Cordelia Chan

Microsporidial keratoconjunctivitis in healthy individuals: A case series

PURPOSE To present a series of 6 cases of microsporidial keratoconjunctivitis in healthy, nonimmunocompromised individuals. DESIGN Retrospective, noncomparative case series. PARTICIPANTS Six individuals with unilateral keratoconjunctivitis. METHODS Cornea epithelial scrapings were taken and evaluated by modified trichome staining. Blood was taken for human immunodeficiency virus (HIV) enzyme-linked immunosorbent assay in all cases and for CD4 and CD8 T-lymphocyte counts in 5 cases. MAIN OUTCOME MEASURES The individuals were evaluated based on symptoms, visual acuity, slit-lamp biomicroscopy, and pathologic examination of the corneal scrapings. RESULTS All cases occurred in men whose ages ranged from 16 to 37 years. Initial symptoms included unilateral pain and redness. All experienced subsequent worsening of symptoms and blurring of vision after using topical steroids prescribed by general practitioners. Slit-lamp biomicroscopy revealed coarse, multifocal, punctate epithelial keratitis in all 6 cases, anterior stromal infiltrates in 2 cases, with accompanying conjunctivitis in all cases. Modified trichrome staining of corneal epithelial scrapes revealed pinkish to red spores characteristic of microsporidia in all cases. Results of an HIV enzyme-linked immunosorbent assay were negative in all cases, and CD4 and CD8 T-lymphocyte counts and ratios were normal in all 5 tested cases. On diagnosis, topical steroid therapy was stopped in all cases. Treatment with topical Fumidil B (bicyclohexylammonium fumagillin; Leiters Park Ave Pharmacy, San Jose, CA) together with oral albendazole was given in 3 cases, oral albendazole alone in a single case, and broad-spectrum antibiotic treatment with topical norfloxacin or chloramphenicol in two cases. Two cases had keratic precipitates with mild cellular activity in the anterior chamber and one such case was restarted subsequently on topical steroids. All six cases showed resolution of epithelial keratitis but with residual visually inconsequential subepithelial scars by the end of 1 month of treatment. CONCLUSIONS Microsporidial keratoconjunctivitis can occur more commonly than expected in healthy, nonimmunocompromised individuals. Topical steroids seem to contribute to the persistence of this infection and may be a predisposing factor in these cases by creating a localized immunocompromised state. The clinical course is variable and may be self-limiting with cessation of topical steroid use.

Ocular surface changes in pterygium

Purpose. To evaluate ocular surface abnormalities in eyes with pterygium. Methods. Impression cytology was performed on 56 pterygia in 50 eyes with primary or recurrent pterygium. Superior, inferior, nasal, and temporal bulbar conjunctivae were evaluated. Results. The ocular surface morphology directly over the pterygium was found to be abnormal in 100% of cases. This was significant compared with abnormalities in 2.4% in the superior bulbar conjunctiva, 54.5% in the inferior bulbar conjunctiva, and 58.1% in the clinically unaffected interpalpebral conjunctiva. The epithelial cells in pterygium demonstrated squamous metaplasia in 73.2% of cases, with marked enlargement and elongation of the cells and pyknotic changes in the nuclei. Squamous metaplasia was also seen in the inferior conjunctiva (31.7%) and the clinically unaffected interpalpebral conjunctiva (54.8%) but without the advanced changes seen over the pterygium (p < 0.001). A low cellular yield was obtained over the pterygium in 98.2% of cases but only 22.7% in the inferior conjunctiva and 22.6% in the clinically unaffected interpalpebral conjunctiva (p < 0.001). Mucinous hyperplasia signifying increased goblet cell density was observed over the surface of the pterygium in 87.5% compared with 2.4% in the superior conjunctiva, 15.9% in the inferior conjunctiva, and 12.9% in the clinically unaffected interpalpebral conjunctiva (p < 0.001). Conclusion. The cytology of surface cells in pterygium exhibits squamous metaplasia with increased goblet cell density. A graded series of ocular surface changes exists throughout the bulbar conjunctiva in eyes with pterygium, with the most advanced changes occurring directly over the pterygium surface.

