less. After approximately 14 years of use, mitomycin C has been found to be effective when used for prevention and treatment of corneal haze.

Characteristics of the cornea in patients with pseudoexfoliation syndrome.

To quantify the morphological alterations in corneal nerve fibers and cells in patients with pseudoexfoliation syndrome (PEX) and their relationship with the presence of hyperreflective endothelial deposits observed using in vivo confocal microscopy. One eye each of 37 patients with PEX and 20 age-matched healthy control subjects was evaluated by in vivo corneal confocal microscopy. Patients with PEX were further classified into two groups: those with and without hyperreflective endothelial deposits. We evaluated the densities of basal epithelial cells, anterior and posterior stromal keratocytes, and endothelial cells and structure of sub-basal nerve fibers. The mean anterior and posterior stromal keratocyte and endothelial cell densities and corneal sub-basal nerve plexus variables were significantly lower in patients with PEX compared with those in healthy control subjects. The mean basal epithelial cell density did not significantly differ. Eyes with PEX presented decreased corneal sub-basal nerve plexus variables and cell densities in all corneas, except for the mean basal epithelial cell density. Further, a trend of lower corneal sub-basal nerve plexus measurements in patients with hyperreflective endothelial deposits compared with those without endothelial deposits was observed.

Preliminary study of the association between corneal histocytological changes and surgically induced astigmatism after phacoemulsification.

BackgroundSurgically induced astigmatism (SIA) was one of the factors that influences the desirable refractive outcome, and it was related to the length, type, location, structure of the incision and to the suture closure technique, etc. The aim was to evaluate the association of corneal histocytological changes with SIA after phacoemulsification.MethodsThe study enrolled 68 cases of cataract patient (68 eyes). Corneal histocytological parameters at corneal incision, central cornea and contralateral incision obtained by confocal microscope through focusing (CMTF) were compared preoperatively and 1 week, 2 weeks, 1 month, 3 months and 6 months postoperatively. These biometric parameters included the endothelial cell density, keratocyte density of posterior stromal layer, and the morphological changes. SIA was calculated by Jaffe’s vector analysis.Results1 From preoperatively to 1 week, 2 weeks, 1 month, 3 months and 6 months postoperatively, the endothelail cell density was decreased significantly (p < 0.05). Keratocyte density of posterior stroma layer was increased significantly only at 1 week, 2 weeks, 1 month, 3 months postoperatively (p <0.05), but not statistically significant (p = 0.173) at 6 months postoperatively compared to preoperative values. 2 The histocytological observations indicated that the morphology changed significantly postoperatively at the corneal incision, including the cell absent area, wave-like area, dot-like and mass-like hyperreflection, stripe-like absent area, in the endothelial layer, and the keratocyte activation, microfolds, irregular hyporeflective or hyperreflective belt, and a little dot-like hyperreflection in the posterior stroma layer. 3 The reduction of the endothelial cell density at the corneal incision at 1 week, 2 weeks, 1 month postoperatively, were positively correlated with SIA (P1 week = 0.003, P2 weeks = 0.003, P1 month = 0.032), while others were not associated with SIA statistically.ConclusionsThe reduction of endothelail cell density and the histocytological changes at the corneal incision were associated with SIA. The underlining mechanism needs further study.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2415-14-134) contains supplementary material, which is available to authorized users.

Aging and corneal layers: an in vivo corneal confocal microscopy study.

To describe age-related changes of different corneal layers using a quantitative analysis of in vivo corneal confocal microscopy. Descriptive observational cross-sectional study. A total of 108 healthy corneas of 108 subjects, distributed in four age categories, underwent in vivo corneal confocal microscopy. The effect of aging on the main features of corneal epithelium, sub-basal nerve plexus, stroma, and endothelium was investigated. Mean diameter of superficial epithelial cells increases with age (0.05μm per year; p < 0.0001). Mean cell density of basal epithelium does not change with age (p = 0.37). The sub-basal nerve plexus fiber number, density, and the number of beadings do not statistically change with age (p = 0.14, p = 0.10 and p = 0.17, respectively). Keratocyte density significantly reduces with age in each stromal layer (p < 0.0001). Endothelial cell count decreases by 10.92 cells/mm(2) per year (p < 0.0001). Endothelial polymegathism index and pleomorphism index do not change with age (p = 0.79 and p = 0.39, respectively). Corneal confocal microscopy allows a non-invasive examination of the living cornea, analyzing the microstructure of each corneal layer. Aging significantly influences the corneal confocal microscopy parameters of individual corneal layers, except sub-basal nerve plexus and basal epithelium.

