Baris Sonmez

Posterior polymorphous corneal dystrophy is associated with TCF8 gene mutations and abdominal hernia.

Mutations in the two‐handed zinc‐finger homeodomain transcription factor gene (TCF8) have been associated with posterior polymorphous corneal dystrophy (PPCD) and extraocular developmental abnormalities. We performed screening of TCF8 in 32 affected, unrelated probands, affected and unaffected family members of probands identified with a TCF8 mutation, and in 100 control individuals. Eight different pathogenic mutations were identified in eight probands: four frameshift (c.953_954insA, c.1506dupA, c.1592delA, and c.3012_3013delAG); three nonsense (Gln12X, Gln214X, Arg325X); and one missense (Met1Arg). Screening of TCF8 in affected and unaffected family members in six families demonstrated that each identified mutation segregated with the disease phenotype in each family; two probands did not have additional family members available for analysis. None of the eight TCF8 mutations was identified in 200 control chromosomes. The prevalence of hernias of the abdominal region in affected individuals with PPCD associated with TCF8 mutations was significantly higher than the prevalence in both individuals with PPCD not associated with a TCF8 mutation and in unaffected individuals. Therefore, PPCD is associated with TCF8 mutations in one quarter of affected families in this study, or about one third of all PPCD families that have been screened thus far. In these families, the presence of apparently causative TCF8 mutations is associated with abdominal and inguinal hernias.

Amniotic membrane transplantation with anterior stromal micropuncture for treatment of painful bullous keratopathy in eyes with poor visual potential.

Purpose: To report the use of anterior stromal micropuncture and amniotic membrane transplantation in the management of painful bullous keratopathy in patients with poor visual potential. Methods: Interventional case series. A retrospective review was performed to identify all patients who were treated by one of us (A.J.A.) between January 1, 2003, and June 30, 2005. Results: Five eyes of 5 patients were identified. Conjunctival scarring secondary to glaucoma and retinal surgeries prevented mobilization of the conjunctiva in each of the patients identified. Each eye showed an intact, smooth corneal epithelial surface 1 month after the procedure, and no patients developed recurrent bullae formation during the follow-up period (average follow-up, 21 months; range, 11-34 months). Conclusions: Anterior stromal micropuncture and amniotic membrane transplantation is an effective technique for the management of bullous keratopathy in patients with poor visual potential. The success rate of this combined procedure may exceed that of either procedure performed alone.

Keratoconus is not associated with mutations in COL8A1 and COL8A2.

Purpose: To evaluate the suggested role of the COL8A1 and COL8A2 genes in the pathogenesis of the corneal ectatic disorders keratoconus and keratoglobus through mutation screening in affected patients. Methods: DNA extraction, polymerase chain reaction amplification, and sequencing of COL8A1 and COL8A2 were performed in 50 unrelated keratoconus and 2 unrelated keratoglobus patients. Results: No sequence variations were identified in COL8A1 and COL8A2 in the 2 patients with keratoglobus. Screening of COL8A1 in keratoconus patients revealed a previously identified single nucleotide polymorphism (SNP; c.1850C>T; Pro535Pro), in 1 patient. Screening of COL8A2 in keratoconus patients revealed 7 previously described SNPs: c.14G>A (Gly3Arg); c.112G>A (Ala35Ala); c.1012C>G (Leu335Leu); c.1308G>A (Arg434His); c.1492G>A (Gly495Gly); c.1512C>T (Thr502Met); and c.1765C>T (Pro586Pro). Four novel sequence variants were also identified, each in 1 affected patient: c.38_40dupCTG (Leu11dup), also identified in an unaffected relative of the affected proband, c.667G>A (Gly220Gly), c.1588G>A (Pro527Pro), and c.2026C>T (Val673Val). None of the 3 novel synonymous substitutions identified in COL8A2 was predicted to produce a splice acceptor site. Conclusions: The absence of pathogenic mutations in COL8A1 and COL8A2 in patients with keratoconus indicates that other genetic factors are involved in the pathogenesis of this corneal ectatic disorder.

A Novel Variant of Combined Granular-Lattice Corneal Dystrophy Associated With the Met619Lys Mutation in the TGFBI Gene

OBJECTIVE To report a novel mutation in TGFBI (GenBank NM_000358), p.Met619Lys, associated with a variant of combined granular-lattice corneal dystrophy. METHODS Slitlamp examination and DNA collection from the proband and affected and unaffected relatives. All 17 exons of TGFBI were amplified and sequenced in the proband. Exon 14 was amplified and sequenced in the probands family members and in 100 controls. Histopathologic examination of the excised corneal buttons from the proband and 3 family members was also performed. RESULTS Affected individuals demonstrated an age-dependent phenotype, with the progression from central subepithelial needlelike deposits in younger individuals to polymorphic anterior stromal opacities in older family members. Screening of TGFBI in the proband demonstrated a novel mutation, p.Met619Lys, which was also present in all affected family members. Histopathologic examination revealed stromal deposits that stained with the Congo red and Masson trichrome stains as well as an antibody to the protein product of TGFBI. CONCLUSIONS We present a unique corneal dystrophy phenotype associated with the novel p.Met619Lys mutation in TGFBI. Clinical Relevance The atypical and variable phenotype and the demonstration of both hyaline and amyloid stromal deposits indicate that neither clinical nor histopathologic features may be relied on to accurately diagnose and classify the corneal dystrophies.

