Vigabatrin-induced visual dysfunction in Chinese patients with refractory epilepsy.

PURPOSE: Bilateral visual field constriction has been reported following the use of the antiepileptic drug (AED) vigabatrin. The incidence of retinal toxicity is variable and there are limited data in Asian populations. The authors report the results of ophthalmologic examination in Chinese patients taking this drug. METHODS: The authors identified two groups of patients with refractory epilepsy: one group on vigabatrin and another cohort of patients taking other AEDs. The authors recorded the medical history and performed visual acuity testing, intraocular pressure measurement, slit lamp biomicroscopy, and conventional automated perimetry with Humphrey Visual Field Analyzer II in all patients. RESULTS: Eighteen patients--8 men and 10 women--with a mean age of 23.8 years who were taking vigabatrin were reviewed. Length of treatment with this drug ranged from 13 months to 5 years and the mean daily dosage was 1581 mg. None of the patients in either group had a history of coexisting optic nerve diseases or other neurotoxic drug use. Twenty of 36 (55.6%) eyes of the vigabatrin users showed significant bilateral visual field defects with 80% showing a concentric pattern, compared with none in the control group. CONCLUSIONS: The authors confirmed a high prevalence of visual field constriction associated with vigabatrin in Chinese patients. The use of alternative novel techniques such as measurement of the retinal nerve fibre layer thickness and perimetry may detect early retinal damage and result in even higher incidences. Visual field monitoring is recommended in patients who continue to take this drug.

Genomic annotation of 15,809 ESTs identified from pooled early gestation human eyes.

To complement cDNA libraries from the human eye at early gestation and to discover candidate genes associated with early ocular development, we used freshly dissected human eyeballs from week 9-14 of gestation to construct the early human fetal eye cDNA library. A total of 15,809 clones were isolated and sequenced from the unamplified and unnormalized library. We screened 11,246 good-quality ESTs, leading to the identification of 5,534 nonredundant clusters. Among them, 4,010 (72%) genes matched in the human protein database (Ensembl). The remaining 28% (1,524) corresponded to potentially novel or previously unidentified ESTs. We used BLASTX to compare our EST data with eight organisms and found common expression of a high portion of genes: Caenorhabditis briggsae (26%), Caenorhabditis elegans (27%), Anopheles gambiae (37%), Drosophila melanogaster (32%), Danio rerio (42%), Fugu rubripes (49%), Rattus norvegicusvalitus (52%), and Mus musculus (59%). Nevertheless, 48% (2,680 of 5,534) of the genes expressed in the early developing eye were not shared with current NEIBank human eye cDNA data. In addition, eight known retinal disease genes existed in our ESTs. Among them, six (COL11A1, BBS5, PDE6B, OAT, VMD2, and PGK1) were conserved among the genomes of other organisms, indicating that our annotated EST set provides not only a valuable resource for gene discovery and functional genomic analysis but also for phylogenetic analysis. Our foremost early gestation human eye cDNA library could provide detailed comparisons across species to identify physiological functions of genes and to elucidate evolutionary mechanisms.

Molecular characterization of the developmental gene in eyes: through data-mining on integrated transcriptome databases.