Preliminary study of the association between corneal histocytological changes and surgically induced astigmatism after phacoemulsification

AbstractPurpose SIA was one of the factors that influences the desirable refractive outcome, and it was related to the length, type, location, structure of the incision and to the suture closure technique, etc. The aim was to evaluate the association of corneal histocytological changes with surgically induced astigmatism (SIA) after phacoemulsification.Methods The study enrolled 68 cases of cataract patient (68 eyes). Corneal histocytological parameters at corneal incision、central cornea and contralateral incision obtained by confocal microscope through focusing(CMTF) were compared preoperatively and 1 week, 2weeks, 1month, 3 months and 6 months postoperatively. These biometric factors included the endothelial cell density, keratocyte density of posterior stroma layer, and the morphological changes. SIA was calculated by Jaffe's vector analysis.Results 1 From preoperatively to 1 week, 2weeks, 1month, 3 months and 6 months postoperatively, the endothelail cell density was decreased significantly(p＜0.05). 2 The histocytological observations indicated that the morphology changed significantly postoperatively at the corneal incision, including the cell absent area, wave‐like area, dot‐like and mass‐like hyperreflection, stripe‐like absent area, in the endothelial layer, and the keratocyte activation, microfolds, irregular hyporeflective or hyperreflective belt, and a little dot‐like hyperreflection in the posterior stroma layer. 3 The reduction of the endothelail cell density at the cormeal incision at 1 week, 2 weeks, 1 month postoperatively, were positively correlated with SIA.Conclusion The reduction of endothelail cell density and the histocytological changes at the corneal incision were associated with SIA.

In vivo confocal microscopic characterisation of the cornea in chronic graft-versus-host disease related severe dry eye disease

AimsTo first describe in vivo confocal microscopic (IVCM) corneal findings in severe dry eye syndrome due to ocular chronic graft versus host disease (cGvHD) after allogeneic stem cell transplantation.MethodsIVCM of...

Confocal Microscopy Analysis of Corneal Changes After Photorefractive Keratectomy Plus Cross-Linking for Keratoconus: 4-Year Follow-up

To analyze corneal confocal microscopy changes after combined photorefractive keratectomy (PRK) plus the cross linking (CXL) procedure. Prospective interventional case series. At the Department of Basic Medical Sciences, Neuroscience, and Sense Organs of the University of Bari, Bari, Italy, 17 eyes of 17 patients with progressive keratoconus underwent confocal microscopy examination before and after 1, 3, 6, 12, 18, and 48 months following PRK plus the CXL procedure. The main outcome measures were mean superficial epithelial cell density; mean basal epithelial cell density; mean anterior, mid and posterior keratocyte density; qualitative analysis of stromal backscatter; sub-basal and stromal nerve density parameters; and mean endothelial cell density. During the 4-year follow-up, the mean superficial epithelial cell density, mean basal epithelial cell density and mean endothelial cell density remained unchanged (P > 0.05). The anterior mid-stromal keratocyte density showed a significant decrease (P < 0.05) as compared with preoperative values, and the posterior stromal keratocyte density showed a significant increase at 1 and 3 months of follow-up. Sub-basal and stromal nerve density parameters were significantly decreased until postoperative month 6 (P < 0.05 at 1, 3, and 6 months) and then tended to increase up to preoperative values by the 18th postoperative month. Corneal changes after the PRK plus CXL procedures seem to be pronounced and long lasting as far as keratocyte density of the anterior and mid stroma is concerned. Sub-basal nerve densities tend to reach preoperative values 6 months after surgery.

Confocal microscopy evaluation of the corneal response following AcuFocus KAMRA inlay implantation.

To describe the corneal appearance on confocal microscopy after AcuFocus KAMRA Inlay (AcuFocus, Inc., Irvine, CA) implantation and evaluate the visual acuity compared to the confocal microscopy data. Twelve eyes of 12 patients implanted with one of three models of the AcuFocus KAMRA Inlay (ACI 7000, 7000T, and 7000PDT) were prospectively evaluated by confocal microscopy 6 months after implantation. Additionally, 4 eyes of 4 patients explanted during the follow-up period were evaluated. Among the eyes implanted, mean epithelial thickness was 54.6 ± 22 μm. The subbasal nerve plexus was detected in 10 patients. The corneal nerves per unit area were 2.73 ± 2.1 sprouts/mm(2). The branch pattern was found in 8 patients. The mean keratocyte density value was 540 ± 210 cells/mm(2). A low grade of keratocyte activation was found in all patients. Among the eyes explanted, the mean wound healing opacity was 1,092.75 ± 1,877.35 μm/pixel. The corneal tolerance to the KAMRA Inlay appeared to be good. The inlay modified the normal structure of the corneal layer, but it was not associated with severe complications of the eye. Keratocyte activation was the finding most associated with a negative visual outcome. Confocal microscopy can be useful to evaluate the long-term evolution of the corneal layer changes following KAMRA Inlay implantation.