Mehmet C. Mocan

Morphologic alterations of both the stromal and subbasal nerves in the corneas of patients with diabetes

Purpose: To evaluate the subbasal and the stromal nerves of the corneas of patients with type 2 diabetes with in vivo confocal microscopy and to compare them with those of nondiabetic patients. Methods: Thirty-five corneas of patients with type 2 diabetes and 24 corneas of age-matched control subjects were included in the study. Patients with diabetes were further classified with respect to the stage of retinopathy. Subbasal and stromal nerve plexus morphology and thickness were evaluated with in vivo confocal microscopy. Subbasal long nerve fiber (LNF) and total nerve branch (NB) densities were calculated. Results: The mean stromal nerve thickness was significantly higher in patients with diabetes (8.99 ± 2.32 μm) than that of the control subjects (5.69 ± 1.49 μm; Mann-Whitney U test; P < 0.001). The proportion of curved stromal nerves in patients with diabetes (45.7%) was also higher than that of normal subjects (20.8%; χ2, P = 0.05). Subbasal LNF and NB densities were found to significantly lower in the corneas of patients with diabetes (28.3 ± 10.4 and 39.7 ± 13.2 nerve/mm2, respectively) than those of the control subjects (34.1 ± 5.7 and 58.5 ± 12.4 nerve/mm2, respectively; Mann-Whitney, P = 0.012 and P < 0.001). In addition, the subbasal nerve plexus of patients with diabetes appeared significantly thicker and more tortuous than those of the control subjects (Mann-Whitney, P = 0.002 and P = 0.001). Conclusion: Both stromal and subbasal nerves appear abnormal in the corneas of patients with diabetes. Patients with proliferative diabetic retinopathy show more pronounced nerve alterations than patients who do not have diabetic retinopathy.

Hyaluronic acid coated poly-ɛ-caprolactone nanospheres deliver high concentrations of cyclosporine A into the cornea

The objective of this study was to determine cyclosporine A (Cy A) levels in ocular tissues and fluids after topical administration of poly-epsilon-caprolactone (PCL)/benzalkonium chloride (BKC) nanospheres and hyaluronic acid (HA) coated PCL/BKC nanospheres onto healthy rabbit corneas. Nanospheres were prepared by nanoprecipitation and purified by gradient-rate centrifugation. Cy A (0.1%) in either castor oil solution (group 1), PCL/BKC nanosphere formulation (group 2) or HA coated PCL/BKC nanosphere formulation (group 3) was instilled onto rabbit corneas. Tear samples were adsorbed onto Schirmer tear strips. Cy A concentrations of fluid (blood, aqueous humor, tear) and specimen extracts (cornea, conjunctiva, iris/ciliary body) were determined by high performance liquid chromatography-mass spectrometry (LC-MS). The mean corneal Cy A concentration obtained at 0.5, 1, 2, 4, 8 and 24h following instillation of the formulations ranged between 0.12 and 1.2 ng/mg tissue for group 1, 5.9-15.5 ng/mg tissue for group 2 and 11.4-23.0 ng/mg for group 3 (one-way analysis of variance (ANOVA) and pairwise tests (SNK (Student-Newman-Keuls) and Tukey); p<0.05). Conjunctival Cy A levels of group 2 and 3 were not significantly different at any of the time points tested. However, there was a significant difference between Cy A concentration of castor oil formulation and that of PCL/BKC nanosphere formulation at 1 and 8h (p<0.05). The mean iris/ciliary body concentrations obtained with the three formulations were not significantly different at any time point with the exception of group 2 levels being higher than those of groups 1 and 3 at 1h (p<0.05). The lowest ocular tear Cy A concentrations (16-114 ng/ml) were found following the instillation of HA coated PCL/BKC nanoparticles (group 3) during the time period tested. Cy A loaded PCL/BKC and HA coated PCL/BKC nanospheres are able to achieve high levels of Cy A in the cornea that is 10-15-fold higher than that is achieved with Cy A solution in castor oil. Nanosphere formulation and HA may play an important role in delivering high levels of cyclosporine A into the cornea.

Juvenile xanthogranuloma of the corneal limbus: report of two cases and review of the literature.

