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.

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.

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.

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.

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.

In vivo confocal microscopic findings in patients with Steroid-Induced glaucoma after LASIK*1

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.

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.

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.

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.

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.

Bilateral peripheral corneal infiltrates after simultaneous myopic laser in situ keratomileusis

We describe a patient with multiple superior corneal infiltrates in both eyes, separated from the limbus by an intervening clear zone, that appeared 1 day after uneventful laser in situ keratomileusis. The overlying epithelium was intact, and the flap and interface were uninvolved. Based on these features, a clinical diagnosis of sterile corneal infiltrates was made and the eyes were treated with topical antibiotics and steroids. The infiltrates resolved during the ensuing weeks without corneal scarring. Good visual acuity was maintained. Recognition of this benign complication is important because aggressive corneal scrapings are not required. The infiltrates appear to be immunogenic in origin, although the exact etiopathogenesis is not clear.

Topical chloramphenicol for eye infections

Topical chloramphenicol has been widely used in the treatment and prevention of superficial eye infections due to its broad spectrum of activity and low cost. The use of this drug has decreased considerably in the United States since the first case of aplastic anaemia associated with topical chloramphenicol was reported in the 1960s. This medication, however, is still widely used in many other countries. This paper evaluates the evidence for and against the use of topical chloramphenicol in ocular diseases.