OBJECTIVES: Our aim was to utilize publicly available and proprietary sources to discover candidate genes important for ocular development. DESIGN AND METHODS: The collated information on our 5092 non-redundant clusters was grouped and functional annotation was conducted using gene ontology (FatiGO) for categorizing them with respect to molecular function. The web-based viewer technological platform (H-InvDB) was employed for transcription analyses of in-house high quality fetal eye Expressed Sequence Tags (ESTs). Eye-specific ESTs were also analyzed across species by using EMBEST. RESULTS: According to adult eye cDNA libraries, nucleic acid binding and cell structure/cytoskeletal protein genes were the most abundant among the ESTs of fetal eyes. Using cDNA assembly in H-InvDB, 20 (80%) of the 25 most commonly expressed genes in the human eye are also expressed in extraocular tissues. The crystalline gamma S gene is highly expressed in the eye, but not in other tissues. We used EMBEST to compare human fetal eye and octopus eye ESTs and the expression similarity was low (1.6%). This indicated that our fetal eye library contains genes necessary for the developmental process and biological function of the eye, which may not be expressed in the fully developed octopus eyes. The human fetal eye cDNA library also contained highly abundant eye tissue genes, including alphaA-crystallin, eukaryotic translation elongation factor 1 alpha 1 (EEF1A1), bestrophin (VMD2), cystatin C, and transforming growth factor, beta-induced (BIGH3). CONCLUSIONS: Our annotated EST set provides a valuable resource for gene discovery and functional genomic analysis. This display will help to appreciate the strengths and weaknesses of the different technological platforms, so that in future studies the maximum amount of beneficial information can be derived from the appropriate use of each method.

Decreasing efficacy of repeated intravitreal triamcinolone injections in diabetic macular oedema.

BACKGROUND/AIM: Intravitreal triamcinolone (IVTA) results in transient improvements in diabetic macular oedema (DMO), necessitating repeated injections. The authors report a case series of 10 eyes of 10 patients with DMO, who received a repeat injection of 4 mg IVTA, at least 26 weeks after the first injection of the same dose. METHOD: Pre-injection and at 2, 4, 9, and 17 weeks post-injection, best corrected visual acuity (BCVA) and central foveal thickness (CFT) on optical coherence tomography, after the first and repeat injections, were compared using paired t test. Side effects were monitored. RESULTS: BCVA, CFT, intraocular pressure (IOP), and cataract scores were not significantly different before initial and repeat injections (given at 32.5 (SD 3.5) weeks after the first injection). Transient improvements of BCVA and CFT were achieved after both injections. However, after the repeat injection, the BCVA was significantly worse at all time points (p<0.05) and so were the best achieved CFT and the CFT at 4 weeks post-injection (p = 0.034 and 0.011 respectively), compared with the initial injection. Post-injection maximum IOPs and increase in cataract scores were not significantly different between the two injections. CONCLUSION: A repeat injection of 4 mg of IVTA may not be as effective as an initial injection for the treatment of DMO.

Safety enhanced photodynamic therapy with half dose verteporfin for chronic central serous chorioretinopathy: a short term pilot study.

AIM: To evaluate short term safety of an enhanced photodynamic therapy (PDT) protocol with half dose verteporfin for treating chronic central serous chorioretinopathy (CSC). METHODS: 20 eyes of 18 patients with symptomatic chronic CSC underwent PDT using 3 mg/m2 verteporfin. Verteporfin was infused over 8 minutes followed by indocyanine green angiography guided laser application 2 minutes later. Serial optical coherence tomography (OCT) and multifocal electroretinography (mfERG) recordings were performed before PDT, at 4 days, 2 weeks, and 1 month after PDT. The best corrected visual acuity (BCVA), OCT central retinal thickness, and mean mfERG response amplitudes and peak latencies were compared longitudinally. Subgroup analysis was further performed for eyes with or without pigment epithelial detachment (PED). RESULTS: At 1 month after PDT, the median BCVA improved from 20/40 to 20/30 (p = 0.001). The mean central retinal thickness also reduced from 276 microm to 158 microm (p < 0.001) and 17 (85%) eyes had complete resolution of serous retinal detachment and/or PED. MfERG showed no significant changes in the mean N1 and P1 response amplitude and latency for all eyes. Subgroup analysis demonstrated that eyes without PED had a significant increase in the mean central mfERG P1 response amplitude with reduction in P1 peak latency at 1 month post-PDT. For eyes with PED, transient reduction in the mean central P1 response amplitude was observed at 4 days post-PDT. CONCLUSIONS: The modified safety enhanced PDT protocol with half dose verteporfin appeared to be a beneficial treatment option for patients with chronic CSC, especially in eyes without serous PED. Further controlled study is warranted to demonstrate the long term safety and efficacy of this treatment option.

