Medium-term outcomes of boston type 1 keratoprosthesis implantation in Bangkok, Thailand.

PURPOSE: The aim of this study was to investigate the medium-term outcomes after Boston type 1 keratoprosthesis surgery in patients with poor prognosis for standard keratoplasty. METHODS: A prospective study of a case series was conducted at a university-based referral center from 2006 to 2013. Forty-two eyes of 40 patients with a minimum follow-up of 4 years were recruited. The main outcome measures included best spectacle-corrected visual acuity (BSCVA), keratoprosthesis retention, and complications. RESULTS: The mean follow-up was 64.9 ± 15.2 months (range, 48-88 months). At 1 week, 90.5% had an improvement in BSCVA by ≥2 lines compared with that in preoperative BSCVA. The best-ever vision was reached by the end of 6 months. Nevertheless, 39.5% (15/38) could not maintain the improved vision. The major etiology of visual deterioration after initial gains was glaucoma (60%). The initial keratoprosthesis retention rate was 80.9%, corresponding to a failure rate of 4 per 100 eye-years or 0.04/eye-year. Autoimmune diagnosis was the independent risk factor for keratoprosthesis failure (hazard ratio, 5.68; 95% confidence interval, 1.41-22.85; P = 0.014). The common postoperative complications were glaucoma, retroprosthetic membrane, corneal melting, infectious keratitis, and endophthalmitis. CONCLUSIONS: Boston type 1 keratoprosthesis is an alternative for patients who are not candidates for corneal transplants. However, there was a trend toward visual loss over time most commonly because of progressive glaucoma. Therefore, appropriate patient selection, lifelong follow-up, and early aggressive treatment of complications are recommended.

Effects of sodium hyaluronate on wavefront aberrations in dry eye patients.

PURPOSE: To investigate the effects of a single instillation of hypotonic 0.18% sodium hyaluronate artificial tears on wavefront aberrations in dry eye patients. METHODS: Fifty patients with dry eye were recruited into this single-center, prospective, double-masked, randomized controlled trial. Patients were randomly assigned to receive one drop of preservative-free, hypotonic 0.18% sodium hyaluronate (treatment) in one eye and one drop of sterile 0.9% sodium chloride solution (control) in the other eye. Ocular aberrations evaluated by a Hartmann-Shack aberrometer and severity of dry eye symptoms graded by a questionnaire (at baseline, 1, 10, 30, 60, and 120 minutes after instillation) were the main outcome measures. RESULTS: After a single instillation of one drop of the allocated eye drops, there were no statistically significant differences between the treatment and control groups in total higher-order aberrations, coma, and spherical aberrations during the study period (p = 0.40, 0.57, and 0.16, respectively). Although a statistically significant (p = 0.04) decrease from baseline in spherical aberrations was noted in the treatment group at 1 minute following instillation, it gradually increased back to baseline values at later time points. A statistically significant diminishment of dry eye symptoms compared with the placebo was reported at all time points by the treatment group (p < 0.001). CONCLUSIONS: A single instillation of hypotonic 0.18% sodium hyaluronate eye drops is safe and effective in alleviating subjective dry eye symptoms; however, it does not appear to affect higher-order aberrations in moderate to severe dry eye patients.

Progressive keratolysis with pseudopterygium associated with erythema elevatum diutinum.

OBJECTIVE: To report a patient with a rare case of progressive keratolysis with pseudopterygium associated with erythema elevatum diutinum (EED). DESIGN: Interventional case report and literature review. PARTICIPANT: One patient with ocular presentation of EED was identified. METHODS: A 64-year-old woman presented with recurrent pterygium and painful corneal thinning with impending perforation of the left eye. Examination revealed intensely inflamed pseudopterygium, paracentral and peripheral corneal ulcerations, and descemetocele with a pinpoint leakage. MAIN OUTCOME MEASURES: Clinical course and laboratory and histopathologic findings. RESULTS: Disseminated skin lesions developed during hospital admission. Examination revealed multiple, well-demarcated, discrete, red to violaceous, firm nodules and plaques on the knuckles and dorsum of the hands, and the extensor surface of the forearms, elbows, knees, right ankle, and buttocks. A skin biopsy of the recent lesions showed a dense and diffuse inflammatory cell infiltration, predominantly neutrophilic infiltrates and nuclear dust (leukocytoclasis), located around small blood vessels in the dermis, consistent with the diagnosis of EED. The diagnosis of progressive keratolysis with pseudopterygium associated with EED was made. Spontaneous, rapid resolution of both cutaneous and ocular lesions occurred after dapsone therapy. CONCLUSIONS: Erythema elevatum diutinum is a rare, chronic, and recurrent disease that has both dermatologic and ocular manifestations. Peripheral ulcerative keratitis seems to be the most common ocular finding and may be the initial presenting feature of EED. Ophthalmologists should be aware of this rare entity in the differential diagnosis of ulcerative or nonulcerative peripheral keratitis.

