Yu-Chih Hou

Overnight orthokeratology-associated microbial keratitis.

Purpose: This study was designed to report the clinical aspects, microbiologic findings, and treatment outcomes of overnight orthokeratology-associated microbial keratitis. Methods: Medical records of patients with overnight orthokeratology-associated microbial keratitis at National Taiwan University Hospital from August 2000 to October 2001were reviewed. The clinical and microbiologic characteristics and treatment outcomes were investigated. Results: Nine patients (in total 10 eyes) from aged 8 to 17 (mean, 12.3 ± 2.9) years were included in this study. Eight patients had a unilateral infection and one had a bilateral infection. The initial best corrected visual acuities ranged from hand motion to 20/20. The lesions were located at the central cornea in nine eyes (90%). Smears and cultures from corneal scrapings were obtained from all patients. Four eyes were culture-positive, which included nonfermentative Gram-negative bacillus, Pseudomonas aeruginosa and Acanthamoeba. Positive smears from another two eyes revealed Gram-negative bacilli and double-walled cyst. All patients were cured using antimicrobial medications with complete re-epithelization and disappearance of corneal infiltrates. Four eyes had a final best corrected visual acuity of 20/30 or worse after a mean follow-up of 9.4 months, including one eye that had visual acuity of hand motion only. Complications included corneal opacity in all eyes, glaucoma in one eye, and cataract in one eye. Conclusions: Overnight orthokeratology is an important risk factor of microbial keratitis, especially in school children. Acanthamoeba and Gram-negative bacilli, especially Pseudomonas aeruginosa, are the most common pathogens in our series. The risk of microbial keratitis after overnight orthokeratology should not be overlooked.

Subconjunctival injection of bevacizumab in the treatment of corneal neovascularization associated with lipid deposition.

Purpose: To determine the effects on corneal neovascularization (NV) and lipid deposition after subconjunctival injection of bevacizumab in patients who had NV associated with lipid keratopathy. Methods: A case interventional study enrolled 18 patients (18 eyes) with lipid keratopathy. We gave monthly subconjunctival injections of bevacizumab from 3 to 10 times during the follow-up period according to the clinical response. We evaluated the centricity, extent, and percentage of involved corneal surface (PICS) of the corneal NV; the density and PICS of the corneal lipid deposition; and best-corrected visual acuity before and after treatment. We analyzed the treatment effects using Wilcoxon and Student t tests. Results: After the treatment, the change in best-corrected visual acuity was less than 2 lines. The extent, centricity, and PICS of the corneal NV and the density and PICS of the corneal lipid deposition decreased significantly after treatment (P = 0.014/0.002/0.001 and 0.001/<0.001, respectively). No eyes had side effects. Conclusions: The effects of subconjunctival injection of bevacizumab in treating corneal NV associated with lipid deposition were significant in some patients.

Linkage study of best's vitelliform macular dystrophy (VMD2) in a large North American family

Bests vitelliform macular dystrophy (VMD2) is an autosomal dominant retinal dystrophy for which the underlying biochemical cause is unknown. We used 11 genetic markers in the vicinity of the VMD2 gene in our study of a large North American family in which macular dystrophy characteristics overlap the broad definition of Bests disease. Significant evidence for linkage was found for markers D11S956 (Z = 5.88, theta = 0.04) and FCER1B (Z = 4.31, theta = 0.00). Recombination events localized the disease gene to the 5-cM interval D11S956-UGB, a genetic inclusion interval that substantially overlaps the VMD2 inclusion interval defined by recombinants at FCER1B and UGB observed by other research groups. The resulting exclusion of ROM1 from the genetic inclusion interval eliminates ROM1 defects as a possible cause of the disease in this family. Linkage studies of many families, including those that share most but not all features with classical Bests disease, will be needed to properly evaluate genetic heterogeneity and the range of phenotypic variation that can result from VMD2 defects.

Recurrent Corneal Perforation and Acute Calcareous Corneal Degeneration in Chronic Graft-Versus-Host Disease

Keratoconjunctivitis sicca (KCS) is a common complication of graft-versus-host disease (GVHD), and may lead to corneal epithelial defect and melting. In contrast, recurrent corneal calcareous degeneration and perforation is rare. A 46-year-old woman developed chronic GVHD after bone marrow transplantation for aplastic anemia. Severe KCS with corneal melting and calcium deposits were noted in the left eye. Penetrating keratoplasty was performed because of corneal perforation, but poor re-epithelialization and calcium deposition recurred. Lamellar keratectomy and amniotic membrane transplantation (AMT) were performed, but acute calcareous degeneration developed with subsequent recurrence of corneal perforation. After regraft, AMT and tarsorrhaphy, the corneal graft remained clear for 3 months. However, breakdown of the corneal epithelium occurred 3 weeks after spontaneous separation of tarsorrhaphy. Six months later, corneal perforation recurred again along with exacerbation of GVHD. Regraft was performed, but the patient refused tarsorrhaphy and AMT. Poor re-epithelialization persisted after regraft. Corneal melting with impending corneal perforation ensued. Further corneal surgery was refused and the patient chose to undergo evisceration. This case demonstrates that the ocular complications of GVHD may be severe enough to lead to corneal perforation and calcareous degeneration that is recalcitrant to medical and surgical treatment.