Combined photodynamic therapy and intravitreal triamcinolone injection for the treatment of subfoveal choroidal neovascularisation in age related macular degeneration: a comparative study.

AIM: To evaluate the outcomes of combined intravitreal triamcinolone (IVTA) and photodynamic therapy (PDT) with verteporfin in the treatment of subfoveal choroidal neovascularisation (CNV) caused by age related macular degeneration (AMD). METHODS: 48 eyes from 48 patients with subfoveal CNV caused by AMD were prospective recruited, with 24 eyes treated with combined PDT with IVTA and compared with a control group of 24 eyes which received PDT monotherapy. In the combined treatment group, IVTA was performed immediately after PDT as an outpatient procedure. The mean number of treatments, mean logMAR best corrected visual acuity (BCVA), mean line of visual acuity changes, and proportion of patients without moderate visual loss at 1 year were compared between the combined and monotherapy groups. RESULTS: At 1 year the logMAR BCVA for the PDT with IVTA group changed from 0.88 to 0.95 (p = 0.32 compared with baseline), whereas the logMAR BCVA for the monotherapy group reduced from 0.74 to 1.09 (p<0.001 compared with baseline). A significantly higher proportion of patients who had PDT with IVTA did not develop moderate visual loss at 1 year compared with the monotherapy group (70.8% and 33.3% respectively, p = 0.009). Eyes which had combined treatment had significantly fewer lines lost compared with monotherapy alone (0.7 and 3.5 lines respectively, p = 0.015). Subgroup analysis showed that PDT with IVTA is effective in preventing visual loss in both predominately classic and occult CNV groups. The mean number of treatments for the combined and monotherapy groups was 1.5 and 1.96 respectively (p = 0.076). CONCLUSIONS: Combined PDT with IVTA appeared more effective statistically at 12 months for stabilisation of vision (<3 logMAR lines change) compared with PDT monotherapy. Further randomised control trials might be justified to conclude the efficacy of PDT with IVTA.

Late leakage of filtering bleb in a patient with orbital pseudotumor.

PURPOSE: To report an unusual case of spontaneous late leakage of filtering bleb in a patient with orbital pseudotumor. METHODS: Single case report. RESULTS: A 53-year-old woman developed spontaneous leakage of bleb in her right eye 23 years after trabeculectomy with application of mitomycin-C (MMC). Two weeks later, her symptoms were blurring of vision, increasing redness, and dull ocular pain in the right eye. The inflammatory signs were suggestive of endophthalmitis, orbital cellulites, or pseudo-tumor. Absence of ophthalmoplegia, fever, and raised white cell count, together with the computed tomographic scan finding, confirmed the diagnosis of orbital pseudotumor. She responded well to oral steroids. CONCLUSIONS: Orbital pseudotumor may initially present with spontaneous late leakage in a bleb augmented by MMC. Orbital pseudotumor should be added to the list of differential diagnoses when facing a patient with an inflamed, chemotic, proptotic eye in the presence of a late bleb leak.

Gene mutations in retinitis pigmentosa and their clinical implications.

Retinitis pigmentosa (RP) is a group of inherited progressive retinal diseases affecting about 1 in 3500 people worldwide. So far, there is no prevention or cure, with permanent visual loss or even blindness the ultimate consequence usually after midlife. The genetics of RP are complex. It can be sporadic, autosomal dominant, autosomal recessive, or X-linked. Thirty-two genes are known to be associated with RP, sometimes the same gene gets involved in different inheritance traits. Some RP cases have a digenic cause. About 60% RP cases still have no known genetic cause. A large number of mutations cause RP, and they can be deletions, insertions, or substitutions that cause missense mutations or truncations. The RHO, RP1, and RPGR genes contribute the greatest number of known mutations causative of RP. But there is no single mutation that alone accounts for more than 10% of unrelated patients. Genetic testing for RP therefore requires screening for a group of genes. High-throughput and automated sequence detection technologies are essential. Due to the complexity in phenotype and genetics, and the fact that RP is untreatable, genetic testing for presymptomatic diagnosis of RP is controversial. Meanwhile, new genes are still to be identified, mostly by family linkage and sib-pair analysis. Research on gene therapy for RP requires information on gene mutations causative of RP.