Pythium insidiosum keratitis in contact lens wear: a case report.

PURPOSE: The purpose of this study was to report a case of contact lens-related Pythium insidiosum corneal ulcer. METHODS: The authors conducted an interventional case report. We report the clinical presentations, histopathologic findings, and treatments of a patient with P. insidiosum keratitis associated with contact lens wear. RESULTS: A 22-year-old Thai woman presented to our clinic with a nonresponsive, progressive corneal ulcer of the left eye. Slit lamp examination showed a large central ulcer measuring 5.4 x 5.2 mm with underlying dense stromal infiltrates surrounded by subepithelial and superficial stromal opacity in a reticular pattern along with radial perineural-like infiltrates. Histopathologic examination revealed broad, branched, thin-walled nonparallel hyaline hyphae with rare septates consistent with P. insidiosum. The corneal culture confirmed the diagnosis. The infection recurred after multiple therapeutic penetrating keratoplasties. Enucleation was eventually performed to eradicate the infection. No definite report of contact lens-related P. insidiosum keratitis existed in the literature. CONCLUSION: Pythium keratitis may present with central ulcer and radial keratoneuritis similar to acanthamoeba keratitis. Contact lens wear can be a risk factor for this infection. Increasing awareness, early diagnosis, and intervention may improve the prognosis.

A serum- and feeder-free technique of culturing human corneal epithelial stem cells on amniotic membrane.

PURPOSE: To describe a simple technique of cultivating human corneal epithelial stem cells using an Epilife culture medium under serum- and feeder-free conditions. METHODS: Cadaveric donor limbal corneal epithelial cells were cultured on denuded amniotic membranes using an explant technique that was free of serum and feeder cells in the Epilife medium containing a growth supplement of defined composition. These cells were assessed by phase contrast microscope. The expressions of the proposed corneal epithelial stem cell markers (p63, ATP-binding cassette member 2 (ABCG2), and cytokeratin 15 and 19) and differentiation markers (cytokeratin 3, 12, connexin 43, and p75) were analyzed using reverse transcription polymerase chain reaction (RT-PCR) and immunocytochemical staining. RESULTS: Successful cultures were obtained, resulting in a monolayer to double layer cell sheets with a cobblestone-like morphology. RT-PCR and immunocytochemistry disclosed an expression of both putative limbal stem cell (LSC) markers and differentiation-associated markers in the cultured cells. Most of the cultured corneal epithelial cells that were immunopositive for putative LSC markers were smaller, more uniform, and closer to the limbal explant than cells positively stained with differentiation-associated markers. CONCLUSIONS: A serum- and feeder-free culture system using Epilife medium may grow human corneal epithelial equivalents, minimizing the risk of contamination during culture. The technique may also be useful for the clinical application of limbal stem cell culture.

Predisposing factors and etiologic diagnosis of ulcerative keratitis.

PURPOSE: To determine the predisposing factors, demographic characteristics, and etiology of ulcerative keratitis in a referral center in Bangkok, Thailand. METHODS: The medical records of admitted patients with positive-culture ulcerative keratitis were retrospectively reviewed for demographic data, predisposing factors, and microbial culture results. Predisposing factors were compared between bacterial and fungal keratitis. RESULTS: From January 2001 to December 2004, there were 127 positive-culture ulcerative keratitis cases. The most frequent microbiological diagnosis was bacterial keratitis (76 eyes, 60%), followed by fungal (48 eyes, 38%) and Acanthamoeba keratitis (3 eyes, 2%). The most common organisms isolated were Pseudomonas spp. for bacteria and Fusarium spp. for fungus. Compared with bacterial keratitis, fungal keratitis was more likely to be associated with ocular trauma (odds ratio = 11.20; 95% confidence interval, 3.62-34.66) but less likely to be associated with contact lens wear (odds ratio = 0.02; 95% confidence interval, 0.01-0.08). CONCLUSIONS: In our study, Pseudomonas and Fusarium species are the most common causes of bacterial and fungal keratitis, respectively. Fungal keratitis was more likely than bacterial keratitis to be associated with ocular trauma, whereas fungal keratitis was less likely to be associated with contact lens wear.

Prevalence of dry eye in Bangkok, Thailand.

