Macular involvement in congenital aniridia

This review updates the knowledge about the morphological assessment of the foveal hypoplasia in congenital aniridia and resumes the reported genotype-phenotype correlations known to date. Congenital aniridia is a pan ocular disease. Although iris absence is considered the hallmark of this entity, foveal hypoplasia is present in 94.7%-84% of patients. A foveal morphology assessed by optical coherence tomography in which external retina structures can be identified, with presence of the lengthening of photoreceptors outer segment and a greater external retinal thickness, is associated with a better visual outcome, regardless a foveal pit is identified or not. This analysis can be performed once the external retina has completed its differentiation, by 6 years old. PAX6 mutations that introduce premature termination codon, C terminal extension or PAX6 involving deletions have been related to lesser foveal differentiation. Better foveal differentiation has been associated to non-coding PAX6 mutations.

Macular involvement in congenital aniridia

This review updates the knowledge about the morphological assessment of the foveal hypoplasia in Congenital Aniridia and resumes the reported genotype-phenotype correlations known to date. Congenital Aniridia is a pan ocular disease. Although iris absence is considered the hallmark of this entity, foveal hypoplasia is present in 94.7-84% of patients. A foveal morphology assessed by optical coherence tomography in which external retina structures can be identified, with presence of the lengthening of photoreceptors outer segment and a greater external retinal thickness, is associated with a better visual outcome, regardless a foveal pit is identified or not. This analysis can be performed once the external retina has completed its differentiation, by 6 years old. PAX6 mutations that introduce premature termination codon, C terminal extension or PAX6 involving deletions have been related to lesser foveal differentiation. Better foveal differentiation has been associated to non-coding PAX6 mutations.

Evaluation of femtosecond laser-assisted cataract surgery after 10 years of clinical application

INTRODUCTION

Femtosecond laser-assisted cataract surgery (FLACS) has been considered a technological advance in modern cataract surgery. After years of experience, it has been observed that clinical outcomes had more complications than expected at the beginning. The aim of this study is to compare the benefits and disadvantages of the FLACS technique with conventional cataract surgery.

METHOD

The PubMed and Web of Science platforms were used to search for scientific literature.

RESULTS

The FLACS has currently improved the surgical technique in terms of the shorter ultrasound time used and the lower loss of endothelial cells. Likewise, the centration of capsulotomy and the correction of astigmatism with arcuate incisions have also been improved. As disadvantages, are the high cost of the laser, the intraoperative capsular complications, the induction of intraoperative myosis, and the learning curve of the technique.

CONCLUSIONS

The FLACS technique is considered beneficial for specific cases, such as patients with scheduled premium surgery, or with low endothelial cell count. However, it is believed that given the technological cost it is not a cost effective technique for most standard cases in our daily clinical practice.

Phakic intraocular lenses: Recent advances and innovations

Phakic intraocular lenses (pIOL) are recommended when counselling refractive surgery candidates presenting with high ametropia or ocular surface and/or corneal conditions that contraindicate corneal refractive surgery. This review aims to present the state-of-the-art regarding pIOL models currently available in Europe, addressing their newer indications and recent design innovations. These include, in the case of posterior chamber pIOLs, the addition of a central hole to improve aqueous humour circulation, the availability of larger optical zones, and multifocal optics for the compensation of presbyopia. The review also highlights their good safety and efficacy results, as well as the role of patient education to ensure adequate outcomes in the medium-long term. The indications of pIOLs in special situations, as well as bi-lensectomy, a procedure that most pIOL patients may eventually require as they age and develop cataracts, are also addressed.

An angle-supported foldable phakic intraocular lens for correction of myopia: A five-year follow-up

OBJECTIVE

To evaluate the efficacy and safety of an angle-supported foldable phakic intraocular lens (pIOL) for the correction of moderate to high myopia after 5 years follow-up.

METHODS

Prospective and retrospective, observational, longitudinal, non-randomised consecutive series of cases conducted on a total of 100 eyes of 67 patients with moderate to high myopia implanted with an Acrysof Cachet pIOL (Alcon Laboratories Inc.) with the aim of minimising the refractive error. The ages ranged between 18 to 60years. Uncorrected distance visual acuity (UDVA), manifest refraction, corrected distance visual acuity (CDVA), endothelial cells density, pIOL position, intraocular pressure, and complications were recorded preoperatively and during the 5 year follow-up.

RESULTS

Five years after implantation, the mean manifest spherical equivalent refraction reduced significantly from -11.62±3.35 dioptres (D) to -0.33±0.85D. UDVA was 20/20 or better in 5 of 25 cases (20%), and 20/40 or better in 22 cases (88%). CDVA was 20/20 or better in 17 cases (68%), and 20/32 or better in 23 cases (92%) of eyes. The residual refractive error was within ±0.50D of emmetropia in 12 cases (48%), and within ±1.00D in 19 cases (76%). Mean endothelial cell loss at 5 years was 11.8% central, and 13.7% peripheral. Mean endothelium-pIOL distance was 2.11±0.18mm, and mean pIOL-crystalline distance was 0.88±0.20mm.

CONCLUSIONS

This angle supported pIOL provided a favourable refractive correction and predictability, as well as acceptable safety in patients with moderate to high myopia. Although endothelial cell density decreased over 5years, the results are within the range reported in previous studies with other pIOLs.

