Purpose: This study aimed to explore the practices of optometrists in Hong Kong towards diagnosing and managing dry eye disease (DED). Methods: From September 2021 to March 2022, an online questionnaire was distributed to optometrists in Hong Kong through several professional associations. The questionnaire included questions about the importance and usefulness of various diagnostic tests, as well as inquiries about management strategies and recommended follow-up schedules for DED. Responses were compared between optometrists who were more or less proactive in continuing education to identify potential differences. Results: The analysis included 68 valid responses. Sixty-one of them were Part 1 optometrists that represents 5.5 % of registered Part 1 optometrists back in 2022. Assessment of clinical symptoms was the most commonly performed investigation (93 %) and considered the most important (75 %) procedure in DED assessments, followed by corneal staining and fluorescein tear break-up time. Traditional diagnostic tests were preferred over newer methods, such as osmolarity, which were not yet commonly used. Unpreserved lubricants (90 %) and lid hygiene (63 %) were the primary treatments recommended for mild DED. Optometrists who had more experience and frequent participation in continuing education were more confident in diagnosing and managing DED, and more likely to recommend omega-3 supplements for moderate DED. Conclusion: The diagnostic and management strategies of optometrists in Hong Kong were generally consistent with the recommendations of the Dry Eye Workshop II report. However, standardized DED questionnaires and newer diagnostic tools were not commonly used. Evidence-based optometric care for dry eye management should be encouraged in Hong Kong optometric practice.
It is important to be able to measure the range of clear focus in clinical practice to advise on presbyopia correction techniques and to optimise the correction power. Both subjective and objective techniques are necessary: subjective techniques (such as patient reported outcome questionnaires and defocus curves) assess the impact of presbyopia on a patient and how the combination of residual objective accommodation and their natural DoF work for them; objective techniques (such as autorefraction, corneal topography and lens imaging) allow the clinician to understand how well a technique is working optically and whether it is the right choice or how adjustments can be made to optimise performance. Techniques to assess visual performance and adverse effects must be carefully conducted to gain a reliable end-point, considering the target size, contrast and illumination. Objective techniques are generally more reliable, can help to explain unexpected subjective results and imaging can be a powerful communication tool with patients. A clear diagnosis, excluding factors such as binocular vision issues or digital eye strain that can also cause similar symptoms, is critical for the patient to understand and adapt to presbyopia. Some corrective options are more permanent, such as implanted inlays / intraocular lenses or laser refractive surgery, so the optics can be trialled with contact lenses in advance (including differences between the eyes) to better communicate with the patient how the optics will work for them so they can make an informed choice.
INTRODUCTION: Anti-mitosis has been a key strategy of anti-cancer therapies, targeting at a fundamental property of cancer cells, their non-controllable proliferation due to overactive mitotic divisions. For improved anti-cancer therapies, it is important to find out whether cancer cells can proliferate independent of mitosis and become resistant to anti-mitotic agents. RESULTS: In this study, live-cell imaging was applied to both primary-cultures of tumor cells, and immortalized cancer cell lines, to detect aberrant proliferations. Cells isolated from various malignant tumors, such as Grade-III hemangiopericytoma, atypical meningioma, and metastatic brain tumor exhibit distinct cellular behaviors, including amoeboid sequestration, tailing, tunneling, nucleic DNA leakage, as well as prokaryote-like division such as binary fission and budding-shedding, which are collectively referred to and reported as 'non-mitotic proliferation' in this study. In contrast, benign tumors including Grade-I hemangiopericytoma and meningioma were not obvious in such behaviors. Moreover, when cultured in medium free of any anti-cancer drugs, cells from a recurrent Grade-III hemangiopericytoma that had been subjected to pre-operation adjuvant chemotherapy gradually shifted from non-mitotic proliferation to abnormal mitosis in the form of daughter number variation (DNV) and endomitosis, and eventually regular mitosis. Similarly, when treated with the anti-cancer drugs Epirubicin or Cisplatin, the cancer cell lines HeLa and A549 showed a shift from regular mitosis to abnormal mitosis, and further to non-mitosis as the dominant mode of proliferation with increasing drug concentrations. Upon removal of the drugs, the cells reversed back to regular mitosis with only minor occurrences of abnormal mitosis, accompanied by increased expression of the stem cell markers ALDH1, Sox, Oct4 and Nanog. CONCLUSIONS: The present study revealed that various types of malignant, but not benign, cancer cells exhibited cellular behaviors indicative of non-mitotic proliferation such as binary fission, which was typical of prokaryotic cell division, suggesting cell level atavism. Moreover, reversible transitions through the three modes of proliferation, i.e., mitosis, abnormal mitosis and non-mitosis, were observed when anticancer drug concentrations were grossly increased inducing non-mitosis or decreased favoring mitosis. Potential clinical significance of non-mitotic proliferation in cancer drug resistance and recurrence, and its relationship with cancer stem cells are worthy of further studies.