Conjunctival rotation autograft for pterygium: An alternative to conjunctival autografting

OBJECTIVE To determine the safety and efficacy of conjunctival rotation autografting (CRA) as an alternative to conventional conjunctival autograft after pterygium excision. DESIGN Prospective noncomparative case series. PARTICIPANTS Consecutive patients seen at the Pterygium Clinic of the Singapore National Eye Centre who were thought to be unsuitable for conventional conjunctival autografting underwent a modified surgical procedure, which the authors describe as CRA. There were 51 rotation autografts performed on 45 eyes of 43 patients. INTERVENTION In this procedure, the underlying fibrovascular pterygium tissue was removed and the original epithelium (with minimal subepithelial tissue included) replaced over the bare sclera with a 180 degrees rotation. Surgeries were performed by one surgeon (DT) from April 1995 to May 1996. MAIN OUTCOME MEASURE Pterygium recurrence and complications of CRA were measured. RESULTS The mean follow-up time was 12 months (range, 2-22 months). There were 46 primary and 5 recurrent pterygia. The indications for CRA were combined cataract and pterygium surgery (39.2%), double pterygia (31.4%), the need to preserve the superior conjunctiva (21.6%), and superior conjunctival scarring (7.8%). There were two recurrences (4% recurrence rate), one occurring at 4 months and the other occurring at 7 months after surgery. No significant complications were encountered. However, 50% of the grafts remained mildly injected for more than 3 months, and some remained injected for up to 13 months after surgery (average of 4 months). Pigmentary changes were also noted in six grafts (12%). CONCLUSION Conjunctival rotation autografting is a useful technique of conjunctival grafting in cases in which it is not possible or desirable to use the superior conjunctiva as a donor source.

Emerging Prevalence of Microsporidial Keratitis in Singapore: Epidemiology, Clinical Features, and Management

OBJECTIVE To investigate the incidence and epidemiologic factors involved in the development of microsporidial keratitis. The association of host immune status and clinical pattern, clinical features, and the role of fluoroquinolone monotherapy in treatment are also examined. DESIGN Retrospective, noncomparative case series. PARTICIPANTS All cases (124 patients, 134 eyes) of microsporidial keratitis confirmed with modified trichrome stain positive of corneal scrape over a 4-year period. METHODS Epidemiologic factors were observed. Host immune status with human immunodeficiency virus (HIV) serology and CD4/CD8 analysis was performed when consent was obtained. Visual acuity (VA) and slit-lamp examination throughout the course of keratitis was recorded. Treatment used included topical fluoroquinolones (ciprofloxacin 0.3%, moxifloxacin 0.5%, gatifloxacin 0.5%, levofloxacin 0.5%, or norfloxacin 0.3%) as monotherapy or in combination with topical fumagillin and/or systemic albendazole. Where corneal edema developed, ultrasound corneal pachymetry was recorded. MAIN OUTCOME MEASURES Demographic features and epidemiologic factors, including host immune status. Clinical features and disease course, including the response to different therapeutic regimes. RESULTS Patients ranged in age from 11 to 68 years (mean, 31.9; median, 30) with a male:female ratio of 8:1 (females n = 17 [13.7%]). We performed HIV serology and CD4/CD8 in 45.9% of cases (n = 57); all the cases tested were negative with normal T-cell indices. Epidemiologic factors included soil exposure (50%), contact lens wear (21.1%), and topical steroid treatment (17.1%). The VA on presentation ranged from 20/20 to 20/100 (median, 20/30) with no loss in lines of VA on resolution. Common features were follicular papillary conjunctivitis and coarse punctate epithelial lesions in 3 patterns--diffuse, peripheral, and paracentral--evolving into nummular keratitis before resolution. Resolution occurred in 99% of cases on topical fluoroquinolone monotherapy. Four patients had recurrent disease that resolved with repeat fluoroquinolone or fluoroquinolone/oral albendazole combination. Two new clinical features were identified--diffuse endotheliitis (19.4%) with corneal edema and limbitis. CONCLUSIONS This study identifies an increasing incidence of microsporidial keratitis in Singapore with a strong correlation with prior soil exposure. Diffuse endotheliitis and limbitis have not been described and resolves with topical steroid therapy. Topical fluoroquinolone monotherapy is a valid treatment option.

Microsporidial keratoconjunctivitis in a healthy contact lens wearer without human immunodeficiency virus infection.