Current and Future Applications of Photoactivated Chromophore for Keratitis-Corneal Collagen Cross-Linking (PACK-CXL): An Overview of the Different Treatments Proposed

PURPOSE

To review the application of the PACK-CXL and to identify different treatment protocols according to the pathogens associated with keratitis.

METHODS

A systematic review of 21 articles. The primary outcome was the healing of a corneal ulcer, defined as epithelization, blocking corneal melting. The secondary end-point was the recovery of visual acuity.

RESULTS

We studied a total of 145 eyes. Infectious keratitis was associated with bacteria in 80 eyes (55.55%), fungus in 24 eyes (16.67%), and protozoa in 13 (8.97%). In 26 (18%), the microbiological culture was negative or not performed. The mean time of re-epithelization was 25.70±29.83days (1-180). A total of 27 patients needed corneal transplantation. The overall probability of blocking corneal melting was 84.13%. Three different protocols for each group of pathogens have been proposed.

CONCLUSION

PACK-CXL still has a limit in its spread. In the future, we hope that each pathogen will be treated with the most efficient and least invasive protocols available.

Infectious Keratitis Following Corneal Crosslinking: A Systematic Review of Reported Cases: Management, Visual Outcome, and Treatment Proposed

AIM

To describe the infectious complications and the group of pathogens involved in the infection following corneal crosslinking, the visual outcome, and the treatment proposed.

METHODS

A Medline (National Library of Medicine, Bethesda, MD, USA) search from October 2000 to October 2013 was performed to identify all articles describing infectious keratitis following corneal crosslinking treatment. Nineteen articles were selected. Ten articles reported infectious complications of corneal crosslinking treatment were included. Nine articles were excluded, because seven described sterile keratitis, one article was in German, and one reported general complication without describing the infection complication.

RESULTS

A total number of infections reported included 10 eyes. The infectious keratitis was associated with bacteria in five eyes (50%): gram-positive bacteria in three eyes (30%) (staphylococcus epidermidis, S. aureus and streptococcus salivarius plus S. oralis, respectively) and gram-negative bacteria in two eyes (20%) (E. coli; P. aeruginosa); there was herpes virus in two eyes, fungus in two eyes (Fusarium and Microsporidia) (20%), and Acanthamoeba in one eye (10%).

CONCLUSIONS

Only 10 cases of infectious keratitis following corneal crosslinking are published. The most virulent pathogens were Pseudomonas aeruginosa and Acanthamoeba. Less virulent organisms were Escherichia coli and S. epidermidis. Two cases of herpes keratitis were described, suggesting the possibility of systemic antiviral prophylaxis before corneal crosslinking treatment. The most common risk factor of infections identified was postoperative incorrect patient behavior.

Protective Effect of Viscoelastics against Retina Lipid Peroxidation

Viscoelastics or ophthalmic viscosurgical devices are routinely used during anterior segment surgery and also in posterior segment surgery. Studies of the harmful effects of phacoemulsification on corneal endothelial cells suggest that much of this damage is mediated by free radicals. In this study, we compare the possible effects against lipid peroxidation in the retina of three different viscoelastic substances: Viscoat, Healon and Visiol. Herein we demonstrate for the first time that viscoelastics are effective to protect the retina against lipid peroxidation, as can be seen by the slight increase of malondialdehyde in the homogenates incubated with viscoelastic exposed to light and to a temperature of 37 degrees C when compared with the control homogenates.

Actinomyces neuii subspecies anitratus chronic endophthalmitis after cataract surgery

PURPOSE

To report a case of unusual chronic endophthalmitis by Actinomyces neuii subspecies anitratus.

METHODS

A 75-year-old man underwent uneventful phacoemulsification with implantation of a foldable posterior chamber intraocular lens in his right eye. Four weeks after surgery, a chronic post-operative endophthalmitis characterized by anterior chamber and vitreous cellular debris developed in this eye. Cultures were positive, and A neuii subspecies anitratus was identified by polymerase chain reaction and subsequent rRNA sequence analysis. Immediate treatment included intravitreal and intensive topical antibiotics along with oral ciprofloxacin.

RESULTS

The condition improved rapidly, and 6 months after surgery the patient was asymptomatic, the best spectacle-corrected visual acuity was 20/22, and the anterior chamber was quiet.

CONCLUSIONS

A neuii subspecies anitratus should be considered in the differential diagnosis of chronic endophthalmitis after cataract surgery. Polymerase chain reaction and subsequent RNA typing were useful in detecting the causative organism, and intravitreal antibiotics were successful.

New frontiers for the perioperative data method for IOL calculation following corneal refractive surgeries

PURPOSE

To evaluate the efficiency of the perioperative data method for intraocular lens (IOL) calculation after correction of myopia and hyperopia with different techniques, including reoperated cases.

METHODS

Thirty-five eyes (26 patients) that developed cataract after corneal refractive procedures were evaluated retrospectively. They were categorized according to initial error of refraction into myopes and hyperopes and according to types of refractive procedures into ablative, incisional, both, or others. Reoperated cases were also considered. Number of refractive procedures was noted. Time interval between the first procedure and cataract extraction was indicated. Perioperative method was used to calculate the K value. SRK/T formula was used to calculate IOL power. Difference between intended and finally achieved manifest refraction was an indicator for efficiency of the calculation.

