The Toxic and Stress Responses of Cultured Human Retinal Pigment Epithelium (ARPE19) and Human Glial Cells (SVG) in the Presence of Triamcinolone

PURPOSE

To compare the cytotoxic effect of TA on human retinal pigment epithelium (ARPE19) and human glial (SVG) cells over a range of concentrations and durations of exposure.

METHODS

TA (0.01-1 mg/mL) or vehicle (benzyl alcohol, 0.025%) was added to the ARPE19 and SVG cultures on day 0 and then subsequently for 1, 3, or 5 days. The amount of cell proliferations with or without TA treatment was performed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. All samples were read in triplicate (n = 4 in all cases). c-Fos, c-jun, caspase-3, c-myc, and p53 expression was determined after TA treatments after 0, 10, 20, 30, 40, 50, 60, and 90 minutes. All results were analyzed with ANOVA.

RESULTS

TA (0.01-1 mg/mL) caused a significant reduction in ARPE19 cells that had been exposed to it for more than 1 day. Significant reductions in the number of SVG cells were observed as early as day 1 at 0.1 and 1 mg/mL TA. In general, the level of remaining SVG cells was less than that of the APRE19 cells over the 5 days. SVG cells appeared more susceptible to TA. Caspase-3 was elevated in both ARPE19 and SVG cells after TA treatment. c-Fos and c-jun expression was also increased in ARPE19 cells but not in SVG. The vehicle of TA had no effect, and there was no change in p53 or c-myc expression.

CONCLUSIONS

TA was cytotoxic to both SVG and ARPE19 cells, with higher efficacy on SVG. TA caused the activation of the caspase-3 pathway more readily than the cell-protective c-fos and c-jun pathways in SVG cells, making those cells more vulnerable than the ARPE19 cells. The results suggest that TA toxicity in one cell type may not reliably indicate its toxicity in other cells. Different cells within the retina may react to TA differently, or TA may cause changes in the gene expressions differentially with different concentrations of the same stimulus.

Ocular-Hypertensive and Anti-inflammatory Response to Rimexolone Therapy in Children

OBJECTIVE

To compare the ocular-hypertensive and anti-inflammatory response to rimexolone (116-hydroxy-16alphafluoro-6alphamethylpresdnisolone) and fluorometholone (21-deoxy-9alphafluoro-6alphamethylprednisolone) therapy in children's eyes.

METHODS

With parental consent, children who underwent surgical procedures for bilateral symmetric strabismus from January 18, 2000, through November 16, 2001, were recruited. One eye was randomized to receive topical 1% rimexolone while the contralateral eye received topical 0.1% fluorometholone, 4 times daily for 4 weeks.

MAIN OUTCOME MEASURES

Intraocular pressures and anti-inflammatory responses were the main outcome measures and were serially measured postoperatively for 8 weeks.

RESULTS

Fifty-four children, aged from 4 to 8 years (mean [SD] age, 5.33 [1.26] years), participated in the study. Intraocular pressure increased significantly in both treatment groups compared with the preoperative values (P<.001). The mean (SD) peak intraocular pressure was significantly higher in the rimexolone-treated group, 19.7 (6.1) vs 17.6 (4.6) mm Hg (P<.001). Similarly, the mean (SD) net increase in intraocular pressure (P<.001), was also higher in the rimexolone-treated eyes, 5.9 (4.4) vs 3.9 (4.1) mm Hg (P<.001). In addition, a greater percentage of the rimexolone-treated patients had no conjunctival erythema on days 13 (11.1% vs 0.0%) and 20 (88.9% vs 55.6%) (P =.03).

CONCLUSIONS

Rimexolone seems to be a more effective anti-inflammatory agent than fluorometholone. However, unlike adults, the ocular-hypertensive effect in children treated with rimexolone was higher. It would be desirable to monitor the intraocular pressure regularly when rimexolone therapy is used in children.

Treatment of choroidal neovascularization in central serous chorioretinopathy by photodynamic therapy with verteporfin

PURPOSE

To evaluate the safety and efficacy of photodynamic therapy (PDT) with verteporfin in the treatment of patients with choroidal neovascularization (CNV) secondary to central serous chorioretinopathy (CSC).

DESIGN

Open-label, two-center, noncomparative, prospective interventional case series.

METHODS

Consecutive patients with subfoveal or juxtafoveal CNV secondary to CSC were recruited and treated with a standard regimen of PDT with verteporfin. At regular 3-month follow-up examinations, re-treatment was considered if fluorescein angiography showed evidence of leakage. Outcome measures included the proportion of patients who had improvement (gained 2 more lines), stable, or loss (dropped in 2 or more lines) in vision at the final follow-up and the changes in best-corrected visual acuity (BCVA) from baseline.

RESULTS

Ten eyes of 10 patients were recruited into the study. The mean age of the patients was 57.3 years with a mean follow-up duration of 12.6 months. At the last follow-up, six (60%) eyes gained 2 or more lines of BCVA with four (40%) patients having final BCVA of within 1 line. No patient lost 2 or more lines of BCVA. The mean logarithm of the minimal angle of resolution BCVA improvement after PDT was 2.4 lines (Wilcoxon signed-rank test, P =.013). No patient suffered serious ocular or systemic complications from PDT.