PURPOSEnTo report the clinical and histopathologic findings of limbal juvenile xanthogranuloma lesions in 2 pediatric cases.nnnMETHODSnCase report and literature review.nnnRESULTSnTwo cases (a 7-month-old girl and a 7-year-old boy), both of whom developed a yellowish corneoscleral limbal mass not associated with other ocular or systemic findings, were evaluated. Both cases underwent simple excision of the lesion followed by local steroid treatment. Histopathologic examination in both cases revealed foamy histiocytes within an inflammatory infiltrate. One of the lesions also harbored multinucleate giant cells. Immunohistochemical staining was positive for CD68 and negative for S-100 and CD1a in both cases.nnnCONCLUSIONSnJuvenile xanthogranuloma may rarely present with an isolated lesion occurring only at the corneoscleral limbus. The diagnosis in the early stages of this disorder may be established with immunophenotyping and characteristic histopathologic features even without the presence of the multinucleate giant cells.Objectives:To evaluate the preparedness for phase 2/IIb/III microbicide trials at 4 clinical trial sites: Durban and Hlabisa (South Africa), Lusaka (Zambia), and Moshi (Tanzania). Design:A prospective cohort study was undertaken to assess site suitability for microbicide efficacy studies. Study objectives included assessing sites ability to recruit and retain high-risk women with the appropriate HIV incidence rates needed to conduct microbicide efficacy studies. Methods:Nine hundred fifty-eight consenting women were enrolled and followed for up to 1 year. Demographic, behavioral, laboratory, and clinical data were collected to determine the incidence rates of HIV, sexually transmitted infections, and pregnancy. Results:Accrual was completed in 6.3, 6.7, 7.1, and 8.3 months in Durban, Hlabisa, Moshi, and Lusaka, respectively. The highest month 12 participant retention rate was recorded in Durban (97%), followed by Hlabisa (94%), Moshi (86%), and Lusaka (93%). Mean overall age of enrolled participants was 28.6 years (ranging from 27.0 to 32.2 years) across sites. Despite condom counseling, rates of condom use were slightly lower at study end. Pregnancy incidence in the study as a whole was 20.2 per 100 women-years (wy). Overall HIV prevalence was 32.5%, and overall HIV incidence was 3.8 per 100 wy (95% confidence interval [CI]: 2.6 to 5.2). HIV incidence per site was 5.3 per 100 wy in Durban (95% CI: 2.7 to 9.2), 6.2 per 100 wy in Hlabisa (95% CI: 3.4 to 10.5); 2.6 per 100 wy in Lusaka (95% CI: 1.0 to 5.8), and 1.4 per 100 wy in Moshi (95% CI: 0.3 to 4.0). Conclusions:Preparatory studies provide accurate local estimates of HIV incidence, recruitment and retention rates, and behavioral characteristics of targeted populations for large-scale clinical trials. Determining these factors allows for better preparation for design, sample size, and appropriate population for future selection of trial sites. Because of the lower than expected HIV incidence observed at the Moshi site, only the South African and Zambian sites were selected for the phase 2/IIb trial.

In vivo confocal microscopy for the evaluation of corneal microstructure in keratoconus.

Purpose: To evaluate the corneal microstructure in keratoconus with in vivo confocal microscopy (IVCM). Methods: Unscarred corneas of 68 patients with keratoconus and 22 controls were evaluated with slit lamp examination, corneal topography, and IVCM (Confoscan 3.0, Vigonza, Italy). One eye was randomly chosen for analysis. Keratocyte, endothelial cell and basal epithelial densities, sub-basal and stromal nerve structure, and severity of stromal haze were evaluated. Results: Compared with corneas of control subjects, patients with keratoconus had a significantly lower anterior stromal keratocyte density (1279 ± 197 cells/mm2 vs. 1132 ± 178 cells/mm2, p = 0.002), lower midstromal keratocyte density (904 ± 213 cells/mm2 vs. 770 ± 120 cells/mm2, p < 0.001), lower posterior stromal keratocyte density (935 ± 113 cells/mm2 vs. 725 ± 113 cells/mm2, p < 0.001), lower endothelial cell density (2924 ± 300 cells/mm2 vs. 2719 ± 279 cells/mm2, p = 0.004), lower basal epithelial cell density (5987 ± 699 cells/mm2 vs. 4365 ± 537 cells/mm2, p < 0.001), lower sub-basal long nerve density (32.0 ± 6.5 nerves/mm2 vs. 19.6 ± 6.5 nerves/mm2, p < 0.001), thicker sub-basal (3.2 ± 0.4 μm vs. 3.7 ± 1.1 μm, p = 0.01) and stromal nerves (5.0 ± 1.2 μm vs. 8.0 ± 2.9 μm, p < 0.001), and higher proportion of corneas with haze (40.9% vs. 92.6%, p < 0.001). A history of contact lens use (n = 12) was not associated with lower keratocyte, endothelial cell, or basal epithelial cell counts. Conclusions: Corneal microstructure is abnormal in patients with keratoconus. Keratocyte and endothelial cell loss appears to be present in keratoconic corneas.