RESULTS

Postoperatively, 77.2% of cases had manifest refraction +/-1.5 D of intended refraction. There was no difference between myopes and hyperopes in terms of final manifest refraction, best-corrected visual acuity, and difference between intended and finally achieved manifest refraction. Similarly were groups of different types of surgeries. Efficiency of the method decreased with high axial lengths and low IOL powers. Neither the number of refractive surgeries nor time interval between surgeries affected efficiency of the method.

CONCLUSIONS

The perioperative data method is equally effective for myopes and hyperopes. The types, numbers of refractive procedures, as well as the time interval between refractive surgery and cataract extraction do not alter the credibility of the method. In high degrees of myopia, the method gives less accurate results.

[Variation of central corneal thickness in diabetic patients as detected by ultrasonic pachymetry]

OBJECTIVE

To prove the existence of a correlation between central corneal thickness and diabetes.

METHODS

Ultrasound pachymetry measurements were made in 1,000 patients. The sample was divided into two groups of patients: 953 of them were non-diabetic patients, and 47 were diabetic patients.

RESULTS

The average central corneal thickness in diabetic patients was 571.96 +/- 26.81 microns with a range between 514 and 626. The average central corneal thickness found in non-diabetic patients was 544.89 +/- 35.36 microns with range of 448 to 649. The increase in central corneal thickness found in diabetic patients compared to non-diabetic patients was statistically significant (p<0.001, Student "t" test).

CONCLUSIONS

We found that diabetic patients had an increased central corneal thickness when compared with non-diabetic patients.

Adal-1 bioadhesive for sutureless recession muscle surgery: a clinical trial

AIMS

To evaluate the efficacy and biotolerance of the Adal-1 adhesive for muscle sealing in strabismus surgery.

METHODS

27 eyes were included in the study: 17 in the control group and 10 in the study group. Surgery was performed on the recession of the horizontal rectus muscles. In the control group the muscle was joined to the sclera by a Vicryl 7/0 suture. In the study group, the Adal-1 adhesive was used instead. The efficacy of the sealing of the muscle to the sclera and the biotolerance of the surrounding tissues were evaluated.

RESULTS

The muscular recession in the control group was 8.17 (SD 2.38) with displacement of the sealing point of 0.02 (1.7) mm. In the group sealed with adhesive, the muscular recession was 9.09 (3.08) and the displacement was 0.15 (1.56) mm, with no significant differences between the techniques (p<0.05). The inflammation of the surrounding tissues in the immediate postoperative period was greater with the suture technique (p>0.05), but there were no differences in the other postoperative periods (Mann-Whitney U test).

CONCLUSION

Adal-1 was an effective and safe alternative to sutures in muscle recession for strabismus surgery in this study.

[Chronic blepharitis and Demodex]

PURPOSE

Demodex is a mite commonly found in eyelash hair follicles and sebaceous glands of healthy people. Due to the fact this mite has also been reported in many chronic cases of blepharitis, we aimed to investigate the incidence of infestation with this mite in healthy people and in patients with chronic blepharitis, in addition to evaluating the response to the different treatments used for blepharitis.

METHODS

105 subjects without blepharitis were selected as a control group and 20 subjects diagnosed as having chronic blepharitis were selected as patients. Epilated eyelashes were observed under microscope in both groups of patients. Those with overpopulation of mites were treated with ether lid and eyelash scrubs and 2% mercury oxide ointment.

RESULTS

The incidence of Demodex infestation in the control group was 0.08 mites per eyelash, whereas in the patients with chronic blepharitis the incidence was 0.69 mites per eyelash; this difference was statistically significant (p=0.006). All the mites found were Demodex folliculorum except in one patient where the mite was identified as Demodex brevis. After 3-8 weeks of specific treatment the number of mites per eyelash decreased dramatically (0.03, with p=0.001). Two patients were intolerant of the therapy.

CONCLUSIONS

In this study the incidence of Demodex in patients with blepharitis was very high, when compared with normal subjects, showing a clear association between blepharitis and Demodex infestation. Treatment with mercury oxide ointment was satisfactory in controlling the infection, despite difficulty in its application and occasional toxicity.

[Confocal microscopy of the cornea in photorefractive surgery]

OBJECTIVE

Corneal refractive surgery involves a range of techniques which have assumed a growing importance during the last few years. The advances of very different surgical methods and the early age of the majority of the patients subjected to surgery, limits our knowledge of the histopathologic changes in the operated corneas. For this reason, the development of any diagnostic tool which can permit us to improve our knowledge of the wound healing process would be of significant value. As we describe in our paper, confocal microscopy enables the assessment of the more important advantages for the study of corneal wound healing after refractive surgery: high magnification, harmless, and "in vivo", providing pathogenic information and lateral and axial definition not achievable with other exploration techniques.

CONCLUSION

Confocal microscopy appears to be an essential tool for creating a global concept of quality in corneal refractive surgery.

Five year follow up of biocolonisable microporous fluorocarbon haptic (BIOKOP) keratoprosthesis implantation in patients with high risk of corneal graft failure

AIM

To study the anatomical and visual performance following implantation of a model of artificial cornea and to evaluate the postoperative long term complications.