CONCLUSIONS

Photodynamic therapy with verteporfin therapy is a safe and well-tolerated treatment in patients with CNV associated with CSC. A randomized, controlled trial with a longer follow-up period is warranted to further study the efficacy of PDT in the management of CNV secondary to CSC.

Topical mydriatic and cycloplegic spray for Chinese children

PURPOSE

To assess the efficacy and tolerance of mydriatic and cycloplegic spray versus drops for Chinese children.

METHODS

The effects of the spray (cyclopentolate 0.25%, phenylephrine 0.625%, and tropicamide 0.5%) and the drops (cyclopentolate 1%, phenylephrine 0.5%, and tropicamide 0.5%) were evaluated in 29 children (58 eyes) in two separate sessions. There was a 1-week period between the applications of the spray and the drops. Dilated pupil size and refraction after cycloplegia were the primary outcome variables used to assess the efficacy. A subjective discomfort score was used to assess acceptance of the spray and the drops.

RESULTS

The mean age of the study population was 4.33 +/- 1.39 years (range, 3 to 8 years). The mean pupil size was 6.9 mm for the spray and 6.6 mm for the drops. The spray appeared to be slightly more effective than the drops, with a mean difference of 0.3 mm that was statistically significant (P = .001, two-tailed t test). No statistically significant difference in cycloplegic response was found between the spray and the drops (P = .535, two-tailed t test). Administration of the spray caused less discomfort than did administration of the drops (P < .001, Wilcoxon signed-rank test).

CONCLUSIONS

The spray system appears to be clinically equivalent to the drops for achieving effective pupil dilation and cycloplegia, even in a population with dark irides such as ours. Tolerability and acceptance improved because the spray was applied to the closed eyelids.

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.

Different optineurin mutation pattern in primary open-angle glaucoma

PURPOSE

The optineurin gene (OPTN) is the second gene besides MYOC in which mutations have been identified to be associated with primary open-angle glaucoma (POAG). In this study, sequence alterations in the OPTN gene associated with POAG in Chinese subjects were investigated.

METHODS

All the coding exons of OPTN were screened, including the intron-exon boundaries, for sequence alterations in a Chinese sample of 119 sporadic patients with POAG and 126 unrelated control subjects by polymerase chain reaction-conformation-sensitive gel electrophoresis and DNA sequencing.

RESULTS

Sixteen sequence changes were identified: 3 had been reported (T34T, M98K, and R545Q) and 13 were novel (T49T, E103D, V148V, P199P, T202T, H486R, IVS6-5T-->C, IVS6-10G-->A, IVS7+24G-->A, IVS8+20G-->A, IVS13+21C-->G, IVS15+10G-->A, and IVS15-48C-->A). Among them, only E103D, H486R, V148V, and IVS13+21C-->G were found exclusively in patients with POAG, whereas P199P, T202T, and IVS8+20G-->A were present only in control subjects. The genotype of IVS7+24G-->A showed a significant association with POAG (P = 0.02, Fisher two-tailed exact test) and with and increased cup-to-disc ratio in these patients (P = 0.005, Mann-Whitney test).

CONCLUSIONS

The findings in the current study enrich the evidence on the OPTN gene as a causative gene for POAG and suggest a different mutation pattern of OPTN in Chinese than in whites. The wide spectrum of putative mutations detected in this study suggests that both structural and functional disruptions in OPTN may contribute to the pathogenesis of glaucoma.

Trabeculectomy with beta radiation: long-term follow-up

PURPOSE

To evaluate the long-term outcome and complications of trabeculectomy with beta radiation.

DESIGN

Retrospective noncomparative case series.

PARTICIPANTS

Forty-three patients with confirmed primary open-angle glaucoma (POAG), who received trabeculectomy with adjunctive beta radiation at the Prince of Wales Hospital between June 1991 and November 1994.

METHODS

Patients fulfilling the preceding criteria were followed up longitudinally. The visual acuity, intraocular pressure (IOP), bleb morphology, and complications were evaluated.

MAIN OUTCOME MEASURES

Visual acuity, IOP, bleb morphology, complications.

RESULTS

Forty-three eyes of 43 consecutive Chinese patients were recruited and successfully followed up for a minimum of 7 years. The mean age +/- 1 standard deviation (SD) was 60.9 +/- 13.0 years. There were 29 males and 14 females. The mean baseline IOP +/- 1 SD was 28.3 +/- 5.8 mmHg. The mean postoperative IOP +/- 1 SD after the initial trabeculectomy was 11.9 +/- 4.3 mmHg, and the mean number of preoperative IOP-lowering eyedrops +/- 1 SD was reduced from 2.8 +/- 0.5 to 0.7 +/- 1.0 at 7 years follow-up. The qualified success rate at 7 years follow-up, defined as IOP <or=21 mmHg with and without medication(s), was 88.4%. The complete success rate at 7 years defined as IOP <or=21 mmHg without medication was 60.7%. Two eyes developed blebitis, and one of them progressed to corneal decompensation after the infection. One eye had hypotony, and one eye had a traumatic ruptured bleb. Twelve eyes (27.9%) developed significant cataract. No corneal ulceration or scleral necrosis was encountered.