Delayed tear clearance in patients with conjunctivochalasis is associated with punctal occlusion.

Purpose: To evaluate the impact of punctal occlusion on ocular tear clearance and occurrence of epiphora in patients with conjunctivochalasis (CCh). Methods: Seventy-five eyes with the diagnosis of CCh were included in the study. CCh was graded on the basis of the extent of inferior lid margin involvement as follows: 1 = one location, 2 = 2 locations, and 3 = whole lid. Patients within the 3 groups were also subdivided on the basis of the presence of punctal occlusion. The presence of epiphora, occlusion of the inferior punctum, and fluorescein clearance test (FCT) results were recorded for every patient. Results: Of the 75 patients, 56 (75%) had epiphora, 47 (63%) had punctal occlusion, and 54 (72%) had delayed FCT. Twenty-two patients had grade 1 CCh, 43 had grade 2 CCh, and 10 had grade 3 CCh. Epiphora was present in 10 (45%) patients with grade 1 CCh, 38 (88%) patients with grade 2 CCh, and 8 (80%) patients with grade 3 CCh. Punctal occlusion and epiphora were observed more frequently in patients with grades 2 and 3 CCh compared with those with grade 1 CCh (Pearson χ2 test, P < 0.001). There was a strong correlation between delayed FCT and punctal occlusion (Spearman rank correlation analysis, r = 0.808, P < 0.001). Punctal occlusion was also correlated with the presence of epiphora (Spearman rank correlation analysis, r = 0.691, P < 0.001). Conclusions: A significant proportion of patients with CCh are symptomatic beginning with early stages of CCh. There seem to be no significant differences in any of the clinical parameters between patients with grade 2 and grade 3 CCh. Punctal occlusion seems to play an important role in the impairment of ocular tear clearance and the occurrence of epiphora.

Photochemical keratodesmos as an adjunct to sutures for bonding penetrating keratoplasty corneal incisions

Purpose: To evaluate the benefit of photochemical keratodesmos (PKD) in acute wound closure of penetrating keratoplasty (PKP) corneal incisions in vivo. Setting: Massachusetts General Hospital and Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA. Methods: Penetrating keratoplasty incisions were performed in both eyes of 6 New Zealand white rabbits, followed by application of 1.5 mM rose bengal dye at the wound edges. The incision in 1 eye of each rabbit was irradiated with neodymium:YAG laser light at 532 nm and fluence of 40 J/cm2; the contralateral control eye was untreated. Intraocular pressure at which fluid leaked at the edges (IOPL) was determined immediately after surgery. Results: The mean IOPL was 410 mm Hg ± 70 (SD) in the PKD‐treated eyes and 250 ± 150 mm Hg in the unirradiated eyes. The difference was statistically significant by paired t test (P<.05). Conclusions: Photochemical keratodesmos may be a useful adjunct to sutures for approximating PKP corneal incisions in the immediate postoperative period. This process does not induce high temperature, and thus denaturation can be avoided and structural integrity restored.

Elevated tear interleukin-6 and interleukin-8 levels in patients with conjunctivochalasis.

Purpose: To determine the interleukin (IL)-6 and IL-8 levels in the tear samples of patients with conjunctivochalasis (CCh) and to correlate the severity of symptoms with tear IL levels. Methods: Fifty-one eyes at different stages of CCh and 10 eyes of healthy controls were recruited for this prospective study undertaken at a single university-based hospital. CCh was graded based on the extent of inferior lid margin involvement as follows: 1 = single (temporal) location, 2 = 2 locations, and 3 = whole lid. The presence of punctal occlusion and fluorescein clearance patterns were recorded. Enzyme-linked immunosorbent assay was used to determine IL levels. Severity of symptoms was assessed with the ocular surface disease index. Results: Of the 51 study patients (mean age = 63.4 ± 6.9 years), 16 had grade 1, 21 had grade 2, and 14 had grade 3 CCh. Tear IL-6 and IL-8 levels were significantly higher in patients with CCh than in controls (P ≤ 0.001). Higher IL levels were observed in grades 2 and 3 CCh than in grade 1 CCh and control eyes (P < 0.001). Patients with CCh who also had punctal occlusion and delayed fluorescein clearance results had higher tear IL levels than those who did not (P ≤ 0.001). Tear IL levels were positively correlated with the clinical severity of CCh as evaluated with the ocular surface disease index (r = 0.826, P < 0.001 for IL-6 and r = 0.726, P < 0.001 for IL-8). Conclusions: Inflammation may have a role in the pathogenesis of CCh. The clinical severity of CCh parallels the increased tear IL levels. Markers for inflammation are more pronounced in the advanced stages of this disease.