METHODS

11 eyes of 11 patients with bilateral corneal blindness considered as potentially having high risk of failure of penetrating corneal keratoplasty were implanted with biocolonisable Kpro keratoprosthesis (BIOKOP I, FCI, Rantigny, France) in the period between January 1996 and May 1998. Only one eye was implanted in all patients and followed up for a period of 60 months. The visual outcome, anatomical and functional stability, complications, and the general performance of the keratoprosthesis were evaluated.

RESULTS

The keratoprosthesis (BIOKOP I) only 36.3% remained in position to date. In the patients' last visit five eyes (45.4%) were blind and one (9.0%) showed a slight improvement in the best corrected visual acuity (BCVA) in comparison to preoperative tests. Six eyes (54.5%) showed improved BCVA before having postoperative complications. Four eyes underwent replacement of a BIOKOP I Kpro with a BIOKOP II as a result of extrusion. The keratoprostheses remained anatomically in situ for a mean of 25.5 months and their functional performance period was limited to a mean of 22 months.

CONCLUSION

Corneal keratoprosthesis (BIOKOP I, II) does not provide a stable anatomical relation with the surrounding ocular structures. Its ability to restore vision is limited to a short postoperative period in eyes implanted with severe ocular surface disease.

Choroidal neovascularization in myopic eyes after phakic refractive lens and iris-claw lens implantation

PURPOSE

To describe the appearance of choroidal neovascularization (CNV) in two myopic patients after implantation of a phakic refractive lens (PRL) and an iris-claw lens.

METHODS

A PRL was implanted in the left eye of a 35-year-old myopic man. Five weeks later, he reported decreased best-corrected visual acuity (BCVA). Fluorescein angiography revealed juxtafoveal CNV Photodynamic therapy with Visudyne (PDT) was successfully performed, achieving closure of the membrane. BCVA was 20/40 3 months afterwards. An iris-claw lens was implanted in the left eye of a 24-year-old myopic man. BCVA after surgery was 20/40 (SE -0.75). Three years later subfoveal CNV was diagnosed. PDT was performed, achieving complete closure of CNV BCVA was 20/100 3 months after treatment.

CONCLUSIONS

The appearance of CNV in myopic eyes corrected by phakic intraocular lens implantation is a possible complication that must be considered.

Ring electrode for radio-frequency heating of the cornea: modelling and in vitro experiments

Radio-frequency thermokeratoplasty (RF-TKP) is a technique used to reshape the cornea curvature by means of thermal lesions using radio-frequency currents. This curvature change allows refractive disorders such as hyperopia to be corrected. A new electrode with ring geometry is proposed for RF-TKP. It was designed to create a single thermal lesion with a full-circle shape. Finite element models were developed, and the temperature distributions in the cornea were analysed for different ring electrode characteristics. The computer results indicated that the maximum temperature in the cornea was located in the vicinity of the ring electrode outer perimeter, and that the lesions had a semi-torus shape. The results also indicated that the electrode thickness, electrode radius and electrode thermal conductivity had a significant influence on the temperature distributions. In addition, in vitro experiments were performed on rabbit eyes. At 5 W power, the lesions were fully circular. Some lesions showed non-uniform characteristics along their circular path. Lesion depth depended on heating duration (60% of corneal thickness for 20 s, and 30% for 10 s). The results suggest that the critical shrinkage temperature (55-63 degrees C) was reached at the central stroma and along the entire circular path in all the cases.

Visual performance after congenital nystagmus surgery using extended hang back recession of the four horizontal rectus muscles

PURPOSE

To evaluate the results of surgical correction of congenital nystagmus based on the use of extensive recessions of the four horizontal rectus muscles. The outcome of this procedure in terms of visual performance of the patients has been analyzed in follow-ups of at least 1 year.

METHODS

Surgery was performed on 42 patients. An extended retroequatorial recession of the four horizontal rectus muscles was performed between 13 and 15 mm from the muscle insertion with hang back sutures in every case. Preoperatively, all cases showed either a horizontal pendular (4 cases) or jerk nystagmus (38 cases).

RESULTS

After surgery, all cases showed full preservation of ductions in all gaze positions. Torticollis decreased in all cases. Binocular best-corrected vision improved in 19 (45.2%) patients and in the remaining 23 (54.8%) it remained unchanged. Consecutive exotropia was observed postoperatively in 7 patients. A second surgical procedure was performed in 9 cases (21.4%) and a botulinum injection in 3 cases (7%). All cases of diplopia resolved. Patient satisfaction was high in 38 cases (96%).

CONCLUSIONS

Extended recession of horizontal rectus muscles using hang back sutures offers a good option for the surgical correction of sensorial and neuromuscular nystagmus, providing improvement in binocular best-corrected vision in 45% of the patients (21.4% more than 0.2 logMar units), a high satisfaction rate, and few associated complications. In patients with low vision this can be considered a success that may improve quality of life.

Follicular conjunctivitis caused by Chlamydia trachomatis in an infant Saharan population: molecular and clinical diagnosis

AIMS

To ascertain the prevalence of acute trachoma as a supposed endemic disease among infants in the Saharan refugee camps of Tindouf (Algeria) and to evaluate the efficacy of treatment with a single dose of azithromycin.

