Ka Wai Kam

Long-term density changes in corneal layers after primary pterygium excision with topical Mitomycin-C

Purpose: To evaluate the long-term change in average corneal densities at 18 months after primary pterygium excision with topical adjuvant mitomycin-C application, particularly the relationship between anterior and posterior corneal layer densities. Methods: Prospective observational case series. Patients were imaged with the Pentacam at 18 months after their surgery. Average corneal densities were the primary outcome and were compared with postoperative weeks 1, 4, and 12 data using paired t test. Results: In all, 31 eyes of 31 patients were recruited. Mean age at time of operation was 62.0 ± 9.4 years. Mean best-corrected logarithm of the minimal angle of resolution visual acuity at 18 months was 0.14. The mean total anterior, central, and posterior average corneal densities were 30.6, 25.9, and 20.5 respectively. Compared with postoperative week 1 data, the anterior layer was reduced by 12.7% (P = 0.0144); however, there was no significant change in the central and posterior layers (P = 0.5353 and 0.0858, respectively). Subgroup analyses did not support the use of a 10- to 12-mm annulus as opposed to total-diameter data, and density reduction effect at 18 months from week 12 and week 1 seemed to be stronger in males (P = 0.0074 and 0.0042, respectively). Conclusions: Anterior corneal scars continued to diminish in density with time. Previous finding of a significant increase in posterior layer density at postoperative week 12 is likely not a result of optical phenomenon caused by a less dense anterior layer. Sex difference in terms of scar remodeling may be present.

Infliximab in the treatment of refractory ocular inflammatory diseases.

PurposeInfliximab is frequently used in the treatment of refractory rheumatic diseases. We report our initial local experience at a tertiary eye center in Hong Kong in using infliximab as treatment of various refractory ocular inflammatory diseases that have failed with conventional corticosteroid and immunosuppressant therapy. DesignThis is a retrospective, interventional case series. MethodsWe reviewed all the medical records of patients who had refractory ocular inflammatory diseases and received infliximab as part of their treatment. We collected data regarding the visual acuity, status of inflammation, and any complications arising from the treatment. ResultsSeven eyes from 3 male and 2 female patients were recruited. Two patients had peripheral ulcerative keratitis, whereas the remaining patients had uveitis. Two patients had bilateral diseases, and the rest were unilateral. All patients achieved quiescence after 3 doses of infliximab infusions during the period of 3 months. Most of the patients retained a useful visual acuity of 20/70 or better at the end of the study. There were no serious adverse effects or complications encountered from the infliximab therapy. ConclusionsInfliximab is a valuable and potent option that may be considered in the management of various refractory ocular inflammatory diseases. However, larger controlled studies are needed to evaluate the safety profile, optimal treatment schedule, and adverse effects of long-term infliximab therapy.

Topical Olopatadine in the Treatment of Allergic Conjunctivitis: A Systematic Review and Meta-analysis

ABSTRACT Purpose: To assess the safety and efficacy of topical olopatadine versus placebo and other topical anti-allergic medications in treating allergic conjunctivitis. Methods: We systematically searched the literature for randomized-controlled trials that included patients with allergic conjunctivitis, compared olopatadine versus placebo or alternative anti-allergic medications, and examined itch, conjunctival hyperemia, composite symptom or sign scores, and/or occurrence of adverse events. We assessed the safety and efficacy of topical olopatadine when compared with placebo or alternative anti-allergic medications using meta-analysis. Results: When compared with placebo, topical olopatadine is associated with a pooled-mean difference (MD) in ocular itch of –1.33 (p < 0.00001) and ocular hyperemia of –0.92 (p < 0.00001). When compared with other agents, olopatadine was inferior to alcaftadine on ocular itch (pooled-MD = 0.39; p < 0.00001) but comparable with epinastine and ketotifen. Conclusions: Topical olopatadine is a safe and effective treatment modality for allergic conjunctivitis, whereas alcaftadine appears to be superior to olopatadine in reducing ocular itch.