Efficacy of pressure topical anaesthesia in punctal occlusion by diathermy.

AIMS: To prospectively compare the efficacy and safety of pressure topical anaesthesia in punctal occlusion by using cautery in the treatment of dry eye syndrome (DES) with that of conventional treatment by using needle injection of anaesthetic agents. METHODS: In a randomised controlled trial, 18 consecutive adult patients with DES requiring punctal occlusion were recruited over a 10 month period. Consenting patients were randomised into two groups. Group A patients received pressure topical anaesthesia in the right eye followed by injection anaesthesia in the left eye. Group B was vice versa. Punctal occlusion using cautery was performed in each eye after a specified time following the application of anaesthesia. The main outcome measures were the pain experienced during application of anaesthesia and that during punctal occlusion. RESULTS: 36 eyes of 18 patients were randomised to receive injection anaesthesia in one eye and pressure topical anaesthesia in the other. Nine patients (nine females) were in group A and nine patients (seven females, two males) in group B. The mean age of group A patients was 45.3 (SD 13.5) years, and that of group B patients was 55.6 (12.6) years. The two groups were comparable in terms of mean age (p=0.117) and mean pain score for pressure topical anaesthesia application (p=0.612), injection anaesthesia application (p=0.454), diathermy in pressure anaesthetised eyes (p=0.113), and diathermy in injection anaesthetised eyes (p=0.289). Paired t test was used to compare the mean pain score for pressure topical anaesthesia application (16.8 (24.8)) with those for injection anaesthesia application (56.7 (30.0)). 18 eyes of 18 patients were compared with the fellow eye of the same 18 patients. The mean pain score for injection anaesthesia was greater than for pressure topical anaesthesia application (p<0.0001) (statistical power=0.87). No statistically significant difference was found in the mean pain score for diathermy for eyes that received pressure topical anaesthesia (20.5 (27.5)) compared with eyes that received injection anaesthesia (23.1 (26.3)) (p=0.760) (statistical power=0.96). All 18 patients preferred pressure topical anaesthesia to injection anaesthesia. CONCLUSION: Injection anaesthesia for punctal occlusion is more painful than pressure topical anaesthesia application. However, the pain experienced during diathermy application for punctal occlusion is similar between pressure anaesthetised eyes and injection anaesthetised eyes. Pressure topical anaesthesia is a less painful (in terms of anaesthesia application) but equally effective alternative to conventional injection anaesthesia when used for punctal occlusion.

Choroidal neovascularisation in pathological myopia: an update in management.

Choroidal neovascularisation (CNV) secondary to pathological myopia is an important cause of significant visual impairment in young and middle aged adults globally and is particularly prevalent in Asian populations. In the past few years, there have been rapid advancements in the different treatments for myopic CNV. The purpose of this perspective is to give an overview of the natural history of myopic CNV and the various treatment options including laser photocoagulation, photodynamic therapy, sub-macular surgery, and macular translocation surgery. Future directions in the management of myopic CNV are also discussed.

Chloroquine-induced bull's eye maculopathy.

We report the case of a 51-year-old woman who presented with bilateral progressive deterioration in vision after taking chloroquine for severe rheumatoid arthritis for 10 years. She was found to have a bull's eye pattern of depigmentation in the macula of both eyes. Despite cessation of chloroquine, her vision did not improve. The clinical presentation of chloroquine retinopathy is discussed, along with the importance of scheduled eye examination for individuals taking chloroquine or hydroxychloroquine.

