Randomized double-masked controlled trial comparing pain scores with and without the use of supplementary 2% lidocaine gel in LASIK.

PURPOSE: To compare pain scores with and without supplementary topical 2% lidocaine gel in patients undergoing simultaneous bilateral laser-assisted in situ keratomileusis (LASIK) under topical anesthesia using 0.5% proparacaine eye drops. DESIGN: Randomized double-masked placebo-controlled trial. METHODS: Fifty-one Chinese subjects (102 eyes, with 51 eyes in each arm) were included. One eye was randomly allocated to have supplementary 2% lidocaine gel while the other eye received carbomer gel as control, in addition to topical 0.5% proparacaine. The pain scores for each eye during microkeratome flap creation, during laser ablation, and at 15, 30, and 45 minutes after LASIK were assessed. An overall pain score of the LASIK procedure was also obtained. Primary outcome measures were pain scores during and after LASIK. Secondary outcomes included need for additional topical anesthesia, patient cooperation score, and duration and complications of surgery. RESULTS: In the 2% lidocaine gel-treated group, the pain scores were significantly lower during microkeratome flap creation and laser ablation, and postoperatively at 30 and 45 minutes (P<.05 for all). Patients in the lidocaine gel group required less additional topical anesthesia (P=.0004) and were more cooperative (P=.019) as compared to the carbomer gel group. No surgical or postoperative complications were observed. CONCLUSIONS: The use of supplementary 2% lidocaine gel in LASIK is effective in lowering the pain experienced during and up to 45 minutes after LASIK.

Analysis of the posterior polymorphous corneal dystrophy 3 gene, TCF8, in late-onset Fuchs endothelial corneal dystrophy.

PURPOSE: Because the endothelial (posterior) corneal dystrophies share common pathologic features and result from primary endothelial dysfunction, it is possible that a proportion of them could be clinical manifestations of different mutations of the same gene. The aim of our study was to determine whether mutations of the TCF8 gene, recently implicated in posterior polymorphous dystrophy, may also play a role in the development of the more common Fuchs endothelial corneal dystrophy (FECD). METHODS: Genomic DNA was extracted from leukocytes of peripheral blood, and the nine exons of the TCF8 gene were PCR amplified and subjected to bidirectional sequencing and analysis. Samples from 74 unrelated Chinese patients (55 women, 19 men) with a diagnosis of late-onset FECD and 93 age- and race-matched controls were studied. RESULTS: The affected probands ranged in age from 52 to 91 years (mean age, 65.1 years); 8 had familial FECD and 66 had sporadic FECD. The authors found two mutations in the coding region of the TCF8 gene: a novel missense mutation in one patient c.2087A>G in exon 7 (Asn696Ser) and a silent mutation in exon 2 c.192T>C (D64D). CONCLUSIONS: The identification of a novel missense mutation in only one of the patients implied that TCF8 does not play a significant role in the pathogenesis of FECD in this Chinese population.

SLC4A11 mutations in Fuchs endothelial corneal dystrophy.

The endothelial (posterior) corneal dystrophies, which result from primary endothelial dysfunction, include Fuchs endothelial corneal dystrophy (FECD), posterior polymorphous corneal dystrophy (PPCD) and congenital hereditary endothelial dystrophy (CHED). Mutations in SLC4A11 gene have been recently identified in patients with recessive CHED (CHED2). In this study, we show that heterozygous mutations in the SLC4A11 gene also cause late-onset FECD. Four heterozygous mutations [three missense mutations (E399K, G709E and T754M) and one deletion mutation (c.99-100delTC)] absent in ethnically matched controls were identified in a screen of 89 FECD patients. Missense mutations involved amino acid residues showing high interspecies conservation, indicating that mutations at these sites would be deleterious. Accordingly, immunoblot analysis, biochemical assay of cell surface localization and confocal immunolocalization showed that missense proteins encoded by the mutants were defective in localization to the cell surface. Our data suggests that SLC4A11 haploinsufficiency and gradual accumulation of the aberrant misfolded protein may play a role in FECD pathology and that reduced levels of SLC4A11 influence the long-term viability of the neural crest derived corneal endothelial cells.

Corneal injury by wild taro.

We report a case of crystalline keratopathy caused by Alocasia macrorrhiza. The diagnosis was made based on the observation of needle-like crystals in the corneal stroma following injury to that eye. The condition resolved in 3 months with the disappearance of the crystals confirmed by follow-up confocal microscopy.

Prospective randomized double-masked trial to evaluate perioperative pain profile in different stages of simultaneous bilateral LASIK.