PURPOSE To present a rare case of microsporidial keratoconjunctivitis in an otherwise healthy contact lens wearer without human immunodeficiency virus infection who responded to treatment with systemic albendazole and topical fumagillin. DESIGN Interventional case report. METHOD A cornea epithelial scraping from a man with unilateral keratoconjunctivitis previously treated with topical steroids was evaluated by modified trichome staining. MAIN OUTCOME MEASURES The patient was evaluated for his symptoms, visual acuity, clinical observations, and pathologic examination of corneal scrapes. RESULTS Modified trichome staining of an epithelial corneal scraping revealed pinkish to red organisms characteristic of microsporidia. Results of a human immunodeficiency virus (HIV) enzyme-linked immunosorbent assay test were negative. The symptoms of ocular discomfort and clinical signs of keratoconjunctivitis resolved after 2 months of treatment with albendazole and topical fumagillin. CONCLUSIONS Ocular infection with microsporidia, although classically occurring in patients with HIV infection, may occur rarely in healthy individuals, especially if previously treated with systemic immune suppression or topical steroids. Microsporidial keratoconjunctivitis should be considered in the differential diagnosis of a contact lens wearer with atypical multifocal diffuse epithelial keratitis.

Refractive lenticule extraction flap and stromal bed morphology assessment with anterior segment optical coherence tomography

Purpose To evaluate the flap and stromal bed after refractive lenticule extraction using optical coherence tomography (OCT). Setting Singapore National Eye Centre, Singapore. Design Longitudinal case series. Methods Horizontal scans (RTVue) were taken preoperatively and after refractive lenticule extraction. Two procedures were performed: femtosecond lenticule extraction and small‐incision femtosecond lenticule extraction. Flap and bed thicknesses were measured at the center (0.0 mm) and 1.5 mm and 3.0 mm to either side. Results At 1 week, the mean flap at 0.0 mm was borderline thicker (P=.056) and at +3.0 mm significantly thicker after femtosecond lenticule extraction than after small‐incision femtosecond lenticule extraction (P=.003). The mean bed at 0.0 mm was thinner after femtosecond lenticule extraction (P=.03). The flap at −3.0 mm showed thinning between 1 week and 3 months after small‐incision femtosecond lenticule extraction (P=.018). The flap at +3.0 mm thinned between 1 week and 1 month after femtosecond lenticule extraction (P=.009). After femtosecond lenticule extraction, there were increases in bed (P=.027) and total corneal (P=.013) thicknesses at 0.0 mm between 1 week and 3 months, remaining stable thereafter (3 months: P=.842 and P=.508, respectively). The mean spherical equivalent decreased and the uncorrected acuity improved after both procedures (P<.001), with stabilization of both variables at 3 months. Conclusion A significant difference in stromal bed thickness between femtosecond lenticule extraction and small‐incision femtosecond lenticule extraction was detectable by AS‐OCT 1 week postoperatively. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Refractive lenticule extraction: Transition and comparison of 3 surgical techniques

Purpose To describe the transition and outcomes of 3 refractive lenticule extraction (ReLEx) techniques: femtosecond lenticule extraction (FLEx), small‐incision lenticule extraction (SMILE), and pseudo small‐incision lenticule extraction. Setting Singapore National Eye Center, Singapore. Design Prospective comparative case series. Methods Refractive lenticule extraction was performed between March 1, 2010, and November 1, 2012, using the Visumax 500 kHz femtosecond laser system. The main outcome measures were the refractive efficacy, predictability, and safety over 12 months. Results The study enrolled 88 eyes. All 3 refractive lenticule extraction techniques yielded good refractive outcomes and stability over 12 months. Three months postoperatively, the mean overall efficacy index of refractive lenticule extraction was 0.89 ± 0.22 (SD), with 95.5% of eyes attaining an uncorrected distance visual acuity (UDVA) of better than 20/40 and 60.2% of better than 20/20. Of all eyes, 95.5% were within ±1.00 diopter (D) and 78.4% within ±0.50 D of the attempted correction. The mean overall safety index was 1.06 ± 0.17. At 3 months, all small‐incision lenticule extraction eyes and 96.7% of pseudo small‐incision lenticule extraction eyes had a UDVA of 20/40 or better, while femtosecond lenticule extraction eyes had a lower efficacy index (87.0%). However, efficacy was comparable in all 3 groups by 12 months (mean 0.87 ± 0.04 [standard error of the mean]; P = 1.00). Conclusion The efficacy, safety, and predictability profiles of the 3 refractive lenticule extraction techniques were good over a 12‐month follow‐up. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Vascular patterns in pterygium and conjunctival autografting: a pilot study using indocyanine green anterior segment angiography.