Causes of childhood blindness in a school for the visually impaired in Hong Kong.

OBJECTIVE: To identify the causes of blindness in children attending a school for the blind in Hong Kong. DESIGN: Cross-sectional observational study. SETTING: School for blind children in Hong Kong. PARTICIPANTS: Eighty-two blind students at the Ebenezer School and Home for the Visually Impaired were examined between December 1998 and August 1999. MAIN OUTCOME MEASURES: Demographic data were obtained from students and a questionnaire assessment made of their medical and ocular history. Visual acuity was assessed and visual loss classified according to the World Health Organization classification of visual impairment. Complete ophthalmic assessments were performed in all students including slit-lamp examination and dilated binocular indirect ophthalmoscopy. RESULTS: The mean age of the students was 12.2 years. Ten (12.2%) had a family history of eye disease. Major past medical illnesses were reported in 50% with prematurity and diseases of the central nervous system found in 26.8% and 11.0% of students, respectively. The most common anatomical site for visual impairment was the retina (47.6%), followed by diseases of the optic nerve (14.6%), and diseases of the anterior segment and the lens (14.6%). CONCLUSIONS: The pattern of childhood blindness in Hong Kong is similar to that seen in other developed countries. Preventable causes of childhood blindness, such as prematurity and birth asphyxia, were responsible for a large proportion of cases. Early diagnosis and treatment of such conditions may reduce the incidence of childhood blindness in Hong Kong.

Genetic markers for retinitis pigmentosa.

OBJECTIVE: To review recent advances in the molecular genetics of retinitis pigmentosa with emphasis on the development of genetic markers that aids diagnosis and prognosis. DATA SOURCES AND EXTRACTION: Literature search of MEDLINE from 1988 to 2005 using the following key words: 'retinitis pigmentosa', 'rhodopsin', 'RP1', 'RPGR', and 'genetic counseling'. References of two genes--RHO and RP1--causing retinitis pigmentosa in the Chinese population were reviewed. STUDY SELECTION: Literature and data related to genetic markers for retinitis pigmentosa. DATA SYNTHESIS: The genetics of retinitis pigmentosa is complex. It can be sporadic or familial, with heterogeneous transmission modes. Retinitis pigmentosa is associated with nearly 40 chromosomal loci, where 32 candidate genes have been identified. A large number of mutations are known to cause retinitis pigmentosa. But no single mutation alone accounts for more than 10% of unrelated retinitis pigmentosa patients. Genetic tests for retinitis pigmentosa require screening for a consort of mutations in a large number of genes. High throughput screening technology such as denaturing high performance liquid chromatography and automated DNA sequencing should make such tests feasible. CONCLUSIONS: Rapid developments in the understanding of the genetics of retinitis pigmentosa have helped to establish genetic tests of clinical value. The complex mode of inheritance nonetheless makes genetic counselling difficult, even in the presence of positive genetic screening results.

Genetic alterations on chromosome 19, 20, 21, 22, and X detected by loss of heterozygosity analysis in retinoblastoma.

PURPOSE: To explore the presence of common genetic alterations in retinoblastoma and to localize the altered genomic regions. METHODS: Genetic analysis included determinations of the loss of heterozygosity (LOH) and microsatellite instability (MSI) on chromosomes 19, 20, 21, 22, and X. Investigations were carried out among 15 microdissected retinoblastoma tumors and corresponding genomic DNA specimens. RESULTS: Among the 15 retinoblastoma cases, 73% (11/15) showed genome instability (LOH and/or MSI) at one or more loci on the 5 chromosomes, although loci with recurrent LOH was infrequent. The loss of a single allele was more frequent in chromosomes 19 (33%) and 20 (27%) than the other 3 chromosomes. Five loci with recurrent allelic loss were identified, among them the most frequent allelic losses were between D19S902 and D19S571 on 19q13 and were identified in 3 out of the 15 tumor specimens. The results suggested that gene loci in the 19q13 region may be associated with tumor development in retina. In addition, 3 specimens showed moderate frequency of LOH and/or MSI in more than 6 microsatellite markers, indicating genomic instability to occur at least in a subset of retinoblastoma. CONCLUSIONS: Our results provide the first evidence of LOH in chromosomes 19 and 20 in retinoblastoma. They also support the proposition that presence of genome instability in retinoblastoma may play a role in the tumorigenesis or progression of retinoblastoma.