METHODS

527 children aged between 3 and 17 were evaluated in the camp schools in October 2001. All the children were clinically and microbiologically examined, including slit lamp checks of anterior segment and two conjunctival swabs, one for the detection of membrane lipopolysaccharide by quick immunoassay test Clearview Chlamydia MF and the other for the detection of specific DNA by chlamydia plasmid specific polymerase chain reaction (PCR) assay. After examination, a single dose of azithromycin was administered to each child. One month later samples from positive children and 12 random negative children by the first PCR were taken to perform a new PCR assay.

RESULTS

Chlamydia trachomatis was suspected in 2.47% of the children, papillary hypertrophy being the most frequently seen clinical sign. Scarring changes secondary to trachoma were detected in 11.7% of the children. Only four cases (0.8%) were positive to the immunoassay test and 12 cases (2.27%) were positive by PCR. After treatment a second PCR was performed on positive children and they were negative of chlamydia DNA amplification. However, one child who was negative and received the treatment was positive in the second PCR assay.

CONCLUSION

Acute trachoma prevalence is much lower than expected among infants in this Saharan population. The possible reasons could be the recent improvements in hygiene and health care. Cicatricial trachoma is more frequent. The Clearview immunoassay test has very low sensitivity in the detection of this disease. A single dose of azithromycin is sufficient to treat chlamydial conjunctivitis. However, a programme of improvement in hygiene and health care is necessary to prevent re-infection.

Haze after laser in situ keratomileusis in eyes with previous photorefractive keratectomy

In cases with previous photorefractive keratectomy (PRK), there is a risk of developing severe haze after laser in situ keratomileusis (LASIK). We report 3 patients (4 eyes) who developed severe haze after LASIK treatment for residual myopia following PRK. Both PRK and LASIK procedures were performed using the VISX 20/20 excimer laser. We report the grade of haze, amount of regression, and visual acuity after the patients were treated with topical steroids. In 2 eyes, the uncorrected visual acuity was 1.0 after 1 year with grade I haze. In the other 2 eyes, there was a residual refractive error, and the best spectacle-corrected visual acuity was 0.7 with grade II haze.

Choroidal neovascularization in myopic eyes after laser-assisted in situ keratomileusis

PURPOSE

To analyze the appearance and characteristics of choroidal neovascularization (CNV) in patients with high myopia corrected by laser-assisted in situ keratomileusis (LASIK).

PATIENTS AND METHODS

The authors studied CNV in 2955 consecutive eyes (1632 patients) that underwent LASIK for the correction of myopia (from -6 to -27.5 diopters). Follow-up was 34.2+/-11.3 months.

RESULTS

Choroidal neovascularization occurred in three eyes (0.10%) and in one eye previous CNV was reactivated (three women, one man). The time interval between refractive surgery and CNV was 13+/-9.5 months (range, 4-26 months). Mean best-corrected visual acuity (BCVA) after LASIK and before CNV development was 20/57 (range, 20/100-20/29). After the appearance of CNV, mean BCVA was 20/606 (range, 20/2000-20/80). Differences between BCVA before and after CNV were statistically significant (P = 0.04, paired Student's t-test). The CNV was treated in two cases by argon laser photocoagulation and in two cases by surgical excision of CNV by vitrectomy. The final mean BCVA was 20/277 (range, 20/800-20/50). Differences between BCVA after LASIK and after CNV treatment were statistically significant (P = 0.04, paired Student's t-test).

CONCLUSIONS

Laser-assisted in situ keratomileusis as a correcting procedure for myopia was followed by low appearance of CNV. The appearance and treatment of CNV was followed by a significant decrease of BCVA.

Detection and identification of fungal pathogens by PCR and by ITS2 and 5.8S ribosomal DNA typing in ocular infections

The goal of this study was to determine whether sequence analysis of internal transcribed spacer/5.8S ribosomal DNA (rDNA) can be used to detect fungal pathogens in patients with ocular infections (endophthalmitis and keratitis). Internal transcribed spacer 1 (ITS1) and ITS2 and 5.8S rDNA were amplified by PCR and seminested PCR to detect fungal DNA. Fifty strains of 12 fungal species (yeasts and molds) were used to test the selected primers and conditions of the PCR. PCR and seminested PCR of this region were carried out to evaluate the sensitivity and specificity of the method. It proved possible to amplify the ITS2/5.8S region of all the fungal strains by this PCR method. All negative controls (human and bacterial DNA) were PCR negative. The sensitivity of the seminested PCR amplification reaction by DNA dilutions was 1 organism per PCR, and the sensitivity by cell dilutions was fewer than 10 organisms per PCR. Intraocular sampling or corneal scraping was undertaken for all patients with suspected infectious endophthalmitis or keratitis (nonherpetic), respectively, between November 1999 and February 2001. PCRs were subsequently performed with 11 ocular samples. The amplified DNA was sequenced, and aligned against sequences in GenBank at the National Institutes of Health. The results were PCR positive for fungal primers for three corneal scrapings, one aqueous sample, and one vitreous sample; one of them was negative by culture. Molecular fungal identification was successful in all cases. Bacterial detection by PCR was positive for three aqueous samples and one vitreous sample; one of these was negative by culture. Amplification of ITS2/5.8S rDNA and molecular typing shows potential as a rapid technique for identifying fungi in ocular samples.