Infectious keratitis and orthokeratology lens use: a systematic review

PurposeMyopia is a prevalent condition among Asians. Orthokeratology lens has gained popularity as a method of myopia control. This systematic review is to summarize the clinical profile of infectious keratitis in association with orthokeratology lens wear.MethodsWe searched in the PubMed and EMBASE for articles adopting the search strategy “(orthokeratology lens OR orthokeratology) AND (bacterial eye infection OR keratitis OR cornea ulcer OR microbial keratitis OR bacterial keratitis)”, from the start date of the databases to August 23, 2016. Articles reporting infectious keratitis in orthokeratology lens users with data of individual cases were considered eligible for this systematic review. We recorded the outcome measures including method of diagnosis, etiological agents, duration and mode of treatment and treatment outcomes.ResultsOur literature search yielded 172 papers. After removing duplicated and irrelevant reports, we included 29 articles for data analysis, involving 173 eyes. Among all reported cases, the mean age at presentation was 15.4xa0±xa06.2xa0years, with a female preponderance (male-to-female ratio 1:1.7). Positive microbiological cultures were reported in 69.4% of cases, with Pseudomonas aeruginosa and Acanthamoeba being the most common etiological agents. The mean duration of hospitalization was 7.7xa0±xa06.7xa0days. Mean LogMAR visual acuity at presentation was 1.17xa0±xa00.78, increased to 0.33xa0±xa00.41 at final visit (pxa0<xa00.001).ConclusionsDespite early intervention and treatment, the majority of infections resulted in the formation of corneal scars and almost 10% of eyes needed surgical treatment. Timely awareness and treatment of keratitis should be emphasized to the users.

Painless Acanthamoeba Keratitis with Normal Vision

PURPOSEnTo report an atypical case of contact lens-related Acanthamoeba keratitis.nnnCASE REPORTnA 15-year-old secondary school female student with a history of soft contact lens wear was referred to our hospital by a private general practitioner for management of right eye redness and discomfort for 2 weeks. Upon examination, the best-corrected visual acuity was 20/20 and 20/16 for her right and left eyes, respectively. There was diffuse radial keratoneuritis noted in the cornea of her right eye without any associated epithelial defect. Corneal scraping was performed to induce epithelial defect over the keratoneuritis area, and it was positive for Acanthamoeba trophozoites. She was treated with amoebicidal therapy consisting of propamidine isethionate 0.1% and polyhexamethylene biguanide 0.02%, for 6 months. The patient did not complain of any ocular pain in the entire course of her disease. She attained a final visual acuity of 20/13 in the affected eye with residual peripheral radial perineuritic scar.nnnCONCLUSIONSnAtypical presentation of Acanthamoeba infection is uncommon. This case should arouse the awareness of an indolent presentation of this potentially sight-threatening disease. Clinicians should have a high level of suspicion in contact lens users who present with corneal abnormalities despite an absence of pain. Microbiological work-up and prompt treatment led to a complete resolution of Acanthamoeba infection in our patient.

Novel grid and sectoral analyses in monitoring corneal scars

PurposeWe aim to design two sampling methods, the grid and sectoral methods, to provide more precise detection of focal corneal scar changes with time following pterygium excision with the Pentacam imaging system.MethodsThis is a retrospective study of our previous prospective observational case series. Thirty patients underwent primary pterygium excision with adjuvant topical mitomycin-C application were followed up and imaged with Pentacam system at postoperative weeks 1, 4, 12 and month 18. Grid and sectoral methods were used to sample density changes (in grayscale units, GSU) over the scarred areas as well as the clear pole of the same cornea.ResultsUsing the grid method, the average corneal densities were 39.4, 37.1, 36.7 and 34.7xa0GSU at postoperative 1, 4, 12xa0weeks and 18xa0months, respectively. On the other hand, using the sectoral method, the average corneal densities were 35.3, 33.3, 32.5 and 31.9xa0GSU at postoperative 1, 4, 12xa0weeks and 18xa0months, respectively. Paired t tests achieved statistical significance when comparing all follow-up time points to first postoperative visit. A statistically significant effect of time on the average density was shown on ANOVA (pu2009<u20090.001) using both analyses over the scarred areas, but not over the clear pole of the same cornea (pu2009>u20090.05).ConclusionOur novel approach to monitor corneal density changes using the grid or sectoral sampling methods seemingly enhances the power in monitoring density changes in corneal scars when compared to conventional total-diameter average densitometry.

Analysis of multiple genetic loci reveals MPDZ-NF1B rs1324183 as a putative genetic marker for keratoconus

Objective To investigate the associations between 16 single-nucleotide polymorphisms (SNPs) in 14 genetic loci and keratoconus in an independent Chinese cohort. Methods This cross-sectional, case-control association study included a Chinese cohort of 133 patients with keratoconus and 371 control subjects. In a recent meta-analysis study, we identified association of 16 SNPs in 14 gene loci with keratoconus. In this study, we genotyped these 16 SNPs in all the patients and controls and analysed their association with keratoconus, its clinical severities and progression profiles. We also analysed the genotype-phenotype correlation between individual SNPs and steep keratometry, flat keratometry (Kf), average keratometry (Avg K) and best-fit sphere diameter (BFS) of the anterior and posterior corneal surface. Results Among the 16 selected SNPs, rs1324183 in the MPDZ-NF1B locus showed a significant association with keratoconus (OR=2.22; 95%u2009CI 1.42 to 3.45, p=4.30×10–4), especially severe keratoconus (OR=5.10, 95%u2009CI 1.63 to 15.93, p=0.005). The rs1324183 A allele was positively associated with anterior Kf (p=0.008), anterior Avg K (p=0.017), posterior Kf (p=0.01) and negatively associated with apex pachymetry (p=0.007) and anterior BFS (p=0.023) in keratoconus. The other 15 SNPs had no significant association with keratoconus or genotype-phenotype correlations. Conclusions This study confirmed the association of SNP rs1324183 in MPDZ-NF1B with keratoconus and revealed the association of this SNP with keratoconus severity and corneal parameters. It is thus a putative genetic marker for monitoring the progression of keratoconus to a severe form and facilitating early intervention.