PURPOSE: To estimate the prevalence of dry eye in the adult population of Bangkok, Thailand. METHODS: Five hundred fifty volunteers 40 years of age or more who presented to the Ramathibodi Hospital for annual eye examinations were enrolled. Interviewers administered a dry eye symptoms questionnaire. Slit-lamp examination and objective dry eye assessment consisting of tear film breakup time (TBUT), fluorescein corneal staining, Schirmer tests, and meibomian gland evaluation were performed. Outcome measures included frequency of symptoms and positive dry eye tests. RESULTS: Thirty-four percent reported significant symptoms, which were defined as having one or more symptoms often or all of the time (95% confidence interval, 28.1-40.6). Approximately one half had meibomian gland disease (MGD) or pingueculum/pterygium (46.2 and 53.8%, respectively). Individuals with significant symptoms tended to be women (83.4%, P = 0.024), had MGD (63.6%, P = 0.006), had current artificial tear use (33.2%, P = 0.024), and had positive TBUT (80.7%, P = 0.000) and fluorescein staining (16.6%, P = 0.013.) The presence of pingueculum/pterygium and MGD were significantly associated with positive dry eye tests. CONCLUSION: This is the first report of prevalence of dry eye inclusive of signs and symptoms in an elderly Thai population. The prevalence of disease diagnosed on the basis of symptoms and dry eye tests was approximately 2 to 3 times higher than reported in whites. Women were more likely to report symptoms. Positive associations with dry eye tests were found in subjects with pingueculum/pterygium and MGD.

Anterior vitreous tapping to manage positive vitreous pressure during triple procedures.

PURPOSE: To describe the technique and outcome of pars plana vitreous aspiration during penetrating keratoplasty (PK) combined with cataract extraction (CE) and intraocular lens (IOL) implantation (triple procedure) to prevent positive vitreous pressure and its associated complications. DESIGN: Nonrandomized prospective noncomparative interventional case series. PARTICIPANTS: Sixty-five patients who underwent triple procedures between June 2001 and September 2003. METHODS: Triple procedures performed on all 65 patients consisted of PK, extracapsular CE, and IOL implantation with standard techniques. After nonpenetrating trephination, anterior vitreous tapping was performed with a 23-gauge needle on a 5-ml syringe over the pars plana 3.5 mm posterior to the limbus in the superotemporal quadrant. MAIN OUTCOME MEASURES: Preoperative best-corrected visual acuity (BCVA), volume of aspirated liquefied vitreous, intraoperative and postoperative complications, and postoperative BCVA at 3 and 6 months. RESULTS: Corneal scarring with cataract was the most common indication for surgery. Preoperative BCVA ranged from 20/160 to light perception. Aspirated vitreous volume varied from 0.3 to 1.5 ml, averaging 1.0 ml. No case had evidence of positive vitreous pressure during surgery. The mean follow-up period was 9.6+/-2.6 months (range, 6-24). Postoperative complications consisted of graft rejection in 4 cases (6.2%), primary graft failure in 3 (4.6%), and secondary glaucoma in 1 (1.5%). Of the patients, 70.8% had a postoperative BCVA of > or =20/160 at 6 months. Vitreous hemorrhage, retinal tearing, and detachment were not observed. CONCLUSIONS: Pars plana anterior vitreous tapping is a safe adjunct for triple procedures to prevent positive vitreous pressure and its associated complications.

Laser in situ keratomileusis for high myopia using a small ablation zone and large aspheric transition zone.

PURPOSE: To evaluate the efficacy and predictability of laser in situ keratomileusis (LASIK) using the Nidek NAVEX system with a small ablation (optical, OZ) zone and a large aspheric transition zone (OATz). METHODS: We report a prospective nonrandomized study of LASIK for high myopia using a small ablation in 23 eyes of 18 patients. The optical zone was between 3 and 3.8 mm and transition zone (TZ) was between 7 and 7.8 mm. Preoperative examination included best-spectacle corrected visual acuity (BSCVA), refraction, and corneal topography. All eyes were measured by the Nidek OPD-Scan and data were imported to FinalFit software. Aspheric profile (OATz) numbers 5 to 7 were used. BSCVA, uncorrected spectacle visual acuity (UCVA), refraction, and subjective evaluation of glare and night vision by questionnaire were recorded after surgery. RESULTS: At baseline, mean spherical equivalent refraction was -7.03 +/- 2.39 D (range -5.50 to -15.50 D). Postoperative UCVA was better than 20/25 in 95.65% of eyes 3 months after LASIK. Postoperative refraction was within +/- 0.50 D of emmetropia in 91.3% of eyes and within +/- 1.00 D in all eyes. No eye lost lines of BSCVA; 52.17% of eyes gained 1 line and 13.04% of eyes gained 2 lines. No patient reported significant glare or night vision problems on subjective questionnaire. CONCLUSION: LASIK with a small ablation (optical) zone and high aspheric transition zone using the Nidek NAVEX system was effective, predictable, and relatively safe for correction of high myopia.