Laser in situ keratomileusis for treatment of residual myopia after photorefractive keratectomy

PURPOSE

To evaluate the results of laser in situ keratomileusis after photorefractive keratectomy.

METHODS

Eighty eyes of 80 patients with residual myopia after photorefractive keratectomy were reoperated with laser in situ keratomileusis. The study was retrospective. Laser in situ keratomileusis was performed using the automated corneal shaper microkeratome and Chiron Technolas 217-C d1 excimer laser. Data measured after laser in situ keratomileusis included uncorrected visual acuity, best-corrected visual acuity, refraction, haze, pachymetry, and keratometry. The follow-up was at least 12 +/- 1.6 months (range, 12 to 15 months).

RESULTS

After laser in situ keratomileusis the mean spherical equivalent was -0.24 diopters +/- 0.78. (range, -3 to +1.5) at 12 months, and the mean uncorrected visual acuity was 0.76 diopters +/- 0.24 (range, 0.1 to 1). Sixty-five eyes (81.3%) had various degrees of haze after laser in situ keratomileusis. One eye (1.2%) lost 2 lines of best-corrected visual acuity.

CONCLUSIONS

Laser in situ keratomileusis enhancement may be a good alternative to correct residual myopia and astigmatism after primary photorefractive keratectomy. Corneal haze is a common problem in these eyes, and the treatment after laser in situ keratomileusis enhancement should be the same as the treatment after primary photorefractive keratectomy.

Reversal of Myopic Anisometropic Amblyopia With Phakic Intraocular Lens Implantation

PURPOSE

To report a case of reversal of myopic anisometropic amblyopia with phakic intraocular lens implantation.

METHODS

A 6-year-old boy with anisometropic amblyopia with spherical equivalent refraction of right eye: -14.00 -3.00 x 100 degrees, left eye: -0.50 -3.25 x 90 degrees, was treated for 2 years with occlusion to the left eye, with poor results. Refractive surgery was planned because of contact lens intolerance at age 8 years. A -15.00-D iris claw Artisan intraocular lens (IOL) was implanted.

RESULTS

Following surgery, treatment of the amblyopia and spectacle correction of -4.00 D cylinder at 85 degrees in the right eye and -3.50 D cylinder at 90 degrees in the left eye was necessary. Visual acuity 6 months after surgery was 20/25 in the right eye and 20/20 in the left eye, and has remained stable 18 months after surgery.

CONCLUSION

Myopic anisometropic amblyopia in an 8-year-old boy was treated successfully with implantation of an Artisan iris claw phakic anterior chamber IOL, combined with occlusion therapy, and resulted in reversal of amblyopia.

Correction of irregular astigmatism with excimer laser assisted by sodium hyaluronate

PURPOSE

To demonstrate the usefulness of excimer laser surgery assisted by sodium hyaluronate for the correction of irregular astigmatism after previous corneal refractive surgery.

DESIGN

Prospective noncomparative case series.

PARTICIPANTS

Fifty eyes with surgically induced irregular astigmatism. All the patients had been subjected previously to one or more of the following: laser in situ keratomileusis (LASIK), incisional keratotomy, photorefractive keratotomy, phototherapeutic keratotomy, laser thermokeratoplasty, and corneal trauma. Irregular astigmatism developed thereafter.

METHODS

Stability of the corneal topography pattern before surgical decision was observed for at least 6 months with the C-SCAN corneal topography with Ray Tracing (Technomed GmbH, Germany) and the Eye-Sys 2000 Corneal Analysis System (Eye Sys Co., Houston, TX). The lowest pachymetry value was 310 microm in the thinnest portion of the cornea. Ablation was performed with the Technolas 217 C-LASIK excimer laser (Bausch and Lomb Chiron Technolas GmbH, Dornach, Germany), in phototherapeutic keratectomy mode, assisted by a mask of 0.25% sodium hyaluronate. We performed our ablation either on the surface or under a flap, whether elevated or newly cut.

MAIN OUTCOME MEASURES

Uncorrected and best-corrected visual acuity, manifest and cycloplegic refraction, superficial corneal surface quality, image distortion, and predicted corneal visual acuity.

RESULTS

At 3 months of follow-up, the irregular corneal surface was significantly improved in all cases (n = 50). The superficial corneal surface quality improved from 70.5% +/- 9.16% to 75.6% +/- 10.38 (P < 0.0001). Six eyes lost 1 line of best-corrected visual acuity, three eyes lost 2 lines, and five eyes lost 3 or more lines. The real corneal ablation depth obtained was equal to 63% of that programmed because of the influence of masking substance. Mean uncorrected visual acuity improved from 20/80 +/- 20/125 to 20/63 +/- 20/100 (P = 0.01). Predicted corneal visual acuity improved from a mean of 20/32 +/- 20/80 to 20/25 +/- 20/63 (P = 0.004). Image distortion improved from a mean of 13.95 +/- 3.64 to 12.16 +/- 3.92 (P < 0.0001). We obtained a hyperopic shift in 56% and myopic shift in 40% of eyes. After 6 months of follow-up the irregular corneal surface continued to improve in all cases (n = 32). The superficial corneal surface quality improved from 69.38% +/- 9.48% to 73.13% +/- 8.87 (P = 0.002). Two eyes lost 2 lines of best-corrected visual acuity, and 3 eyes lost 1 line. Ray tracing was significantly improved in all cases at the end of follow-up regarding superficial corneal surface quality (P = 0.002) and the image distortion (P = 0.05). Improvement of predicted corneal visual acuity was not significant (P = 0.11). The procedure proved to be safe, with a safety index of 1.1. Differences between the surface and stromal treatments and between pattern and nonpattern irregular astigmatism were not statistically significant.