Recurrent Corneal Erosions Treated with Anterior Stromal Puncture by Neodymium: Yttrium-Aluminum-Garnet Laser

PURPOSE To evaluate the clinical outcomes in patients with recurrent corneal erosions who received anterior stromal puncture by use of neodymium:yttrium-aluminum-garnet (Nd:YAG) laser. DESIGN Retrospective, nonrandomized, consecutive case series. PARTICIPANTS From 2000 to 2005, 33 eyes of 33 patients with unilaterally recurrent macroform corneal erosions showing poor response to conservative management who were treated with Nd:YAG laser were studied. INTERVENTION Anterior corneal stromal puncture with Nd:YAG laser was performed in the loosened epithelium or epithelial defect area. The causes and frequency of corneal erosions and the spot numbers and total energy of the Nd:YAG laser were recorded. Slit-lamp biomicroscopic examination, refraction, corneal topography, and times of laser were reviewed. A questionnaire regarding the preoperative and postoperative difference in the intensity of pain and frequency of corneal erosion was provided. MAIN OUTCOME MEASURES Rate of recurrence and pain assessment by numerical rating scale. RESULTS Sixteen eyes were completely symptom free and 12 eyes had mild pain but no evidence of recurrent corneal erosion after operation. Five eyes had repeated episodes of recurrent corneal erosion. Eyes with a traumatic cause responded better to Nd:YAG laser therapy than those without. The frequency of corneal erosions and the severity of pain significantly improved in eyes with macroform and symptom-only recurrence. There was no significant change in refraction, but corneal surface regularity slightly improved after surgery. No adverse reaction was observed during follow-up. CONCLUSIONS Anterior stromal puncture by Nd:YAG laser is an effective and simple procedure to treat recurrent corneal erosion. It can ameliorate the frequency of attacks and the intensity of pain.

Conjunctival Resection Combined With Tenon Layer Excision and the Involvement of Mast Cells in Superior Limbic Keratoconjunctivitis

PURPOSE To evaluate the effectiveness of conjunctival resection combined with Tenon layer excision in treating superior limbic keratoconjunctivitis (SLK) and the involvement of mast cells in SLK. DESIGN Retrospective, interventional case series. METHODS Forty eyes of 30 SLK patients who were unresponsive to medical treatment received superior bulbar conjunctival resection, and another 20 patients who underwent cataract and retinal surgery served as a control group. The conjunctiva specimens from study and control patients were examined by hematoxylin and eosin staining and immunohistochemistry using antibodies against mast cell tryptase. RESULTS In all operated eyes, the clinical symptoms and signs, including irritation and redness and superior bulbar conjunctival hyperemia and superior tarsal conjunctival papillary hypertrophy, subsided significantly three months after the operation. Only three eyes had recurrence from the margin of conjunctival resection, and this was relieved after reoperation. Keratinized conjunctival epithelium, loss of goblet cells, and increased mast cell numbers (P<.05) were found in the SLK group. CONCLUSIONS Our cases demonstrate that superior bulbar conjunctival resection combined with Tenon layer excision is an effective treatment for SLK. The pathologic findings suggest that mast cells may play a role in the pathogenesis of SLK.

Recurrent herpetic keratouveitis following YAG laser peripheral iridotomy

Objective: To report recurrent herpetic keratouveitis following YAG laser peripheral iridotomy. Methods: Case report. Results: A 64-year-old woman with a history of dendritic keratitis underwent Nd:YAG laser peripheral iridotomy and developed geographic epithelial keratitis with stromal keratouveitis. Culture of a corneal swab grew herpes simplex virus type I. Keratouveitis subsided with acyclovir and corticosteroid therapy. Conclusions: Recurrent herpetic keratouveitis may be induced by YAG laser iridotomy.