CONCLUSIONS

From this noncomparative study, trabeculectomy with a single dose of 1000 rad beta radiation used as an adjunctive measure for POAG in Chinese eyes had achieved a qualified success rate of 88.4% at 7 years.

Photodynamic therapy with verteporfin in laser-induced choroidal neovascularization

PURPOSE

To report a case of laser-induced choroidal neovascularization (CNV) treated with verteporfin photodynamic therapy.

DESIGN

Interventional case report.

METHODS

A patient developed CNV in the macular area of the left eye 2 years following grid laser for macular edema secondary to branch retinal vein occlusion.

RESULTS

The CNV was controlled with one session of photodynamic therapy. Lesion decreased in size, contracting to a smaller subretinal fibrotic scar. Vision improved from 20/200 to 20/100, and there was no recurrence at 2-year follow-up. No complications were encountered.

CONCLUSION

Laser-induced CNV can be safely and effectively treated by photodynamic therapy.

Infective endophthalmitis caused by Bacillus cereus after cataract extraction surgery

We describe a 72-year-old Chinese man who developed fulminant Bacillus cereus endophthalmitis 36 h after an uneventful surgery for cataract extraction. Clinical progression of disease was extremely rapid, in spite of early vitrectomy and intravitreal injection of antibiotics. Results of Gram staining showed gram-positive bacilli, and the culture was positive for B. cereus. Endophthalmitis is rare after cataract surgery (cumulative probability within 1 year, approximately 0.08%), and cases caused by B. cereus are even less common. The prognosis and plan of treatment are discussed.

Diode laser transscleral cyclophotocoagulation in the treatment of chronic angle-closure glaucoma: a preliminary study

PURPOSE

To evaluate the efficacy and safety of diode laser transscleral cyclophotocoagulation in the treatment of chronic angle-closure glaucoma.

PATIENTS AND METHODS

A prospective, non-comparative interventional pilot study was conducted. Fourteen eyes of 14 Chinese patients with chronic angle-closure glaucoma whose intraocular pressures were greater than 21 mm Hg on medications were treated with diode laser transscleral cyclophotocoagulation using the G-probe at the United Christian Hospital between February 2000 and May 2001. The inferior 270 degrees quadrant (from 2 to 11 o'clock for right eye and from 1 to 10 o'clock for left eye) was treated and the patients were followed up regularly. The initial laser energy was set at 2,000 mWatt with a duration of 2 seconds. The post-treatment anti-glaucoma medications were adjusted according to the intraocular pressure. If medications failed to lower the intraocular pressure to below 21 mm Hg, cyclophotocoagulation to the same inferior 270 degrees quadrant was repeated.

RESULTS

All patients completed a 12-month follow-up period. The total success rate defined as IOP < 21 mm Hg with or without medication(s) was 85.7% at 1 year of follow-up review. The mean +/- SD intraocular pressure decreased from pre-treatment level of 36.9 +/- 11.7 mm Hg to 18.9 +/- 6.5 mm Hg at 1 year after treatment. The difference was statistically significant (P < 0.001) (Paired t test). The mean +/- SD number of IOP-lowering eyedrops was significantly reduced from 1.9 +/- 0.7 before cyclophotocoagulation to 0.4 +/- 0.8 at 1 year after treatment (P = 0.0002) (Paired t test). Two eyes required repeat treatment. Seven eyes (50%) had atonic pupil following the laser treatment.

CONCLUSION

Diode laser transscleral cyclophotocoagulation is effective in lowering the intraocular pressure in chronic angle-closure glaucoma and its effect lasts for at least 1 year.

Isolated microspherophakia with optic disc colobomata

We describe a case of isolated bilateral microspherophakia with optic disc colobomata. A satisfactory outcome was achieved following uneventful lensectomy and scleral fixation of an intraocular lens.

Comparison of lidocaine 2% gel versus amethocaine as the sole anesthetic agent for strabismus surgery

PURPOSE

To compare the efficacy of lidocaine 2% gel with amethocaine 1% eyedrops as the sole anesthetic agent for one-stage adjustable suture strabismus surgery.

DESIGN

Prospective, double-masked randomized trial.

PARTICIPANTS

Fourteen consecutive patients scheduled to undergo bilateral and symmetrical strabismus surgery under topical anesthesia in one institution.

METHODS

Each patient was randomized to receive lidocaine 2% gel in one eye and amethocaine 1% eyedrops in the other eye as the sole anesthetic agent for surgery. Masking of the patient and surgeon was ensured by administration of a placebo gel and eyedrop as part of the regimen. Pain and discomfort were assessed via a 10-cm visual analog scale.

MAIN OUTCOME MEASURES

Subjective pain and discomfort perceived during surgery were assessed separately by the patient and the surgeon, and the need for any additional anesthesia was recorded.

RESULTS

A total of 14 subjects indicated mean pain and discomfort scores of 2.6 and 3.2 respectively, for lidocaine gel, and 5.3 and 6.2, respectively, for amethocaine drops (P = 0.01). The mean number of additional drops required by eyes randomized to lidocaine gel was 0.3, compared with 1.6 for amethocaine drops (P = 0.02).

CONCLUSIONS

In terms of pain control, lidocaine 2% gel alone is a superior topical anesthetic for one-stage adjustable suture strabismus surgery when compared with amethocaine 1% eyedrops.