Traditional Chinese Medicine has a long history in ophthalmology in China. Over 250 kinds of Traditional Chinese Medicine have been recorded in ancient books for the management of eye diseases, which may provide an alternative or supplement to current ocular therapies. However, the core holistic philosophy of Traditional Chinese Medicine that makes it attractive can also hinder its understanding from a scientific perspective - in particular, determining true cause and effect. This review focused on how Traditional Chinese Medicine could be applied to two prevalent ocular diseases, glaucoma, and cataract. The literature on preclinical and clinical studies in both English and Chinese on the use of Traditional Chinese Medicine to treat these two diseases was reviewed. The pharmacological effects, safety profile, and drug-herb interaction of selected herbal formulas were also investigated. Finally, key considerations for conducting future Traditional Chinese Medicine studies are discussed.
Cataract , Glaucoma , Humans , Medicine, Chinese Traditional , China , Glaucoma/drug therapy
CLINICAL RELEVANCE: Contact lens neophytes often learn about contact lens insertion and removal through YouTube videos of unknown quality. BACKGROUND: This study evaluates the quality of soft contact lens insertion and removal videos on YouTube. METHODS: A search for the keywords 'Contact lens insertion', 'Contact lens removal', 'Put in contact lens', and 'Take off contact lens' was performed on YouTube. The first 50 videos for each keyword were evaluated. The number of views, source of the publisher, days since upload, and video quality were scored based on the content in the videos. The maximum score of insertion and removal videos were 7 and 5 respectively. The videos were classified into three groups by publisher category: videos published by eye care professionals, companies and YouTubers. RESULTS: Only 45 contact lens insertion and 44 removal videos met the inclusion criteria and were analysed. Insertion and removal videos published by YouTubers had the highest view and view rate. However, their quality scores were significantly lower than videos published by eye care professionals and companies. Videos uploaded by companies had the highest scores (insertion: 5.00 ± 1.10; removal: 3.25 ± 0.75). The mean scores of insertion and removal videos published by YouTubers were 1.65 ± 0.93 and 1.00 ± 0.89, respectively, while the insertion and removal videos uploaded by eye care professionals scored 3.58 ± 2.07 and 2.75 ± 1.53, respectively. There was also a negative correlation between the quality scores and view rate (p = 0.008, r = -0.41). CONCLUSION: Contact lens insertion and removal videos uploaded by YouTubers had the highest view rate but the lowest quality. Videos made by companies included most essential elements.
Orthokeratology (ortho-k) is the process of deliberately reshaping the anterior cornea by utilising specialty contact lenses to temporarily and reversibly reduce refractive error after lens removal. Modern ortho-k utilises reverse geometry lens designs, made with highly oxygen permeable rigid materials, worn overnight to reshape the anterior cornea and provide temporary correction of refractive error. More recently, ortho-k has been extensively used to slow the progression of myopia in children. This report reviews the practice of ortho-k, including its history, mechanisms of refractive and ocular changes, current use in the correction of myopia, astigmatism, hyperopia, and presbyopia, and standard of care. Suitable candidates for ortho-k are described, along with the fitting process, factors impacting success, and the potential options for using newer lens designs. Ocular changes associated with ortho-k, such as alterations in corneal thickness, development of microcysts, pigmented arcs, and fibrillary lines are reviewed. The safety of ortho-k is extensively reviewed, along with an overview of non-compliant behaviours and appropriate disinfection regimens. Finally, the role of ortho-k in myopia management for children is discussed in terms of efficacy, safety, and potential mechanisms of myopia control, including the impact of factors such as initial fitting age, baseline refractive error, the role of peripheral defocus, higher order aberrations, pupil size, and treatment zone size.