Probable Exclusion of GLC1A as a Candidate Glaucoma Gene in a Family with Middle-age-onset Primary Open-angle Glaucoma

PURPOSE To determine whether an adult-onset variety of primary open-angle glaucoma in family UM:POAG1 is linked to the previously mapped GLC1A juvenile-onset primary open-angle glaucoma locus on chromosome 1q or whether linkage can be excluded. METHODS Microsatellite repeat markers from the 9 cM D1S196 to D1S218 interval containing the GLC1A gene were amplified by polymerase chain reaction from DNA samples collected from 11 members of one sibship in family UM:POAG1. Haplotype analysis was carried out, including calculation of the probability that the observed data would have been obtained if the underlying cause of primary open-angle glaucoma in this family were a defect in a gene located in the tested interval. Linkage analysis was carried out under an autosomal dominant model for GLC1A glaucoma. RESULTS In family UM:POAG1, primary open-angle glaucoma was diagnosed in six surviving and one deceased member of a sibship of 13 individuals during the fifth or sixth decade of life. Glaucoma in this family has a later average age at diagnosis and significantly less elevation in intraocular pressure than GLC1A glaucoma so far described. Haplotype analysis, using a population prevalence up to 0.9%, shows that it is unlikely that the reported data would have been observed if primary open-angle glaucoma in this pedigree were due to the GLC1A locus on chromosome 1q21-q31. Linkage analysis under the juvenile glaucoma autosomal dominant model allowed exclusion of linkage across the entire GLC1A genetic inclusion interval, with a maximum lod score in the interval of -3.28. CONCLUSION The most likely interpretation of these observations is that a defect in the GLC1A glaucoma gene is not responsible for adult-onset primary open-angle glaucoma in family UM:POAG1. This suggests the existence of at least two primary open-angle glaucoma genes, the previously reported GLC1A gene on chromosome 1q and another gene located elsewhere in the genome. Diagnosis of UM:POAG1 glaucoma between 42 and 57 years of age also raises questions regarding the relation of the glaucoma present in this family to the common later-age-onset form of the disease.

Intraocular pressure measurement with the noncontact tonometer through soft contact lenses.

PurposeTo assess the accuracy of measuring intraocular pressure (IOP) through a soft contact lens (SCL) with different refractive powers using a noncontact tonometer (NCT). MethodsThirty-two healthy adult volunteers free of glaucoma or corneal disease participated in this study. IOP was measured in the right eyes without SCLs and with different lens powers, from −3.0 to −12.0 D as measured by NCT. IOP of the left eyes was also measured, as an internal control. Corneal curvature was measured in both eyes using an autokeratometer. Sixteen volunteers wore one brand of SCL (group A) and the other 16 wore a different brand, with 2 different curvatures (groups B and C). Statistical data were analyzed by SPSS using the Wilcoxon signed rank test for comparison of IOP readings and multiple linear regression analysis for the relationship among power of contact lenses, corneal power, and difference in IOP measurements. ResultsThe difference in mean IOP between eyes without lenses and those with lenses was statistically significant in lens with −6.0 D and below in all 3 groups. The decrease in IOP significantly correlated with the refractive power of contact lenses in all 3 groups. The difference in IOP measurements was influenced by the mean K in group A but not in group B or C. There was no statistically significant difference in the IOP measurements in the left eyes or in the mean K between the right and left eyes. ConclusionsIOP measurement through myopic SCLs by NCT may be inaccurate and tends toward underestimation, especially in high myopic lenses. A strong relationship exists between IOP reduction and myopic lens power.

A comparison of the effect of carbomer-, cellulose- and mineral oil-based artificial tear formulations.

Purpose To compare the efficacy, safety, and local tolerance between carbomer-based artificial tears, cellulose-, and mineral oil-based artificial tears. Methods A randomized, open-label, parallel-group comparative 28-day study was designed for 67 patients who were randomized into three treatment groups. Measurements included the scoring of total subjective symptoms and objective signs, Schirmer-Jones test values, and tear break-up time (BUT) at baseline, and after 2 and 4 weeks of treatment. Safety of study treatment was also assessed. Outcomes measured at baseline and 2 and 4 weeks follow-up included the scoring of total subjective symptoms and objective signs, Schirmer-Jones test values, and tear BUT, subjective assessments, and safety. Results There were no differences regarding total scores, Schirmer-Jones test, or tear BUT at baseline among these three groups at 2 and 4 weeks. Patients in all three treatment groups experienced a significant improvement from baseline in total scores and Schirmer-Jones test values after treatment. Subjective assessment was better with carbomer-based treatment. Conclusions Each artificial tear formulation successfully relieved symptoms and signs of keratoconjunctivitis sicca. The tolerance of carbomer-based artificial tears was comparable to that of cellulose- and mineral oil-based artificial tears. (Eur J Ophthalmol 2007; 17: 151–9)