Combined phacoemulsification, pars plana vitrectomy, and foldable intraocular lens implantation

We describe a technique for combined cataract and vitreoretinal surgery using sutureless sclerocorneal and sclerotomy incisions and a foldable intraocular lens. This technique, with its variations for cases with and without gas-fluid exchange, was successfully performed in 40 consecutive cases over a 5-month period. No significant complications related to the surgical procedures were encountered. The rationale and advantages of this technique are discussed.

Orthokeratology lens-related Pseudomonas aeruginosa infectious keratitis

PURPOSE

To report a case of orthokeratology lens-related Pseudomonas corneal ulcer in an adult.

METHODS

Case report.

RESULTS

A 37-year-old man presented with a 1-day history of painful red eye. He was a soft contact lens wearer before he started on nocturnal orthokeratology lens wear of 8 to 10 hours per night 9 months ago. Corneal scraping sent for culture revealed a heavy growth of Pseudomonas aeruginosa. The patient was treated with intensive topical fortified tobramycin and ceftazidime drops. The ulcer healed with a residual paraxial corneal scar. Although his best-corrected visual acuity (BCVA) recovered from finger counting (8/200) at presentation to 20/30, he suffered visual loss from a premorbid BSCVA of 20/15. His contrast sensitivity (Vector Vision CSV 1000 test) performance was also worse than his fellow eye.

CONCLUSION

Nocturnal orthokeratology lens wear may be associated with an increased risk of infection.

Fornix-based trabeculectomy using the 'anchoring' corneal suture technique

AIM

To assess the safety and efficacy of fornix-based tra-beculectomy with the 'anchoring' corneal suture technique in Chinese patients.

METHODS

A retrospective non-comparative case series of 66 eyes of 63 Chinese patients who underwent fornix-based trabeculectomy combined with intraoperative mitomycin C (MMC) 0.4 mg/mL for 2-5 min were studied. Conjunctival wound closure of all eyes was with the anchoring corneal suture technique using a 9-0 nylon suture to prevent leakage at the corneolimbal interface. The success rate, with or without anti-glaucoma medication, the complication rate and the longevity of the drainage blebs were analyzed.

RESULTS

At a mean follow-up period of 447.36 +/- 337.98 days, the mean intraocular pressure decreased from 26.83 +/- 7.90 mmHg to 17.74 +/- 8.74 mmHg (P < 0.001). The mean glaucoma medication decreased from 2.95 +/- 0.98 preoperatively to 1.23 +/- 1.41 postoperatively (P < 0.001). Thirty-one eyes (47.0%) required no anti-glaucoma medication postoperatively. Twenty eyes (30.3%) had qualified success postoperatively. Eight eyes (12.1%) had early wound leakage that resolved with conservative treatment. Three eyes (4.5%) required surgical repair. One eye (1.5%) had hypotonous maculopathy. No other major complications were encountered.

CONCLUSION

Fornix-based trabeculectomy with adjunctive mitomycin C employing the anchoring corneal suture technique appears to be both safe and effective in Chinese patients.

Familial high myopia linkage to chromosome 18p

A locus for autosomal dominant high myopia was reported on chromosome 18p. We sought to confirm this finding and narrow the reported interval by analyzing high myopia among families of Hong Kong Chinese, in whom myopia is common. In 15 families with a possibly autosomal dominant inheritance of high myopia (>or=-6 dpt) in at least 2 generations, 10 chromosome 18p markers were analyzed for linkage with high myopia. Two-point linkage analysis showed trends toward linkage of markers D18S476 and D18S62 with high myopia, with maximum logarithm of odds (LOD) scores of at least 1.1 and 1.7, respectively. Multipoint analysis of those 2 markers gave a maximum LOD score of at least 2.1. To attempt to account for likely genetic heterogeneity, 5 families showing evidence of linkage of the 2 markers with high myopia were selected for further multipoint linkage analysis, resulting in a maximum LOD score of 2.4 at D18S476. While multiple genetic and environmental factors likely contribute to myopia, these data are consistent with the possibility of a locus on chromosome 18p.

ABCA4 sequence variants in Chinese patients with age-related macular degeneration or Stargardt's disease

ABCA4 gene sequence alterations cause Stargardt's disease (STGD) and may cause some age-related macular degeneration (AMD). We sought to shed light on these associations among Hong Kong Chinese by genotyping 140 AMD, 18 STGD and 95 normal control subjects for 15 ABCA4 exons which were reported to often contain AMD- or STGD-associated mutations. Sequence alterations R212H, T1428M, V1433I, T1572M, I2166M, IVS6-5T>G and IVS33+1G>T were found in AMD patients. T1428M and R2040X occurred in STGD patients. Control subjects displayed all the above missense alterations but no splicing or nonsense changes. Therefore, ABCA4 splicing mutations may be associated with a small proportion of AMD cases.

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.

Randomized clinical trial of the efficacy and safety of tropicamide and phenylephrine in preoperative mydriasis for phacoemulsification

PURPOSE

To compare the mydriatic effect and safety between different concentrations of tropicamide and phenyle-phrine in preoperative mydriasis for phaco-emulsification.