The prevalence of pseudoexfoliation syndrome in Chinese people.

BACKGROUND: Pseudoexfoliation syndrome (PXS) is regarded as rare in people of Chinese ethnicity but the prevalence of this condition is not known. This epidemiology study was conducted to assess the prevalence of PXS in cataract patients and to report the clinical features present. METHODS: Prospective descriptive study conducted in the period from March 1999 to May 2001 in ophthalmology departments in cluster hospitals serving a population of about 1.2 million. 500 consecutive patients aged 60 or above attending the general ophthalmic clinics with a presumed diagnosis of cataract were recruited. A detailed examination including biomicroscopy, intraocular measurement, and gonioscopy were performed on all patients. All positive PXS cases were documented photographically. RESULTS: 500 patients were examined. They ranged from the ages of 60 to 91 years old, with a male to female ratio of 1:2. 40% suffered from hypertension while 24% were known diabetics. Only two positive cases (0.4%) of PXS were identified in the study population. 18% of all eyes were found to have narrow angles (defined as grade 0 to 2 by Shaffer grading). Nuclear sclerosis was the single most common type of lens opacity. CONCLUSION: PXS is a rare condition in Chinese people. A prevalence rate of 0.4% in patients aged 60 or above was identified in this hospital based epidemiology study. To the best of our knowledge, this was the first study conducted in a Chinese population to examine the prevalence of PXS.

Changing patterns of strabismus: a decade of experience in Hong Kong.

BACKGROUND/AIMS: Racial variation in the pattern of strabismus is known, but few large scale studies on non-white populations are available. Furthermore, longitudinal change in this pattern within a local setting has not been well documented in the past. This study aims to support the clinical impression that exotropia is more common in Chinese patients, and that the proportion of patients with exotropia has been increasing in the past decade. METHODS: A total of 2704 consecutive patients with the diagnosis of primary horizontal strabismus, seen in the strabismus clinic of the Hong Kong Eye Hospital, were retrospectively analysed to determine the relative prevalence of esotropia and exotropia. Characteristics recorded include patient demographics, type of strabismus, and whether the nature of the squint was constant or intermittent. RESULTS: 742 (27.4%) patients were found to have esotropia, 548 (20.3%) had constant exotropia, 1213 (44.9%) had intermittent exotropia, and 201 (7.4%) had microtropia. The proportion of exotropic to esotropic patients was shown to increase steadily throughout the past decade (p<0.0001). This was mainly accounted for by an increase in the number of patients with intermittent exotropia, and a corresponding decrease in the number of patients with esotropia. CONCLUSION: Exotropia was shown to be more prevalent than esotropia in a Hong Kong Chinese population. Furthermore, the proportion of patients with intermittent exotropia appears to be increasing, in contrast with esotropic patients. The exact nature of this trend, and possible aetiological factors will require further study.

Polypoidal choroidal vasculopathy in Chinese patients.