Comparison of central corneal thickness measurements by Galilei Dual-Scheimpflug analyzer® and ultrasound pachymeter in myopic eyes.

BACKGROUND AND OBJECTIVE To compare the central corneal thickness (CCT) measurements by Galilei Dual-Scheimpflug analyzer (GSA) (Ziemer Group, Port, Switzerland) and ultrasound pachymeter (UP) in myopic eyes. PATIENTS AND METHODS In this prospective study, CCT of 161 myopic eyes of 81 refractive surgery candidates (35 female, 46 male; mean age: 23.18 ± 4.08 years) were measured by GSA and UP consecutively. The data were analyzed statistically by paired t test, Bland-Altman plot, and Pearson correlation test to assess the agreement of the measurements. RESULTS The mean CCTs obtained by GSA and UP were 559.85 ± 30.87 and 560.41 ± 34.45 μm, respectively. No significant difference was found between the measurements (P = .684) and regression analysis showed a high correlation between the measurements obtained with both devices (r = 0.86; P < .001). A strong agreement between the two methods was also found by Bland-Altman plot. CONCLUSION In myopic eyes, the CCT measurements of GSA and UP are similar and highly correlated. Because of high agreement between these devices, the GSA is a non-contact method that may be an alternative to UP for measurement of CCT.

Fibrin glue-assisted sutureless limbal stem cell transplantation surgery for the treatment of severe ocular chemical injury.

Purpose: To report the use of fibrin tissue glue in securing the keratolimbal allograft (KLAL) and living-related conjunctival limbal allograft to the ocular surface in patients with severe ocular chemical injury. Design: A retrospective review of interventional case series. Methods: Conjunctival limbal allografts were harvested from the first-degree living-related relatives under topical anesthesia and fixated to the superior and inferior limbal quadrants in the recipient eye. The KLALs were fixated mainly to the nasal and temporal limbus with the help of fibrin tissue glue after being cut into 2 crescents and manually dissected to near one-third thicknesses in a lamellar fashion. Results: Five eyes of 4 patients were included in the study. The sources of the chemical injuries were: CaOH2 (3 eyes), NaOH (1 eye), and mitomycin C (1 eye). The limbal stem cell deficiency was 360 degrees in 4 eyes and 300 degrees in 1 eye. Corneas were covered with conjunctiva or fibrovascular tissue adjacent to the areas with limbal stem cell deficiency. The fibrin tissue glue was effective in securing both the keratolimbal and the conjunctivolimbal grafts at the surgery. Postoperatively, the corneal epithelium healed within 1 week in all of the eyes. Neither graft dislocation nor graft rejection occurred after a mean of 18.2 months of follow-up. Conclusions: The use of fibrin glue to fixate the KLAL and the living-related conjunctival limbal allograft in patients with severe chemical trauma is practical and effective. This technique may also be beneficial in terms of decreasing the risk of rejection in this patient group.

Bilateral simultaneous primary orbital lymphoma presenting with unilateral enophthalmos.

A 73-year-old woman was examined for palpable orbital masses behind the right upper eyelid and left lower eyelid leading to entropion. Hertel exophthalmometry readings were 6.0 mm in the right eye and 11.0 mm in the left eye with a base of 102 mm. MRI revealed bilateral hypointense orbital soft-tissue masses. Pathologic evaluation of incisional biopsy specimens revealed malignant tissue composed of diffuse, mitotically active, atypical large lymphoid cells positive for CD-20 with immunohistochemical staining, confirming the diagnosis of malignant diffuse large B-cell lymphoma. Systemic survey was negative for extraorbital involvement. After R-CHOP chemotherapy (Rituximab 375 mg/m2 intravenously, Cyclophosphamide 750 mg/m2 intravenously, Doxorubicin 50 mg/m2 intravenously, Vincristine 1.4 mg/m2 intravenously, Prednisolone 100 mg orally), Hertel measurements were 9.0 mm in the right eye and 11.0 mm in the left eye. The mass lesions were totally regressed in follow-up MRI. Although rare, non-Hodgkin lymphoma may present bilaterally as primary orbital lesions and can unexpectedly cause enophthalmos instead of proptosis.

Autosomal dominant cornea plana is not associated with pathogenic mutations in DCN, DSPG3, FOXC1, KERA, LUM, or PITX2.