METHODS

Two hundred and seventeen consecutive eyes in the same number of Chinese patients undergoing phaco-emulsification under local or topical anaesthesia in a university-based eye hospital were analyzed. Patients were randomized into two groups by cluster randomization, each group receiving a different preoperative mydriatic regimen. Regimen A consisted of tropicamide 1.0% with phenylephrine 2.5%, and Regimen B consisted of tropicamide 0.5% with phenylephrine 0.5%. The main outcome measures were horizontal pupillary diameter, systolic, diastolic and pulse pressure and pulse rate.

RESULTS

The group who received Regimen A attained a mean horizontal pupillary diameter of 7.00 +/- 1.06 mm. Their pupils were significantly larger than those receiving Regimen B (6.61 +/- 1.03 mm, P = 0.007). No untoward cardiovascular effects were noted in either groups.

CONCLUSION

Regimen A attained better preoperative mydriasis for phacoemulsification than Regimen B. Both regimens were safe with regard to their cardiovascular effects. The combination of tropicamide 1.0% and phenylephrine 2.5% is recommended as preoperative mydriatic for phacoemulsification in Chinese patients who have darkly pigmented irides.

In vivo confocal microscopy of corneal insect foreign body

PURPOSE

To report a case of insect corneal foreign body with in vivo confocal microscopy performed.

METHODS

Clinical presentation, clinical pictures, and treatment are discussed. Confocal microscopy of the injured cornea was performed in areas showing foreign bodies with and without infiltrations seen under the slit-lamp.

CONCLUSION

Confocal microscopy is useful in detection of subtle inflammatory reaction, monitoring the progress of the injury and decision of treatment plans.

Pars plana vitrectomy in the management of retained intravitreal lens fragments after cataract surgery

PURPOSE

To assess the outcome of patients who underwent pars plana vitrectomy for retained lens fragments after cataract surgery.

METHODS

A retrospective study of all consecutive cases with pars plana vitrectomy performed for retained lens fragment was conducted. Twenty-seven eyes of 27 patients were included in the study.

RESULTS

Twenty-four (89.9%) eyes received phacoemulsification. Pars plana vitrectomy was performed at the same sitting, or ranged from day 1-70 after cataract surgery. The mean follow up was 31.1 months. Final visual acuity of 6/12 or better was achieved in 15 (55.6%) patients. After excluding patients with pre-existing eye diseases, 68.4% of patients had visual acuity 6/12 or better. Complications after pars plana vitrectomy included glaucoma (22.2%), retinal detachment (11.1%) and surgically induced necrotizing scleritis (3.7%).

CONCLUSION

Ocular complications with poor visual outcome can occur after removal of intravitreal retained lens fragments complicating cataract surgery.

Laser peripheral iridoplasty as initial treatment of acute attack of primary angle-closure: a long-term follow-up study

PURPOSE

To study the long-term clinical course and complications of patients with acute primary angle-closure treated with immediate laser peripheral iridoplasty followed by laser peripheral iridotomy.

PATIENTS AND METHODS

Consecutive patients with acute primary angle closure treated with immediate laser peripheral iridoplasty, followed by laser peripheral iridotomy, at the Prince of Wales Hospital from July 1997 through January 2000 were followed up to document the clinical course of their disease and any complications from the laser treatment. Visual acuity, intraocular pressure, gonioscopic findings, corneal and lens clarity, iris appearance, pupillary reaction, and progression of glaucomatous optic neuropathy were evaluated.

RESULTS

Thirty eyes of 29 Chinese patients with acute primary angle closure treated initially with either argon or diode laser peripheral iridoplasty were recruited. The mean follow-up period was 33.0 +/- 9.3 months. Twenty-one eyes (70%) had no further attack and maintained normal intraocular pressure without medications, and 9 eyes (30%) developed chronic angle-closure glaucoma with peripheral anterior synechiae. All eyes had pigmented laser marks on the peripheral iris, but none had peripheral corneal burn.

CONCLUSIONS

Long-term follow-up data indicated that 30% of Chinese eyes with acute primary angle closure successfully treated with immediate laser peripheral iridoplasty followed by laser peripheral iridotomy developed peripheral anterior synechiae and an increase in intraocular pressure. There were minimal long-term complications on the cornea and the lens from the laser treatment.

Loss of heterozygosity and mutations are the major mechanisms of RB1 gene inactivation in Chinese with sporadic retinoblastoma

We investigated sequence alternation, promoter methylation, and loss of heterozygosity (LOH) of the RB1 gene as possible mechanisms of its inactivation in retinoblastoma. In 42 Chinese patients with sporadic retinoblastoma, the promoter and entire coding region of RB1 were examined for sequence changes. Status of methylation of the CpG-rich island at the 5'end was determined by methylation specific PCR assay. We detected 15 RB1 mutations in 38% (16/42) of the retinoblastoma patients, among them 19% (8/42) were germ-line mutations. A total of nine novel mutations were identified: E54X, S114X, I126S, g73779insG, D718N, IVS2+1G>C, IVS14+1G>C, IVS21+1G>C, and a complex alteration g78177G>T/g78176insTT leading to 543X. Most of them are likely to affect the RB1large pocket domain through the production of truncated gene products. None of the DNA samples showed methylation at the RB1promoter. In 15 cases where both normal and cancerous retinoblastoma tissue specimens were available, allelic loss according to microsatellite markers within or distal to the RB1 locus was analyzed and immunohistological staining for RB1 expression performed. Among them, frequency of LOH at 13q14 was found to be high at 60% (9/15) with no segregation with unilateral tumors. All these nine tumors did not express RB1 protein, showing an association of LOH at the RB1 locus with its loss of expression in retinoblastoma. Our results indicate that the RB1 gene in sporadic retinoblastoma is commonly inactivated because of loss-of-function mutations and loss of heterozygosity but not by the epigenetic phenomenon of promoter hypermethylation.