PURPOSE: To evaluate the perioperative pain profile in simultaneous bilateral LASIK. METHODS: Fifty consecutive Chinese patients undergoing simultaneous bilateral LASIK were randomly allocated to have either the right or left eye operated first. The pain scores for each eye at speculum placement, microkeratome cut, laser ablation, and at 15, 30, and 45 minutes after the procedure were recorded. In addition, an overall score for the whole operation was evaluated immediately after the procedure for each eye. Comparisons between eyes and among different stages of the procedures were analyzed. RESULTS: The second eye was significantly more painful than the first eye at the stage of speculum placement and microkeratome pass (P < 0.001). Laser ablation was the least painful stage for both eyes. There were no statistical differences in pain scores for the postoperative period. CONCLUSION: Higher pain scores were associated with the stages involving eyelid manipulation. In patients with small palpebral fissures where stretching of the eyelid structures are anticipated, supplementary anesthesia for the lid region should be considered when required.

Confocal microscopy of posterior polymorphous endothelial dystrophy.

PURPOSE: To report the in vivo confocal microscopic findings of posterior polymorphous endothelial dystrophy (PPED). METHODS: Four patients with PPED from 2 unrelated families and 2 asymptomatic children of an index patient were included in this observational case series. The eyes of the 6 subjects were examined by confocal light microscopy. RESULTS: Confocal microscopy demonstrated craters, streaks, and cracks over the corneal endothelium surface. Pleomorphism and polymegathism were present in eyes with PPED. Guttae and clusters of abnormal endothelial cells were also identified in corneas of these PPED patients. These findings were absent in eyes without clinical manifestations of PPED. CONCLUSIONS: In vivo confocal microscopy is potentially useful for excluding suspected cases of subclinical PPED. Abnormalities in the Descemet membrane and endothelium were observed.

Intravitreal triamcinolone acetonide for choroidal granuloma in sarcoidosis.

PURPOSE: To report the clinical course of intravitreal triamcinolone acetonide on choroidal granuloma secondary to sarcoidosis that was refractory to systemic prednisolone DESIGN: Interventional case report. METHODS: A 29-year-old Chinese man with sarcoidosis presented with isolated posterior segment involvement in his left eye as retinal periphlebitis, retinal granulomas, and choroidal granuloma. Retinal periphlebitis and retinal granulomas responded well to oral corticosteroid but not the choroidal granuloma. It gradually grew in size and caused a drop in left-eye vision to 20/70. Intravitreal triamcinolone acetonide (4 mg) was injected three times in total. RESULTS: The choroidal mass began to shrink in size after the second injection and completely regressed after the third. The choroidal granuloma became a scar, with no angiographic leakage. The patient's visual acuity improved and remained stable at 20/40 at the last follow-up, 6 months after the last injection. CONCLUSIONS: Given the encouraging results, further study on intravitreal triamcinolone acetonide for macular and peripapillary choroidal granulomas secondary to systemic sarcoidosis is warranted.

Intraocular pressure measurement in patients with previous LASIK surgery using pressure phosphene tonometer.

PURPOSE: To compare intraocular pressure (IOP) assessment in post-LASIK patients using non-contact tonometry, pressure phosphene tonometry and applanation tonometry. METHODS: Sixty-two consecutive LASIK patients were analysed preoperatively and postoperatively with non-contact, pressure phosphene and applanation tonometry. Comparisons among these values were assessed with paired sample Student t-test, Pearson's correlation test and Bland-Altman plotting. RESULTS: There was no significant difference for preoperative IOP measurement between non-contact, pressure phosphene and applanation tonometry. The mean +/-SD difference between the preoperative non-contact tonometry and postoperative pressure phosphene tonometry IOP measurements was 0.80 +/- 2.77 mmHg (P < 0.01). Postoperative applanation tonometry significantly underestimated IOP measurement by 5.45 +/- 2.96 mmHg (P < 0.001) and postoperative non-contact tonometry significantly underestimated IOP measurement by 9.96 +/- 2.25 mmHg (P < 0.001). CONCLUSION: Pressure phosphene tonometry may provide an alternative method for the assessment of IOP in post-LASIK patients.

Effect of alcohol on the efficacy of excimer laser power.

PURPOSE: To evaluate the effect of various alcohol concentrations on excimer laser power. SETTING: University Eye Clinic, The Chinese University of Hong Kong, Hong Kong, China. METHODS: The fluency of the Technolas 217z laser (Bausch & Lomb) was calibrated according to the standard calibration procedure. The effect of ethanol 20%, 40%, 60%, and 80% and sodium hypochlorite 0.06% solutions on laser fluency was assessed in 5 experiments. RESULTS: Ethanol concentrations of 20% and 40% had no significant effect on laser fluency. Ethanol concentrations of 60% and 80% reduced fluency to 97.6%. Sodium hypochlorite had no effect on laser fluency. CONCLUSIONS: A high concentration of ethanol affected laser fluency and should be avoided in the operating theater. Ethanol 20%, which is commonly used during laser-assisted subepithelial keratectomy, did not affect laser fluency.

Ptosis after laser in situ keratomileusis.

We present a patient who developed partial ptosis after laser in situ keratomileusis.