CONCLUSION

It is possible to produce a more regular corneal surface and to improve best-corrected visual acuity in patients with irregular astigmatism using plano-scan excimer laser assisted by viscous masking solution of 0.25% sodium hyaluronate.

[Circular flap rhexis: a refinement technique for LASIK re-treatment]

PURPOSE

To describe a new approach to re-treatment after Laser in situ keratomileusis (LASIK) by means of lifting the corneal flap in order to decrease the epithelial damage and its related complications, such as epithelial ingrowth and flap melting, which are more frequent after LASIK re-treatment than after primary LASIK.

MATERIAL AND METHODS

The new technique, called circular flap rhexis, is based on a careful flap edge identification, linear epithelial tear for minimizing epithelial irregularities and defects, and a delicate flap replacement to promote a strong adhesion between the flap edge and the stromal bed. The LASIK re-treatment with this flap rhexis technique was performed in 43 eyes at 3 or 6 months after the primary LASIK. After a 12 month follow-up, the epithelial ingrowth and flap melting rates were recorded.

RESULTS

Epithelial growth was found in 9.3% of the cases (4 out of 43 eyes) and flap melting in 2.3% of the cases (1 out of 43) at 12 months after LASIK re-treatment by circular flap rhexis. These disorders were always peripheral and did not affect visual acuity or corneal astigmatism.

CONCLUSION

LASIK re-treatment using circular flap rhexis is an effective technique to decrease the epithelium related complications after LASIK re-treatment.

Delayed-onset postoperative endophthalmitis caused by Hafnia alvei

PURPOSE

To identify Hafnia alvei as an etiological factor of delayed-onset endophthalmitis.

CASE REPORT

A 68-year-old woman had uneventful cataract extraction by phacoemulsification with foldable posterior chamber intraocular lens implantation under topical anesthesia in the left eye. Four weeks later, the patient presented anterior uveitis treated by topical corticosteroids. Seven weeks later a posterior uveitis with retinal vasculitis appeared. The patient was treated by systemic and intravitreal corticosteroids without result. Due to the poor course pars plana vitrectomy was done, and a vitreous sample was taken. Microbiologic examination disclosed Hafnia alvei, gram-negative bacteria rarely isolated from human specimens.

CONCLUSIONS

Hafnia alvei should be considered in the etiology of delayed-onset endophthalmitis.

Laser in situ keratomileusis for undercorrection and overcorrection after radial keratotomy

PURPOSE

To evaluate laser in situ keratomileusis (LASIK) in the management of overcorrection and undercorrection after radial keratotomy (RK).

SETTING

Instituto Oftalmológico de Alicante, Alicante, Spain.

METHODS

This prospective study comprised 20 eyes of 13 patients. The eyes were divided into 2 groups: 11 eyes that were overcorrected after RK and 9 eyes that were undercorrected after RK. Both groups were treated with LASIK after a mean interval of 22 months +/- 8.4 (SD) (range 12 to 45 months). The follow-up was 6 months.

RESULTS

Six months after LASIK, there was a significant decrease in the spherical equivalent in both groups. Ninety-one percent of eyes in the overcorrected group and 89% in the undercorrected group were within +/-1.0 diopter of the intended correction. There was a significant improvement in the uncorrected visual acuity in both groups. In the overcorrected group, 91% showed no change or improvement in their best corrected visual acuity; in the undercorrected group, 89% showed no change or improvement.

CONCLUSIONS

Laser in situ keratomileusis was relatively safe in treating both overcorrection and undercorrection after RK. With proper intraoperative precautions, LASIK can effectively treat the residual refractive defects after RK.

Corneal Sensitivity and Some Properties of the Tear Film After Laser in situ Keratomileusis

PURPOSE

To investigate central corneal sensitivity, lipid layer structure of the precorneal tear film, and tear volume after laser in situ keratomileusis (LASIK).

METHODS

Central corneal sensitivity was measured using the Non-Contact Corneal Aesthesiometer. The aesthesiometer was mounted on a slit lamp and an airpulse of controlled pressure was directed onto the cornea. When central corneal sensitivity was reduced, a higher air pulse pressure was required to stimulate the cornea. The final central corneal sensitivity threshold measured was recorded in millibars. Tear lipid layer structure was assessed by optical interferometry and classified according to appearance using the Keeler Tearscope. Tear volume was measured using the phenol red cotton thread test. Subjects were recruited from a group of patients after LASIK who had experienced no complications (n=22). The average postoperative time was 14 weeks and measurements were taken on one eye. In bilateral cases, measurements were recorded from the right eye only. Average attempted correction was -6.30 D (range, -2 to -11 D). Age-matched controls were later recruited for central corneal sensitivity threshold (n=24). A second group of age-matched controls were recruited for tear volume and lipid layer structure (n=24).