Nausea and vomiting after phacoemulsification using topical or retrobulbar anesthesia

PURPOSE

To determine and compare the incidence of postoperative nausea and vomiting in patients having phacoemulsification under topical or retrobulbar anesthesia.

SETTING

Department of Ophthalmology, United Christian Hospital, Hong Kong, China.

METHODS

In this prospective randomized clinical trial, patients scheduled for routine phacoemulsification with posterior chamber intraocular lens implantation under local anesthesia without sedation were randomized to receive topical anesthesia or retrobulbar anesthesia. One hundred seven eyes of 107 Chinese patients were included. There were 49 patients and 58 patients of similar age and sex distribution in the retrobulbar group and topical group, respectively. Postoperative nausea and vomiting (PONV), the need for an antiemetic, and intraocular pressure (IOP) were recorded 1 day after surgery. Also recorded were the patient's preexisting risk factors for PONV (if any), fasting time, duration of surgery, and intraoperative complications or need for supplementary anesthesia or analgesia.

RESULTS

The overall incidence of PONV in the entire study group was 3.7% (4 patients). No statistically significant differences in PONV were found between the 2 anesthesia techniques, although 6.1% (3 of 49) in the topical group had nausea compared with 1.7% (1 of 58) in the retrobulbar group. No significant differences were found in the fasting time, duration of surgery, or postoperative IOP between patients who had PONV and those who did not.

CONCLUSIONS

Topical and retrobulbar anesthesia were associated with a low incidence of PONV in routine phacoemulsification. There were no statistically significant differences in PONV between the 2 anesthesia techniques. No significant correlation was found between the incidence of PONV and the duration of surgery, presence of complications, fasting time, postoperative IOP, or history of PONV or motion sickness.

The use of postoperative topical mitomycin C in the treatment of recurrent conjunctival papilloma

PURPOSE

To describe the use of postoperative topical mitomycin C (MMC) in the treatment of recurrent conjunctival papilloma.

METHODS

Case report.

RESULTS

We report a 26-year-old man with recurrent conjunctival papilloma despite repeated surgical excision, cauterization, and cryotherapy. He was then treated with excision by cryotherapy, followed by a 2-week course of topical MMC eyedrops prescribed at postoperative day 7 (0.02 mg/mL, four times daily). No recurrence was observed 24 months postoperatively, and no complication was observed during the follow-up period.

CONCLUSION

Postoperative topical MMC may be a useful adjunct in the management of recurrent conjunctival papilloma.

Descemet membrane detachment after sequential argon-neodymium:YAG laser peripheral iridotomy

PURPOSE

To report a case of Descemet membrane detachment after sequential argon-neodymium (Nd):yttrium-aluminum-garnet (YAG) laser peripheral iridotomy.

DESIGN

Interventional case report.

METHODS

A 72-year-old Chinese man presented with acute primary angle-closure in the left eye. In the fellow right eye, a localized Descemet membrane detachment developed after prophylactic sequential argon-Nd:YAG laser peripheral iridotomy. Ultrasound biomicroscopy pictures were taken.

RESULTS

The Descemet membrane detachment reattached gradually without intervention. The cornea remained clear and the vision was unchanged.

CONCLUSION

In sequential argon-Nd:YAG laser peripheral iridotomy, the shock wave formed during photodisruption may produce linear cracks at the level of Descemet membrane, resulting in detachment. This complication can occur irrespective of the color of the iris.

TIGR/MYOC gene sequence alterations in individuals with and without primary open-angle glaucoma

PURPOSE

To discover sequence alterations in the TIGR/MYOC gene associated with primary open-angle glaucoma (POAG) in Chinese subjects.

METHODS

Two hundred one unrelated Chinese patients with POAG and 291 unrelated individuals without glaucoma, aged 50 years or more, were screened for sequence alterations in the TIGR/MYOC gene by polymerase chain reaction, conformation sensitive gel electrophoresis, and DNA sequencing. Up to 111 more control subjects were screened for some of the alterations.

RESULTS

Fourteen sequence variants that lead to amino acid changes were identified. Seven were novel: Pro16Leu, Ala17Ser, Leu95Pro, Leu215Pro, Glu300Lys, Glu414Lys, and Tyr471Cys. Of these, Glu300Lys and Tyr471Cys were found only in POAG. Arg46Stop was found in 4 patients with POAG (2.0%) and 9 of 402 control subjects (2.2%); one control subject was homozygous. IOP showed a trend (P = 0.11) toward a decrease of 1.5 mm Hg among the control subjects, with Arg46Stop compared with matched control subjects without Arg46Stop. Gly12Arg occurred four times as frequently in control subjects as in patients, but the difference was not statistically significant.