Association of the PAX6 gene with extreme myopia rather than lower grade myopias

Aims To investigate the association of the paired box gene 6 (PAX6) with different severities of myopia. Methods A total of four haplotype-tagging single-nucleotide polymorphisms (SNPs; rs2071754, rs3026354, rs3026390 and rs628224) and two previously reported SNPs (rs644242 and rs662702) in the PAX6 gene were analysed in a Hong Kong Chinese cohort of 1288 myopia subjects (including 252 extreme myopia, 277 high myopia, 393 moderate myopia and 366 mild myopia) and 791 no myopia controls. Allelic association analyses were performed for individual SNPs in different subgroups of myopia and in combined myopia, followed by a meta-analysis of our current data with reported data on PAX6 in myopia. Results The association of tagging SNPs rs2071754 and rs644242 with extreme myopia could not withstand multiple correction (rs2071754: OR=1.25, P value=0.031; rs644242: OR=1.33, P value=0.032). In the meta-analysis, rs644242 showed an enhanced, significant association with extreme myopia (OR=1.27, 95%u2009CI 1.10 to 1.46, P value=0.001; I2=0%). In contrast, there was no significant association between the PAX6SNPs and high, moderate or mild myopia. No linear correlation was found between the PAX6SNPs and axial length. Conclusion This study provides additional evidence suggesting that the PAX6 SNP rs644242 is associated with extreme myopia but not lower grade myopia. Thus, PAX6 may be implicated in the development or progression into severe myopia. Further longitudinal studies are warranted.

Clinical features, diagnosis and treatment outcomes of cytomegalovirus endotheliitis in Hong Kong.