AIMS To characterise the vasculature of pterygium using indocyanine green (ICG) anterior segment angiography and to demonstrate the pattern of revascularisation following conjunctival autografting. METHODS ICG anterior segment angiography was performed on nine patients with pterygium. Angiography was repeated at 1–2 weeks and 2 months following conjunctival autografting in these patients. RESULTS Angiography showed a single feeder vessel originating from the anterior conjunctival circulation in six cases (66.7%). This vessel branched to form the radial vessels of the pterygium. Following conjunctival autografting, reperfusion of the vessels in the conjunctival autograft was demonstrable as early as 1 week postoperatively from the episcleral bed. At 2 months postoperatively, the graft appeared well perfused with mild leakage demonstrable at the edges of the graft. CONCLUSIONS A single feeder vessel from the anterior conjunctival circulation branches to form the radial vessels in pterygium. Reperfusion of conjunctival autografts occurs as early as 1 week postoperatively from the episcleral bed.

Visual outcomes comparison of 2 femtosecond laser platforms for laser in situ keratomileusis

Purpose To compare the efficacy, predictability, and safety outcomes of 2 femtosecond laser platforms for flap creation during laser in situ keratomileusis (LASIK) for myopia and myopic astigmatism. Setting Singapore National Eye Centre, Singapore. Design Retrospective case review. Methods In this single‐center multisurgeon study, patients had LASIK with flaps created using a Visumax 500 kHz or Intralase 60 kHz femtosecond laser system. Ablation was performed with the Wavelight Allegretto Eye‐Q 400 Hz excimer laser in all patients. Preoperative and 3‐month postoperative manifest refraction, attempted treatment spherical equivalent (SE), visual acuity, and complications were compared. Results The 500 kHz femtosecond laser group comprised 381 patients (381 eyes) and the 60 kHz femtosecond laser group, 362 patients (362 eyes). Three months postoperatively, the uncorrected distance visual acuity was 20/40 or better in 99.1% of eyes in the 60 kHz laser group and 99.4% of eyes in the 500 kHz laser group (P=.678). Regarding predictability, 98.6% of eyes and 97.4% of eyes, respectively, were within ±1.0 diopter of the attempted SE correction postoperatively (P=.228). The safety index was similar in the 60 kHz laser group and the 500 kHz laser group (mean 1.06 ± 0.16 [SD] versus 1.05 ± 0.14) (P=.321). Conclusion The safety, predictability, and efficacy profiles of the 500 kHz femtosecond platform for LASIK were excellent and comparable to those of the 60 kHz platform. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Incidence and management of suction loss in refractive lenticule extraction

Purpose To describe the incidence, management, and outcomes of suction loss in refractive lenticule extraction (ReLEx). Setting Tertiary eye hospital. Design Retrospective case series. Method All patients who experienced suction loss during refractive lenticule extraction from March 9, 2010, to August 5, 2013, were evaluated preoperatively, including slitlamp biomicroscopy, fundoscopy, corneal topography, ultrasound pachymetry, manifest and cycloplegic refractions, and measurement of uncorrected (UDVA) and corrected (CDVA) distance visual acuities. Patients were followed at predetermined timepoints. At each follow‐up visit, the UDVA and CDVA were measured and slitlamp biomicroscopy was performed. Manifest refraction was measured 1 and 3 months postoperatively. Results During the study period, 340 refractive lenticule extractions were performed. The overall cumulative incidence of suction loss was 3.2%. The incidence of suction loss was 4.3% (2/46) for femtosecond lenticule extraction, 4.4% (8/183) for small‐incision lenticule extraction, and 0.9% (1/109) for pseudo small‐incision lenticule extraction. Of the 11 eyes in which suction loss occurred, 8 (72.7%) had a UDVA of 20/30 or better and 9 (81.8%) had a spherical equivalent within ±0.5 diopter of emmetropia at 3 months. Suction loss occurred in 4 eyes during the posterior lenticule cut, in 5 eyes during the anterior lenticule cut, and in 2 eyes during the lamellar flap cut. In 9 of these (81.8%), suction was reapplied and the procedure was completed without further complications. Conclusions The incidence of suction loss during refractive lenticule extraction was relatively low. Good visual outcomes were achieved with appropriate management. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.