CONCLUSIONS

Gly12Arg might be negatively associated with POAG, suggesting a protective effect. Three patients with POAG had a sequence change not found in control subjects, for a frequency of possible disease-causing TIGR/MYOC mutations of 1.5% (95% confidence interval [CI] = 0.3%-4.3%). Arg46Stop occurred with similar frequency in patients with POAG and control subjects, suggesting that the reduced amount of TIGR/MYOC predicted to result from this truncation does not dramatically increase or decrease risk of glaucoma.

Outcomes of implantation of an artificial cornea, AlphaCor: effects of prior ocular herpes simplex infection

PURPOSE

To review outcomes of AlphaCor artificial cornea implantation in patients with and without a history of ocular herpes simplex virus (HSV) and to determine whether herpetic eye disease is an indication for AlphaCor surgery.

METHODS

Outcomes of the initial 40 implantations were reviewed and stratified by the presence of a history of ocular disease caused by HSV. Outcomes measures (complications, visual acuity gained) were compared.

RESULTS

Eight of the 40 AlphaCor implantations (20%) were in patients with a history of ocular HSV. Six of these eight patients (75%) developed melt-related complications after AlphaCor insertion. Half of the affected patients required removal of the AlphaCor and replacement with a donor corneal graft to restore ocular integrity. In comparison, only six of the 32 (18.8%) patients without HSV developed a melt after AlphaCor insertion. Patients with HSV with devices in situ exhibited a mean loss of 0.3 line of best-corrected visual acuity compared with the preoperative visual acuity, whereas patients without HSV exhibited a mean gain of 1.4 lines of best-corrected visual acuity.

CONCLUSIONS

The extensive lamellar corneal surgery involved in AlphaCor implantation may precipitate reactivation of latent HSV such that reactivation and resultant inflammation reduce device biointegration and facilitate melting of corneal stromal tissue anterior to the device. Although there may be some benefit from systemic antiviral medication, the current series is not large enough to demonstrate such a benefit, and melting can occur despite medication. The statistically significant difference in outcomes between recipients of AlphaCor with and without HSV is evidence that a history of HSV should be an exclusion factor for AlphaCor surgery.

Intracameral lidocaine in trabeculectomy. A preliminary safety and efficacy study

PURPOSE

To study the safety and efficacy of intracameral lidocaine as anaesthesia in trabeculectomy for primary open-angle glaucoma.

METHODS

Trabeculectomy under intracameral anaesthesia using 1% preservative-free lidocaine was performed in 10 patients with primary open-angle glaucoma. Intraoperative pain score, postoperative intraocular pressure (IOP) and endothelial cell count at 3 months were recorded.

RESULTS

The mean pain score was 1.70 +/- 1.34. The mean IOP was lowered from 24.60 +/- 8.28 mmHg preoperatively to 14.1 +/- 3.11 mm Hg postoperatively. There was no significant decrease in the mean endothelial cell count 3 months after the surgery (P = 0.375).

CONCLUSION

Intracameral lidocaine may be a safe and effective alternative anaesthesia method in trabeculectomy for uncomplicated primary open-angle glaucoma.

Incidence and risk factors for microbial keratitis in Hong Kong: comparison with Europe and North America

PURPOSE

To establish the incidence, etiology and risk factors for microbial keratitis (MK) in Hong Kong.

METHODS

Two hundred and twenty-three new cases of presumed MK were recruited over a period of 17 months and comprehensive microbiologic studies performed. A nested case-control study was pursued for patients wearing contact lenses (CLW) to determine risk factors for MK with regards to types of CLW and hygiene practice.

RESULTS

Of the 223 patients recruited, 59 (26%) wore contact lenses. Corneal scrapes yielded positive cultures from 77 patients (35% overall, 56 non-CLW, 21 CLW). Two hundred and six CLW volunteers were recruited to participate in the case-control study, of whom 135 were matched with 45 CLW patients. The annual incidence of MK was 0.63 per 10,000 population and 3.4 per 10,000 CLW with rates for daily, extended and rigid lens wear of 3.09, 9.30 and 0.44 per 10,000 CLW respectively. Pseudomonas aeruginosa was the dominant bacterial pathogen. Six cases of Acanthamoeba keratitis occurred, five in CLW (incidence 0.33 per 10,000 CLW) and one following corneal abrasion. Non-CLW developed MK at a peak age of 73, which is 10 years younger than expected for Scotland and USA.

CONCLUSIONS

Previous ocular surface disease and trauma were the main risk factors for MK in Hong Kong. CLW appears at least as safe as that found in Scotland and the USA. Acanthamoeba keratitis was detected but with an incidence rate five times lower than Scotland. Factors predisposing hydrogel CLWs to MK, that were statistically significant, included overnight wear, poor hygiene and smoking.

Argon laser peripheral iridoplasty versus conventional systemic medical therapy in treatment of acute primary angle-closure glaucoma : a prospective, randomized, controlled trial

OBJECTIVE

To study whether argon laser peripheral iridoplasty (ALPI) is as effective and safe as conventional systemic medications in treatment of acute primary angle-closure glaucoma (PACG) when immediate laser peripheral iridotomy is neither possible nor safe.

DESIGN

Prospective, randomized, controlled trial.

PARTICIPANTS

Seventy-three eyes of 64 consecutive patients with their first presentation of acute PACG, with intraocular pressure (IOP) levels of 40 mmHg or more, were recruited into the study.