Editor, C orneal endotheliitis refers to the specific inflammation of corneal endothelium (Khodadoust & Attarzadeh 1982). The clinical features include corneal oedema, keratic precipitates, trace to moderate anterior chamber reaction and destruction of corneal endothelium (Alfawaz 2013). Cytomegalovirus (CMV) has been detected using polymerase chain reaction (PCR) and southern blot techniques in patients with corneal endotheliitis (Koizumi et al. 2006; Jhanji et al. 2013). We reviewed the data of patients who were diagnosed with CMV endotheliitis in the past 3 years in our hospital. Patients were identified from the clinical data and reporting system of the Hospital Authority of Hong Kong using prescription history of ganciclovir ointment or valganciclovir tablet. Overall, 17 eyes of 16 patients (nine males, seven females) were included. The median age at presentation was 57.5 years (range: 23–79 years), and the median age at diagnosis was 61.5 years (range: 34–80 years). The median duration between initial presentations to diagnosis of CMV endotheliitis was 1986 days (range: 19–4270 days). All patients were immunocompentent throughout the period of study. Prior to PCR confirmation of CMV endotheliitis, 12 eyes (70.6%) were labelled as anterior uveitis, and seven eyes (41.2%) were diagnosed as Posner–Schlossman syndrome. Overall, 14 eyes (82.4%) were treated for uveitic glaucoma. Before a diagnosis of CMV endotheliitis, all patients had received topical corticosteroid therapy (prednisolone acetate 1% ophthalmic suspension): nine eyes (52.9%) underwent cataract surgery with implantation of intraocular lens, and 10 eyes (58.8%) underwent trabeculectomy or needling. About three-fourths of cases in our series (13 eyes, 76.5%) were categorized as atypical CMV endotheliitis based on the diagnostic criteria proposed by the Japanese Corneal Endotheliitis Study Group (Koizumi et al. 2015). Clinical signs observed on slit lamp examination included localized corneal oedema (10 eyes, 58.8%), iris atrophy (five eyes, 29.4%), coin-shaped keratic precipitates (three eyes, 17.7%), linear keratic precipitates (one eye, 5.9%) and diffuse bullous keratopathy (one eye, 5.9%). During treatment, four eyes (23.5%) developed cataract. The mean LogMAR visual acuity was 0.38 0.54 at presentation and 0.70 0.62 at diagnosis (p = 0.093). The median intraocular pressure was 26 mmHg (range: 12– 58 mmHg) at presentation and 18 mmHg (range: 8–47 mmHg) at the time of diagnosis (p = 0.138). Initial treatment was started in the form of topical ganciclovir ointment (every 2 hours) in 13 eyes (81.2%) and oral valganciclovir (900 mg twice daily) in four eyes (23.5%). However, both topical and oral treatments were required during later stages of the disease. Overall, ganciclovir ointment was used in all (100%) patients, whereas oral valganciclovir was used in 13 patients (81.2%). The mean duration of antiCMV treatment was 12.4 6.7 months. The median follow-up period from time of diagnosis was 17 months (range: 5–29 months). The anterior chamber inflammation was controlled in 15 of 17 eyes (88.2%) at final follow-up with the addition of anti-CMV treatment to topical corticosteroids. One patient (5.8%) continued to develop bullous keratopathy despite treatment, and another patient (5.8%) underwent combined penetrating keratoplasty and phacoemulsification with intended aphakia after the diagnosis of CMV endotheliitis. The median intraocular pressure was significantly lower at final visit at 15 mmHg (range: 9–29 mmHg) as compared to the median intraocular pressure at presentation (p = 0.001). The mean number of anti-glaucoma medications was reduced from 3.71 1.69 to 1.65 1.17 between diagnosis and final follow-up after treatment (p = 0.001). However, there was no statistically significant difference between the final mean visual acuity (0.68 0.60) and mean visual acuity at presentation (p = 0.171) or diagnosis (p = 0.240). Our case series reflected a very wide range in the time lapse between symptomatic onset and final diagnosis of CMV endotheliitis. This was further suggested by the facts that our patients had a poor visual acuity at presentation, high rate of cataracts and history of glaucoma surgery at the time of diagnosis. Visual acuity at termination was partly affected by glaucomatous damage. The mean available visual field index at baseline was 95.5% and dropped to 88.8% at termination of study. The mean deviation (MD) was 3.77 at baseline and dropped to 6.15 at conclusion of study. Mild-tomoderate corneal haze may also have contributed to the poor visual acuity at the end of the study in our patients. Unfortunately, we did not have the optical coherence tomography data for determining the macular status. We observed from our series that during the initial years, a significant proportion of these patients presented with brief episodes of hypertensive anterioruveitis, which showed rapid response to topical corticosteroids in the beginning. However, in later years, the condition became chronic anterior uveitis with trace inflammation in the anterior chamber despite prolonged use of topical corticosteroids. The initiation of ganciclovir gel or oral valganciclovir often successfully controlled these inflammatory reactions that had not responded to topical corticosteroids alone. Up to this moment, there is no consensus on the treatment of CMV endotheliitis. Valganciclovir and ganciclovir are commonly used agents for treatment of CMV endotheliitis (PavanLangston et al. 2012). In our clinic, ganciclovir ointment is the preferred initial treatment for CMV endotheliitis. This choice is attributed to the absence of systemic adverse effects and low cost of ganciclovir ointment, as compared to oral valganciclovir. In summary, our study showed that CMV endotheliitis remains a rare yet important differential diagnosis for cases with hypertensive anterior uveitis. Care should be taken to examine the status of endothelium and/or presence Acta Ophthalmologica 2018

Long-Term Stability of Keratometry, Scheimpflug-Derived True Net Power, and Total Corneal Refractive Power after Primary Pterygium Excision

Purpose: To evaluate long-term changes in mean keratometry, astigmatism, true net power (TNP), and total corneal refractive power (TCRP) of corneas after primary pterygium excision. Methods: This is a prospective observational series conducted at a tertiary teaching hospital eye center in Hong Kong. A total of 31 eyes of 31 patients with primary pterygium excision were included. Patients with recurrent or double-headed pterygia or a history of corneal scars from previous trauma, infection, or surgery were excluded. Data were collected prospectively at postoperative weeks 1, 4, 12, and month 18. Results: Mean keratometry of the anterior cornea was 44.3 diopters (D) [95% confidence interval (CI): 43.6–44.9 D] at week 1, 44.3 D (95% CI: 43.6–44.9 D, standard error = 0.3) at week 4, 44.3 D (95% CI: 43.7–44.9 D) at week 12, and 44.1 D (95% CI: 43.5–44.7 D) at month 18. Mean astigmatism of the anterior cornea was 1.1 D (95% CI: 0.7–1.4 D), 1.0 D (95% CI: 0.7–1.3 D), 0.9 D (95% CI: 0.6–1.1 D), and 1.0 D (95% CI: 0.7–1.3 D) at postoperative 1, 4, 12 weeks, and 18 months, respectively. Mean keratometry, astigmatism of the anterior and posterior cornea, TNP and TCRP at 2.0-mm, 3.0-mm, 4.0-mm rings and zones remained unchanged on all follow-up visits (P = 1 for all comparisons). Conclusions: Keratometric values including TNP and TCRP were stable as soon as 1 week after pterygium excision. This information might help clinicians in planning subsequent intraocular surgery that requires biometric assessment for intraocular lens implantation.