Astigmatism , Contact Lenses , Myopia , Orthokeratologic Procedures , Refractive Errors , Child , Cornea , Corneal Topography , Humans , Myopia/therapy , Refraction, Ocular
PURPOSE: The aim was to assess the consistency of corneal epithelial cell viability of an ex vivo porcine eye model. METHOD: Six porcine eye models (four test and two control) were prepared for each experiment. The model has a computer-controlled mechanical arm, which could move the eyelid of the porcine eye and apply phosphate buffered saline to simulate blinking and lacrimation. The four test eyes were set up to simulate evaporative dry eyes with simulated lacrimation and blinking (one blink and one drop of buffered saline per minute) over three hours. Control A models were set up to collect pre-experimental baseline data, while those of control B were the same as the test eyes but without lacrimation and blinking simulation. All porcine eyes were kept in a closed chamber with temperature and humidity well controlled. After three hours, the cells of all eyes (except control A, which were assessed immediately before commencement of the experiment) were assessed. The eyes were first dipped into 0.4 per cent trypan blue solution. Following the dissection and separation of the cells, the number of dead cells were then counted under the microscope with a field size of 0.25 mm(2). The experiment was repeated 11 times. RESULTS: No significant differences were found in the number of dead cells among the four test eyes in both the central and peripheral cornea. There were significantly more dead cells in the test eyes compared to control A but significantly less when compared to control B. More dead cells were found in the central cornea than the peripheral cornea in the test eyes but the difference was not observed in controls A and B. CONCLUSION: Epithelial cell viabilities among the four porcine eye models with simulated lacrimation and blinking were consistent. The majority of cells were viable before the experiment and simulated lacrimation and blinking maintained more viable cells over time.
Dry Eye Syndromes/pathology , Epithelium, Corneal/pathology , Animals , Blinking , Cell Survival , Disease Models, Animal , Dry Eye Syndromes/physiopathology , Swine
AIM: To investigate whether cosmetic contact lenses (CCL) with surface pigments affect microbial adherence. METHOD: Fifteen brands of CCL were purchased from optical, non-optical retail outlets, and via the Internet. A standardized rub-off test was performed on each CCL (five lenses per brand) to confirm the location of the pigments. The rub-off test comprised gentle rubbing on the surfaces of each CCL with wetted cotton buds for a maximum of 20 rubs per surface. A new set of CCL (five lenses per brand) were incubated in Pseudomonas aeruginosa overnight. Viable counts of adhered bacteria were determined by the number of colony-forming units (CFU) on agar media on each lens. The adherence of P. aeruginosa as well as Staphylococcus aureus and Serratia marcescens to three brands of CCL (A-C) (five lenses per brand) were also compared to their adherences on their clear counterparts. RESULTS: Only two of the 15 brands of CCL tested (brands B and C) had pigments that did not detach with the rub-off test. The remaining 13 brands of CCL all failed the rub-off test and these lenses showed higher P. aeruginosa adherence (8.7 × 10(5)-1.9 × 10(6) CFU/lens). Brands B and C lenses showed at least six times less bacterial adhesion than the other 13 brands. Compared to their clear counterparts, bacterial adherence to brands B and C lenses did not differ significantly, whereas brand A lenses showed significantly higher adherence. CONCLUSION: Surface pigments on CCL resulted in significantly higher bacterial adherence.
Bacterial Adhesion/drug effects , Coloring Agents/chemistry , Contact Lens Solutions/pharmacology , Contact Lenses/microbiology , Cosmetic Techniques/instrumentation , Disinfection/methods , Adsorption , Coloring Agents/analysis , Contact Lens Solutions/chemistry , Equipment Contamination/prevention & control , Equipment Design , Equipment Failure Analysis , Surface Properties
PURPOSE: To compare the axial length elongation and change in refractive errors in a pair of identical twins wearing orthokeratology (ortho-k) and single vision lenses (SVLs), respectively. CASE REPORT: Identical Twin A and B, who were 8 years of age, with the same amount of near activities, were assigned to wear ortho-k and SVLs randomly and they were monitored for two years for myopic progression. Twin A and B were assigned to wear ortho-k and SVLs, respectively. Myopic progression was evaluated by the change in axial length and in refractive errors. A faster axial length elongation was observed in each eye of Twin B during the two-year study period. The overall change in axial length was 0.52mm (OD) and 0.70 (OS) in Twin A and 0.77mm (OD) and 0.82mm (OS) in Twin B. In terms of cycloplegic refractive errors (SER), one month after ceasing lens wear (after completion of the two-year study), the increase (from baseline) were 11% (OD) and 48% (OS) in Twin A and 87% (OD) and 67% (OS) in Twin B. CONCLUSIONS: Ortho-k is more effective in controlling myopic progression in terms of axial elongation than wearing SVLs in this pair of identical twins.