Comparison of conventional and OATz ablation profiles for laser in situ keratomileusis to correct myopia up to -10.00 diopters.

PURPOSE: To compare results of laser in situ keratomileusis (LASIK) using two different ablation profiles for correction of myopia between -0.50 and -10.00 D with the Nidek NAVEX system. METHODS: In a prospective nonrandomized study, 249 myopic eyes (151 patients) had LASIK for correction of myopia. The Nidek MK-2000 micro-keratome and the Nidek NAVEX excimer laser system were used in all eyes. Conventional LASIK was performed in 112 eyes of 64 patients with a 6.0-mm ablation zone and 7.5-mm transition zone (conventional group). LASIK with the Nidek OATz ablation profile was performed in 137 eyes of 87 patients, with variable ablation and transition zones (OATz group). Mean baseline manifest refraction was -4.11 +/- 1.83 D in the conventional group and -5.45 +/- 2.27 D in the OATz group. Baseline best spectacle- corrected visual acuity was 20/20 or better in 83.9% of eyes in the conventional group and 81.0% of eyes in the OATz group. RESULTS: Mean follow-up was 3.6 months (range 3 to 8 mo). At last follow-up, manifest refraction was within +/-0.50 D of emmetropia in 86% of eyes (within +/-1.00 D in 99.1%) in the conventional group and 94.2% of eyes (within +/-1.00 D in 100%) in the OATz group. Uncorrected visual acuity was 20/40 or better in all eyes. No eyes in either group lost 2 or more lines of BSCVA. CONCLUSIONS: The Nidek NAVEX system was safe and predictable in correcting myopia up to -10.00 D with the OATz ablation profile. OATz LASIK was similar to conventional LASIK in both refractive and visual outcomes.

Comparison of conventional versus wavefront-guided laser in situ keratomileusis in the same patient.

PURPOSE: To verify whether there is any difference in visual outcome, including higher order aberrations, after performing laser in situ keratomileusis (LASIK) with conventional ablation and wavefront-guided ablation in myopic eyes of the same patient. METHODS: This was a prospective randomized study of 20 myopic eyes (10 patients) who had LASIK using the Nidek NAVEX excimer laser system. Wavefront-guided customized ablation was used in the first eye of the patient (study group) and the other eye of the same patient was operated with conventional ablation (control group). Mean refractive error was similar between left and right eyes of the same patient. Preoperative examination included higher order aberration by Nidek OPD-Scan. Uncorrected and best spectacle-corrected visual acuity and higher order aberrations were recorded postoperatively. RESULTS: Preoperative and postoperative best spectacle-corrected visual acuity was better than 20/40 (100%) after LASIK in both the conventional ablation and wavefront-guided customized ablation groups. Postoperative refraction was within +/- 0.50 D of emmetropia: 90% in the conventional group and 100% in the wavefront-guided group. No statistically significant difference in postoperative higher order aberrations was found between groups. CONCLUSION: Postoperative visual outcome with both conventional LASIK and wavefront-guided customized ablation was not significantly different. Higher order aberrations did not significantly increase postoperatively in either group.

Comparison of wavefront-guided customized ablation vs. conventional ablation in laser in situ keratomileusis.

PURPOSE: To compare visual outcome after applying wavefront-guided customized ablation with conventional ablation in laser in situ keratomileusis (LASIK) patients. METHODS: We performed a prospective, randomized controlled study that included 22 eyes of 11 patients who were treated with LASIK using the Nidek EC-5000 excimer laser system. We applied wavefront-guided customized ablation (study group) in the first eye of each patient. The conventional ablation (control group) was performed in the other eye of the same patient. Best spectacle-corrected visual acuity (BSCVA), spherical equivalent refraction, and high-order aberrations were evaluated preoperatively and at 1 month. High-order aberrations were measured using the Nidek OPD-Scan. RESULTS: Preoperative and 1-month postoperative BSCVA were better than 20/40 (100%) after LASIK with both conventional ablation (control) and wavefront-guided customized ablation. Preoperatively, mean high-order aberrations in the control group were 0.572 and in the study group, 0.428 (Zernike coefficient unit). One-month after LASIK, mean high-order aberrations in the control group were 0.496 and in the study group, 0.476 (Zernike coefficient unit). We found no statistically significant difference between preoperative and 1-month postoperative high-order aberrations in either group. CONCLUSION: LASIK with both conventional ablation and wavefront-guided customized ablation resulted in the same BSCVA 1 month after LASIK. Preoperative and 1-month postoperative high-order aberrations were not statistically different following LASIK between ablation types.