Elevated tear interleukin-6 and interleukin-8 levels associated with silicone hydrogel and conventional hydrogel contact lens wear.

Purpose: The aim of this study was to evaluate the ocular tear interleukin (IL)-6 and IL-8 concentrations within the first 6 months of contact lens (CL) wear in eyes of neophyte CL users who had been commenced on either silicone hydrogel CL (SH-CL) or conventional hydrogel CL (CH-CL). Methods: Twenty-four subjects with no history of CL wear received either SH-CL (n=12) or CH-CL (n=12) for a period of 6 months in this prospective study. Tear IL-6 and IL-8 concentrations were determined before CL wear (0 months) and at 1, 3, and 6 months after CL commencement. The sera of all the subjects were tested and graded (grades 0–6) for grass, weed, and tree pollen–specific immunoglobulin E (IgE) levels. Results: Tear IL-6 concentrations at 0, 1, 3, and 6 months for SH-CL and CH-CL users were 7.1±6.4, 10.5±8.9, 18.6±17.0, 33.1±15.0 pg/mL and 10.9±8.2, 6.4±4.0, 24.2±13.2, 34.4±17.5 pg/mL, respectively. In both groups, IL-6 levels were significantly elevated at 6 months compared with those at 0 months (P<0.001). Tear IL-8 concentrations at 0, 1, 3, and 6 months for SH-CL and CH-CL users were 107.4±56.8, 106.0±47.4, 319.5±154.8, 412.6±104.1 pg/mL and 176.4±59.7, 196.2±145.0, 410.7±121.2, 456.7±19.2 pg/mL, respectively. In both groups, tear IL-8 levels were significantly elevated at 6 months compared with those at 0 months (P<0.001). The tear IL-6 and IL-8 levels were found to be similar within the 2 groups at the 6-month time point (P>0.05). The serum grass, weed, and tree pollen–specific IgE levels were similar between groups (P>0.05) and less than 0.35 kU/L (grade 0) in 22 of 24 (91.7%) participants tested. Conclusions: The SH-CL and CH-CL wear is associated with elevation of IL-6 and IL-8 levels in the tears of healthy, nonatopic neophyte CL users.

Fluorescein enhanced confocal microscopy in vivo for the evaluation of corneal epithelium.

Background:u2002 In vivo confocal microscopy is being increasingly used to evaluate corneal disorders. This study aimed to evaluate whether topical fluorescein application prior to in vivo confocal microscopy had any effect on the imaging characteristics of the corneal epithelium.

Keratic precipitate morphology in uveitic syndromes including Behçet's disease as evaluated with in vivo confocal microscopy.

PurposeTo identify the morphologic appearance of keratic precipitates (KPs) with in vivo confocal microscopy (IVCM) in uveitic syndromes.MethodsA total of 75 eyes of 72 patients with a mean age of 38.6±15.1 years who had active intraocular inflammation and whose corneas had KP on slit-lamp examination were included in this study. IVCM (Confoscan 3.0, Vigonza, Italy) was used to image the part of the corneal endothelium in which KP were most densely deposited. KP were classified into five groups: type I (small, round), type II (stippled), type III (dendritiform), type IV (large, smooth-rounded), and type V (globular). When more than one type of KP was observed with IVCM, a distinction between the predominant and the less frequent KP was made as ‘primary’ and ‘secondary’ KP.ResultsIn 50 (66.7%) eyes more than one type of KP was imaged. The size of the KP ranged between 5 and 150u2009μm. The most frequently observed primary KP type in Behçets disease was type I (100%), in ankylosing spondylitis type II (57.1%), in Fuchs’ uveitis syndrome type III (85.7%), in granulomatous uveitis type V (42.9%), in infectious uveitis type III (66.7%), and in juvenile idiopathic arthritis associated uveitis type I (66.7%). The KP types showed a statistically significant difference between different uveitic syndromes (Fishers exact test, P<0.001).ConclusionsCertain KP types appear to be characteristic of various uveitic syndromes. IVCM may have a potential role in the diagnostic work-up of uveitic patients.