Contact Lenses , Myopia/diagnosis , Myopia/therapy , Orthokeratologic Procedures/instrumentation , Orthokeratologic Procedures/methods , Twins, Monozygotic , Disease Progression , Female , Humans , Male , Treatment Outcome
PURPOSE: To determine the prevalence of papillary changes of the upper palpebral conjunctiva and folliculosis of the lower palpebral conjunctiva in Chinese children with no history of contact lens wear. METHOD: Ninety-nine subjects (aged 6-15 years old) who were interested in a myopia control study were screened for papillary changes and folliculosis of the palpebral conjunctiva. Photodocumentation was performed under white and blue light (after the application of fluorescein) with a yellow filter and the photographs were graded by a group of practitioners according to a pre-set grading scale. Analysis was performed with the subjects divided into groups according to gender and age. RESULTS: More than 48% of the subjects had clinically significant (≥Grade 3) papillary changes in the upper palpebral conjunctiva. The prevalence of significant folliculosis in the lower lid was about 33%. The prevalence of significant papillary changes and folliculosis were similar between genders. No differences were observed between younger (age≤10 years old) and older (age>10 years old) in papillary changes but younger subjects showed a higher prevalence of folliculosis. CONCLUSIONS: The prevalences of clinically significant papillary changes and folliculosis of unknown aetiology are high in Chinese children.
Conjunctiva/pathology , Conjunctival Diseases/epidemiology , Diagnostic Techniques, Ophthalmological , Hong Kong/epidemiology , Adolescent , Child , Conjunctival Diseases/pathology , Contact Lenses , Female , Humans , Male , Prevalence , Reference Values , Reproducibility of Results , Retrospective Studies
PURPOSE: To report the clinical performance of the orthokeratology (ortho-k) lens fitted with computer assisted system after 1-month of lens wear, in a group of children undergoing ortho-k treatment in a 2-year randomized myopic control study. METHOD: Children aged 6-11 years old were fitted with the ortho-k lenses using computerized fitting. The initial myopia was 4.00-0.50 D and the initial refractive astigmatism was within 1.25 D. Lens performance, in terms of centration, myopic reduction, vision, ocular health status and lens binding incidence, was evaluated at one night, one week and one month after lens wear. Only data from the right eye was presented. RESULTS: The initial spherical equivalent refraction (SER) for the 51 subjects was -2.29 ± 0.81 D. The first fit success rate was 90%. The reduction of SER after one night and one week aftercare visit were 57% and 81%, respectively. At the one month visit, the mean reduction in SER was 89% with unaided logMAR visual acuity of 0.03 ± 0.11. Mild central corneal staining was found in 9-20% of the subjects at the aftercare visits. The incidences of lens binding at one night, one week and one month aftercare visits were 17%, 39% and 30%, respectively. CONCLUSIONS: Computer assisted system for Menicon Z Night lens fitting gave a high first fit success rate. Menicon Z Night lens was effective in myopic reduction and provided stable vision after one week of lens wear. Ocular health of the subjects after lens wear was generally unremarkable.
Contact Lenses , Myopia/therapy , Orthokeratologic Procedures , Therapy, Computer-Assisted , Asian People , Child , Corneal Topography , Humans , Myopia/physiopathology , Prosthesis Design , Prosthesis Fitting , Refraction, Ocular/physiology , Software , Visual Acuity/physiology
OBJECTIVE: The aim was to compare the thickness of each corneal sublayer and the visualization of superficial epithelial cells measured with the ConfoScan 4 (CS4) z-ring with and without the use of a soft contact lens and to evaluate the recovery rate of corneal staining after measurement with the CS4 (z-ring) with and without the application of artificial tears (ATs). METHODS: Twenty-eight subjects aged 18 to 35 years were recruited to have measurements with the CS4 (z-ring) on 2 different days. The measurements were performed over soft contact lenses (hydrogel lens or silicone hydrogel lens) on the first day and on the naked cornea on the second day. The recovery rates of the corneal staining induced by the measurements at the second visit were monitored for 5 hrs after measurements, one eye with the application of ATs and one eye without. RESULTS: No significant differences were found in the thicknesses of the central cornea and the sublayers measured with or without soft contact lenses. The intensity of epithelial cell images was improved with measurement made over hydrogel lenses, and on average, grade 3 (coverage) staining was observed in the corneas immediately after measurements without contact lenses. The recovery rate of the corneal staining did not improve with the application of ATs. CONCLUSIONS: Thickness measurements with the CS4 (z-ring) were not affected if made over soft contact lenses. The use of a soft lens to buffer the cornea during measurements was effective in eliminating corneal dehydration, preventing staining induced by the z-ring without affecting the corneal thickness measurement. It also enhanced epithelial image brightness, which may improve the accuracy in pachymetry.