Purpose: To determine the genetic basis of autosomal dominant cornea plana (CNA1) through the performance of a genome-wide linkage analysis and screening of the decorin (DCN), dermatan sulfate proteoglycan 3 (DSPG3), forkhead box C1 (FOXC1), keratocan (KERA), lumican (LUM,) and paired-like homeodomain transcription factor 2 (PITX2) genes in members of an affected multigenerational family. Methods: Cycloplegic refraction, slit lamp biomicroscopy, corneal pachymetry, and corneal topography were performed to determine each patients affected status. DNA was obtained from affected and unaffected subjects for the performance of a genome-wide linkage analysis as well as PCR amplification and sequencing of DCN, DSPG3, FOXC1, KERA, LUM, and PITX2. Results: Five affected and three unaffected individuals were examined and provided a peripheral blood sample for DNA isolation. All affected individuals demonstrated an average corneal dioptric power less than 39 D, as well as one or more of the following anomalies: high hyperopia, strabismus, microcornea, posterior embryotoxon, iridocorneal adhesions, iris atrophy, and pupillary irregularities. A genome-wide linkage analysis did not indicate or exclude linkage to the region on chromosome 12 to which CNA1 has been previously mapped, and did not provide a single or multipoint LOD score greater than 2.0 for any of the 400 microsatellite markers. Screening of DCN, DSPG3, FOXC1, KERA, LUM, and PITX2 revealed 12 previously described single nucleotide polymorphisms, 2 previously described duplications, and 1 previously described insertion. None of the mutations previously associated with autosomal recessive cornea plana (CNA2) were identified. Seven novel sequence variants were described, including 5 single nucleotide substitutions, 1 insertion and 1 deletion. None of the identified sequence variants demonstrated complete segregation with the affected phenotype in the pedigree. Conclusion: Although missense and nonsense mutations in KERA are associated with CNA2, we did not identify any of the previously described mutations or novel mutations that segregated with the disease phenotype in a family with CNA1. In addition, no pathogenic sequence variations were found in DCN, DSPG3, LUM, PITX2 and FOXC1, which have also been implicated in corneal and anterior segment dysgenesis.

An Unusual Presentation of Macular Corneal Dystrophy Associated with Uniparental Isodisomy and a Novel Leu173Pro Mutation

Purpose: To report an unusual phenotype of macular corneal dystrophy (MCDC1) associated with a novel CHST6 mutation transmitted via maternal isodisomy. Methods: Slit lamp examination of the patient and his parents was performed. DNA was collected from each individual for amplification and sequencing of the CHST6 coding region, as well as exons 4 and 12 of TGFBI. Serum antigenic keratan sulfate (AgKS) levels were measured for confirmation of the diagnosis and subtyping of MCDC1. Quantitative real-time PCR (qPCR) was performed to differentiate between homozygous and hemizygous sequence variants. Genotyping at 12 single nucleotide polymorphisms (SNPs) within and surrounding CHST6 was performed to determine the pattern of inheritance of mutations identified in CHST6. Results: Examination of the proband revealed bilateral, discrete, axially distributed, gray-white deposits at the level of Bowmans layer, with diffuse fine corneal stromal haze. Screening of TGFBI exons 4 and 12 in the proband did not reveal any allelic variants. However, screening of CHST6 in the proband demonstrated a novel homozygous missense mutation involving a highly conserved amino acid (c.518T > C; Leu173Pro) and undetectable serum AgKS levels in the proband confirmed the diagnosis of type I MCDC1. Quantitative PCR confirmed that both copies of CHST6 were present in the patient, excluding the possibility that the mutation was present in the hemizygous state. The results of genotyping were consistent with maternal isodisomy, as the patient was homozygous for an allele possessed by his mother at each SNP, two of which were informative and demonstrated nonpaternal inheritance. Conclusion: A phenotypically unusual variant of MCDC1 was found to be associated with the novel Leu173Pro mutation in CHST6, transmitted via uniparental isodisomy, a previously unreported pattern of inheritance in the corneal dystrophies.

Orbital Drainage of Different Sizes of Colloids in Rabbits: A Dynamic Scintigraphic Study

PURPOSE To investigate the drainage patterns of radiolabeled colloids of different sizes injected into the orbital cavity in an animal model. METHODS Twenty-one orbits of 11 rabbits were included in the study. In group 1, human serum macroaggregates with particle sizes of 10 to 100 microm, labeled with 10 mL of 1480 MBq (40 mCi) technetium pertechnetate Tc 99m (99mTc), were used. In group 2, human serum albumin colloidal particles with particle sizes of 50 to 80 nm, labeled with 5 mL of 740 MBq (20 mCi) 99mTc, were used. In group 3, colloidal tin with particle sizes of 300 to 600 nm, labeled with 9 mL of 1665 MBq (45 mCi) 99mTc, were used. The dynamic acquisition of liver for 10 minutes (120 frames for 5 seconds) in a 128 x 128 matrix was acquired immediately after intraorbital injection and at the end of the second hour. RESULTS The liver in groups 2 and 3 and the lung in group 1 were visualized in 10 seconds or less in six, five, and four rabbits, respectively. The injected activity persisted in the orbits in varying percentages in all rabbits at the end of acquisition. CONCLUSIONS Intraorbital injections have a great potential for systemic absorption and should not be considered as local pharmaceutical administration.