In vivo confocal microscopy of Thygeson's superficial punctate keratitis.

A 56-year-old Chinese man diagnosed with Thygeson's keratitis by clinical biomicroscopy was examined using a tandem scanning confocal microscope. Among normal superficial epithelial cells, clumps of markedly enlarged epithelial cells were identified. Multiple highly reflective filamentary structures were observed in the deeper layers. Most of these lesions were linear; some demonstrated curled ends and others demonstrated branching lesions with 'sprouts'. No inflammatory cells were evident in the areas of corneal stroma sampled. In vivo confocal microscopy may be helpful in the diagnosis of Thygeson's superficial keratitis. To the best of our knowledge, we report the first in vivo confocal images of focal desquamation of epithelium and intraepithelial hyper-reflective linear lesions in English literature.

In vivo confocal microscopy of epithelial inclusions from aberrant wound healing after astigmatic keratotomy.

OBJECTIVE: To report confocal microscopic findings in vivo of delayed prominent epithelial inclusions at a gaped incision groove after astigmatic keratotomy (AK). METHODS: Astigmatic keratotomy using paired arcuate incisions was performed on the right eye of a 59-year-old man who had a preoperative refraction of +2.50 DS, -7.00 DC x 80. The procedure and initial postoperative course were uneventful, and his refraction was OD +1.00 DS, -2.50 DC x 60 at 16 months. However, at 17 months postsurgery, tiny pearl-like lesions appeared along one of the incision grooves. In vivo confocal microscopy was performed to investigate these lesions. RESULTS: Under confocal microscopy, clusters of epithelial inclusions inside the gaped incision groove corresponded to the pearl-like lesions observed clinically. A confluent layer of flat, regular and polygonal epithelial cells covered the wall of the groove. Activated keratocytes were observed adjacently. The number of keratocytes around the groove, however, did not appear to increase in comparison to normal corneal wound healing and scar formation. No foreign body, infective, or inflammatory signs were observed. CONCLUSIONS: Aberrant wound healing was identified in post-AK incisions, similar to post-radial keratotomy cases. Confocal microscopy is a useful tool to study the wound healing of AK incisions and to rule out foreign bodies or infective elements as illustrated by this case. To the best of our knowledge, this is the first reported in vivo confocal study of AK wound healing in humans.

In vivo confocal microscopic findings in patients with steroid-induced glaucoma after LASIK.

OBJECTIVE: To report the confocal microscopic findings of 2 different cases of steroid-induced glaucoma after LASIK. DESIGN: Observational case report of 2 cases. METHODS: Two cases of steroid-induced glaucoma after LASIK were selected. Examination with a white-light tandem slit-scanning confocal microscope was performed in addition to routine slit-lamp biomicroscopy. MAIN OUTCOME MEASURES: In vivo confocal findings at the flap interface. RESULTS: In both cases, the interfaces were identified at a deeper level than expected. Confocal microscopic examination did not show mononuclear cells and granulocytes typically seen in patients with classic diffuse lamellar keratitis. CONCLUSION: Our findings confirm that steroid-induced glaucoma after LASIK is not associated with the collection of inflammatory cells. The treatment option of lowering the intraocular pressure is effective in treating the disease, even without anti-inflammatory medications. Confocal in vivo microscopy is a useful tool to study the course of steroid-induced glaucoma after LASIK in humans.

Orthokeratology lens-related corneal ulcers in children: a case series.

OBJECTIVE: Orthokeratology is a process by which the corneal curvature is flattened by sequentially fitting rigid gas permeable contact lenses of decreasing central curvature. There has been a resurgence of interest with the recent introduction of reverse geometry lenses. Although promising results have been described in reducing the myopic refractive error, the use of these lenses can be associated with corneal problems, as reported in this case series. DESIGN: Observational case series. PARTICIPANTS: Six children with orthokeratology-related corneal ulcers. METHODS: Consecutive cases of orthokeratology lens (OKL)-related corneal ulcers in children presented to a tertiary referral center (March 1999-June 2001) were reviewed. MAIN OUTCOME MEASURES: Preinfection and postinfection visual acuity, refraction, any organisms identified. RESULTS: Six children between the ages of 9 and 14 years (mean = 12.1) were treated. The male:female ratio was 1:5. All cases were unilateral, with equal numbers of left and right eyes. All children wore the OKL at night for a duration of 8 to 12 hours, with the onset of infection between 3 and 36 months (mean = 16.6) of OKL wear. All of the patients suffered a resultant best-corrected visual acuity loss. Five of the 6 cases were culture positive for Pseudomonas aeruginosa. CONCLUSIONS: In view of the temporary benefits of orthokeratology, together with a known increased risk of infection associated with overnight lens wear, parents of children considering orthokeratology must be informed and warned of the potential for permanent loss of vision. The ophthalmic community should have a heightened awareness of the associated complications.

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.