INTERVENTION

The acute PACG eye of each consenting patient received topical pilocarpine (4%) and topical timolol (0.5%). The patients were then randomized into one of two treatment groups. The ALPI group received immediate ALPI under topical anesthesia. The medical treatment group was given 500 mg of intravenous acetazolamide, followed by oral acetazolamide 250 mg four times daily, and an oral potassium supplement until IOP levels normalized. Intravenous mannitol also was administered to the latter group if the presenting IOP was higher than 60 mmHg. The acute PACG eye of both groups continued to receive topical pilocarpine (1%) until peripheral iridotomy could be performed.

MAIN OUTCOME MEASURES

Intraocular pressure profile, corneal clarity, symptoms, visual acuity, angle status by indentation gonioscopy, and complications of treatment.

RESULTS

Thirty-three acute PACG eyes of 32 patients were randomized to receive immediate ALPI, whereas 40 acute PACG eyes of 32 patients had conventional systemic medical therapy. Both treatment groups were matched for age, duration of attack, and IOP at presentation. The ALPI-treated group had lower IOP levels than the medically treated group at 15 minutes, 30 minutes, and 1 hour after the start of treatment. The differences were statistically significant. The difference in IOP levels became statistically insignificant from 2 hours onward. The duration of attack did not affect the efficacy of ALPI in reducing IOP in acute PACG. No serious laser complications occurred, at least in the early postlaser period.

CONCLUSIONS

Argon laser peripheral iridoplasty significantly is more effective than conventional systemic medications in reducing IOP levels in acute PACG in eyes not suitable for immediate laser peripheral iridotomy within the first 2 hours from the initiation of treatment. Argon laser peripheral iridoplasty is a safe and more effective alternative to conventional systemic medications in the management of acute PACG not amenable to immediate laser peripheral iridotomy.

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.

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.

Graft-vs-host-disease-associated conjunctival chemosis and central serous chorioretinopathy after bone marrow transplant

PURPOSE

To describe bilateral conjunctival chemosis and central serous chorioretinopathy in a patient with graft-vs-host disease after bone marrow transplant.

DESIGN

Interventional case report.

METHODS

A 45-year-old Chinese woman developed blurring of vision 16 days after bone marrow transplant for multiple myeloma. She had graft-vs-host disease 11 days after bone marrow transplantation. On examination, vision was 0.6 in the right eye and 0.3 in the left eye. Bilateral conjunctival chemosis and multiple central serous chorioretinopathy were present.

RESULTS

Treatment of graft-vs-host disease with high-dose systemic corticosteroid and cyclosporin led to the resolution of the conjunctival chemosis and central serous chorioretinopathy 3 months later. Visual acuity improved to 0.8 in both eyes.

CONCLUSION

Choroidal infiltrate in graft-vs-host disease may contribute to choroidal hyperpermeability, which leads to the development of central serous chorioretinopathy in postbone marrow transplant patients.

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.

Argon laser suture lysis using Ritch lens following cataract surgery

Argon laser suture lysis using the Ritch lens provides a safe and effective means for correction of post--ECCE suture--induced astigmatism.

Traumatic subluxation causing variable position of the crystalline lens

We present a case of traumatic lens subluxation that was evident only when the patient was in the supine position. This case illustrates that a crystalline lens with traumatic zonular rupture can change its position depending on the posture of the patient. If such a lens is suspended by the remaining zonules at the superior quadrant while the patient is erect, phacodonesis may be present while the lens remains in its normal position. However, when the patient is in the supine position, the lens drops back into the vitreous cavity. Examination in erect and supine positions is important in the preoperative assessment of patients with traumatic phacodonesis or iridodonesis.

Topical anesthesia in phacotrabeculectomy

PURPOSE

To study the safety and efficacy of topical anesthesia alone, without systemic sedation, in phacotrabeculectomy for cataract and primary open-angle glaucoma.

METHODS

In this prospective study, topical anesthesia with 2% lidocaine hydrochloride jelly without systemic sedation was used for combined phacoemulsification, posterior chamber intraocular lens implantation, and trabeculectomy in consecutive patients with primary open-angle glaucoma and concurrent cataract at the United Christian Hospital, Kowloon, Hong Kong, from September 2000 to May 2001. Visual analog pain score and change in vital signs were used to assess the intraoperative pain experience. Other outcome measures included postoperative visual acuity and intraocular pressure at 3 months.

RESULTS

Twenty-two eyes of 22 consecutive patients were included in the study. The mean intraoperative pain score was 0.9 (range, 0-3). Three patients reported discomfort intraoperatively. No injection of supplementary anesthetic was required in any of the eyes. None of the patients had significant increase of pulse rate or blood pressure during the whole surgical procedure. Six patients required oral analgesic for postoperative discomfort. The mean preoperative medically treated IOP was 20.3 +/- 5.9 mm Hg and the mean postoperative IOP at 3 months was 14.4 +/- 4.7 mm Hg. All except two patients had improved visual acuity. There was no serious intraoperative or postoperative complication.

CONCLUSION

Topical 2% lidocaine hydrochloride jelly without systemic sedation may be a safe and effective anesthetic method in phacotrabeculectomy for patients with primary open-angle glaucoma with coexisting cataract.