Contact Lenses, Hydrophilic , Cornea/anatomy & histology , Microscopy, Confocal/methods , Adult , Cornea/drug effects , Cornea/metabolism , Female , Fluorescein/metabolism , Humans , Male , Microscopy, Confocal/instrumentation , Ophthalmic Solutions/pharmacology , Young Adult
PURPOSE: The aim was to determine the corneal parameters in low to moderate myopic Chinese children and to investigate the differences in these corneal parameters between male and female subjects. METHODS: Refractive errors and corneal parameters were retrieved from subjects who had participated in studies on myopia and astigmatism in 2008 and 2009. Corneal parameters including simulated K (Sim K) and asphericity (Q) at 9.0 mm chord and horizontal visible iris diameter (HVID) were determined for 217 children (112 males and 105 females aged from six to 12 years) using the Medmont E300 topographer. RESULTS: The Q of the corneas was -0.44 ± 0.12 along the flat meridian and -0.22 (-0.70 to 0.63) along the steep meridian. The HVID and Sim K of male subjects were larger and flatter than female subjects. The mean HVID of male and female subjects was 11.3 ± 0.3 mm and 11.1 ± 0.30 mm, respectively. The mean Sim K value in male and female subjects was 7.91 ± 0.24 mm and 7.79 ± 0.21 mm, respectively, along the flat meridian, and was 7.65 ± 0.26 mm and 7.53 ± 0.24 mm, respectively, along the steep meridian. CONCLUSIONS: All corneas were prolate elliptical in shape along the flat meridian and the peripheral flattening rate was found to be greater along the flat meridian. A greater flattening rate was observed in the corneas of Chinese children when compared to that of Caucasian children. The Q between male and female subjects was not significantly different. Male subjects tended to have larger HVID and flatter corneas than female subjects.
Asian People/statistics & numerical data , Astigmatism/ethnology , Astigmatism/pathology , Cornea/pathology , Myopia/ethnology , Myopia/pathology , Astigmatism/therapy , Child , Contact Lenses, Hydrophilic/statistics & numerical data , Female , Hong Kong/epidemiology , Humans , Male , Myopia/therapy , Prevalence , Severity of Illness Index , Sex Distribution
PURPOSE: To determine the repeatability of corneal sublayer thickness measurements using the Nidek ConfoScan 4 (CS4) with the z ring on a group of young adult subjects. METHODS: Thirty subjects aged 18 to 30 years were invited to have thickness measurements with the CS4 (z ring) on two different days, at similar time of the day to avoid diurnal variation. RESULTS: Only 22 subjects had valid measurements for analysis. The mean ± SD of central corneal thickness (CCT) was 534 ± 26 µm, epithelial thickness was 42 ± 8 µm, Bowman's layer thickness was 19 ± 7 µm, and stromal thickness (ST) was 472 ± 25 µm. There was no significant difference in the between-visit thickness measurements of each layer with the CS4 (z ring) (paired t-tests, p > 0.05). The limits of agreement of between-visit measurements were -41 (8%) to 37 µm (7%) for CCT, -21 (50%) to 19 µm (45%) for epithelial thickness, -13 (68%) to 17 µm (89%) for Bowman layer thickness, and -46 (10%) to 37 µm (8%) for ST. CONCLUSIONS: Measurements of CCT and ST with the CS4 (z ring) showed reasonably good repeatability (7 to 10%). However, the repeatability of measurements of the thinner corneal layers, such as epithelium and Bowman's layer, was poor.
Bowman Membrane/cytology , Epithelium, Corneal/cytology , Microscopy, Confocal/instrumentation , Adult , Equipment Design , Female , Humans , Male , Reference Values , Reproducibility of Results , Young Adult