AIMS: To report the clinical features and outcomes of polypoidal choroidal vasculopathy (PCV) in Chinese patients with or without laser treatment. METHODS: A consecutive series of 204 indocyanine green angiographies (ICGA) performed for patients with a provisional diagnosis of age related macular degeneration were reviewed retrospectively. Inclusion criteria were ICGA with angiographic features of PCV and patients of Chinese ethnic origin. Medical records were then reviewed and patients were recalled for further assessments. RESULTS: 22 eyes of 19 patients (9.3%) were included. The mean follow up period was 27.4 months (range 4-60 months). The mean age of patients at presentation was 65.1 years (range 51-77 years). The commonest clinical feature at presentation was subretinal haemorrhage (63.6%), followed by retinal exudation (59.1%) and haemorrhagic pigment epithelial detachment (59.1%). There was a predominance of males (68.4%), unilaterality (84.2%), and macular location of polyps (63.6%). Nine eyes received laser photocoagulation. The median initial visual acuity for both the laser and non-laser groups was 6/18. Stable or improved vision was attained in 56% and 31% of laser and non-laser groups, respectively (Fisher's exact test, p=0.38). Mean loss of Snellen lines was 3.1 and 1.1 for the two groups, respectively (two sample t test, p=0.31). At the last follow up, 15 (68.2%) eyes had poor visual acuity of 6/60 or worse, mostly attributed to disciform scar or exudative maculopathy. CONCLUSIONS: There is a predominance of males, unilaterality, and macular location of polyps in Chinese patients with PCV. The overall visual prognosis is guarded regardless of treatment. There is a large amount of variation in the natural course of PCV among different ethnic groups.

Ophthalmopathy in childhood Graves' disease.

AIMS: To study the ocular manifestations and their severity in children with Graves' disease. METHODS: All patients with Graves' disease having regular follow up in a paediatric endocrine clinic were recruited for the study. A comprehensive ophthalmic assessment including ocular motility, exophthalmometry, intraocular pressure (IOP), slit lamp, and fundus examinations was performed. RESULTS: 83 patients (72 female, 11 male) aged 16 years or below were examined. All are Chinese. Ocular symptoms occurred in 12 patients. Ocular signs of ophthalmopathy were documented in 52 patients (62.7%). Most of them presented with eyelid abnormalities such as lid oedema, lid lag, and lagophthalmos, whereas lower lid retraction was the commonest clinical sign noted (38.6%). Diffuse conjunctival injection was found in four patients (4.8%). 10 patients (12.0%) had mild proptosis of less than 3 mm. Only one patient (1.2%) had limited extraocular motility in extreme gaze. Punctate epithelial corneal erosions were reported in 11 patients (13.3%). CONCLUSIONS: This is the largest series on the ocular complications of childhood Graves' disease in the literature. Although 52 patients (62.7%) were identified with positive ocular changes, none of them had visual threatening complications or debilitating myopathy.

Efficacy of lignocaine 2% gel in chalazion surgery.

BACKGROUND/AIMS: To determine whether topical 2% lignocaine (lidocaine) gel is an effective anaesthetic agent for chalazion surgery. METHODS: In a randomised controlled clinical trial, 57 subjects aged 12 years or over requiring incision and curettage for chalazion were recruited over an 8 month period. Patients were randomised into two groups. One group received 1.5 ml of lignocaine 2% injection and the other 1.5 ml of lignocaine 2% gel topically. Standard incision and curettage was then performed. The primary outcome of interest was the total pain experienced during the entire procedure including anaesthetic administration as well as incision and curettage. The pain from the local anaesthetic administration and during incision and curettage was assessed independently using a visual analogue scale (0-100). The sum of these two scores would be the total pain score out of 200. "Fear of injection" score (0-100) was also assessed. RESULTS: There was a statistically significant difference in the mean total pain scores between the injection and the gel groups (95.6 v 57.0) (p <0.001) (alpha = 0.05) (1 - beta = 0.9394). There was a statistically significant difference in the mean scores on "pain of anaesthetic administration" (47.0 v 5.5) (p <0.000). There was no statistically significant differences in the mean scores on "fear of injection" (43.9 v 47.7) (p = 0.668) and "pain during incision and curettage" (48.28 v 51.4) (p=0.679). CONCLUSIONS: Lignocaine 2% gel is effective in chalazion surgery especially in lowering the pain caused by anaesthetic administration.