RESULTS

The median (range) was 1.1 mbars (0.2 to 4.3 mbars) after LASIK and 0.58 mbars (0.20 to 1.3 mbars) in the controls; the difference was statistically significant (P = .043). The lipid layer of the tear film tended to be thinner in eyes after LASIK compared with controls (P = .032). The mean (+/- SD) tear volume was 16.9 +/- 8.3 mm after LASIK and 19.8 +/- 7.1 mm in controls. This difference was not statistically significant (P = .492).

CONCLUSION

At 14 weeks postoperatively, central corneal sensitivity was below normal levels and the tear lipid layer was thinner. The poorer quality lipid layer may predispose to symptoms of dry eye after LASIK.

Laser in situ Keratomileusis to Correct Residual Myopia After Cataract Surgery

PURPOSE

To evaluate the effectiveness, predictability, and safety of laser in situ keratomileusis (LASIK) for correcting residual myopia after cataract surgery with intraocular lens implantation.

METHODS

Twenty-two eyes of 22 patients underwent LASIK for the correction of residual myopia after cataract surgery. LASIK was carried out using the Chiron Automated Corneal Shaper and the NIDEK EC-5000 excimer laser. In all eyes, the follow-up was 12 months.

RESULTS

Before LASIK, 1 eye (4.5%) had an uncorrected visual acuity of 0.5 or better; 12 months after LASIK, 10 eyes (45.4%) achieved this level of visual acuity and 0 eyes achieved 1.00 or better. Before LASIK, mean refraction was -2.90 +/- 1.80 D; 12 months after LASIK it decreased significantly to 0.40 +/- 0.60 D (P < .01). In 18 eyes (81.8%) at 12 months after LASIK, spherical equivalent refraction was within +/-1.00 D of emmetropia; 11 eyes (50%) were within 0.50 D. No vision-threatening complications occurred.

CONCLUSION

LASIK with the Automated Corneal Shaper and Nidek EC-5000 excimer laser was an effective, predictable, stable, and safe procedure for correcting residual myopia after cataract surgery. No intraocular lens or cataract incision related complications occurred when LASIK was performed at least 3 months after phacoemulsification.

Laser in situ keratomileusis flap margin: wound healing and complications imaged by in vivo confocal microscopy

PURPOSE

To examine the healing response of laser in situ keratomileusis flap margin in vivo.

METHODS

Forty-three eyes of 43 patients who had undergone myopic (n = 39) or hyperopic (n = 4) laser in situ keratomileusis were examined once after surgery. The flap margin was imaged by in vivo confocal microscopy at various depths, and the wound healing response, flap alignment, and complications were evaluated. Ten eyes were examined on day 3 postoperatively, 13 eyes at 1 to 2 weeks, 10 eyes at 1 to 2 months, five eyes at 3 months, and five eyes at 6 months or later.

RESULTS

At 3 days after laser in situ keratomileusis, the surface epithelium and basal epithelium appeared normal. Keratocyte activation was strongest at 1 to 2 weeks and 1 to 2 months, and an increased amount of haze was observed correspondingly. Intrastromal epithelial cells forming a plug could occasionally be perceived in the wound gape. Wound constriction was completed in most cases by 3 to 6 months or later. Good alignment was observed in 12 of 43 flaps (27.9%) and moderate and poor alignment in 17 of 43 flaps (39.5%) and 13 of 43 flaps (30.2%), respectively. Poor alignment was not associated with lamellar epithelial ingrowth. Epithelial ingrowth was associated with dense haze at the interface. Diffuse lamellar keratitis was imaged in two corneas after hyperopic laser in situ keratomileusis.

CONCLUSIONS

The laser in situ keratomileusis incision wound at the flap margin appears to heal after the sequence observed in incisional wounds in nonhuman primates. Complications, such as lamellar epithelial in growth and diffuse lamellar keratitis, were often observed, particularly after hyperopic laser in situ keratomileusis.

Choroidal neovascularization in myopic eyes after photorefractive keratectomy

PURPOSE

To evaluate the incidence, characteristics, and results of treatment of choroidal neovascularization (CNV) in myopic eyes corrected by photorefractive keratectomy (PRK).

SETTING

University Miguel Hernández, Instituto Oftalmológico de Alicante, Alicante, Spain.

METHODS

This study was of the incidence of CNV in 5936 consecutive eyes that had PRK for the correction of myopia. Mean follow-up was 38.5 months +/- 17.4 (SD).

RESULTS

Extrafoveal CNV developed in the right eye of a 44-year-old woman 26 months after PRK for the correction of -12.00 diopters (D) of myopia. The follow-up after PRK was 38 months. Best corrected visual acuity (BCVA) before PRK was 20/40 (spherical equivalent [SE] -12.00 D). After PRK, BCVA was 20/32 SE -1.75 D). The CNV was treated by direct argon-green laser photocoagulation and did not recur in the subsequent 12 months). After CNV treatment, BCVA was 20/32 (SE -2.25 D).

CONCLUSION

The incidence of CNV after PRK for myopia was low. Choroidal neovascularization is a possible complication in myopic eyes, and the risk exists before PRK. After PRK, the risk of CNV in myopic patients did not increase.

Cataract surgery in highly myopic eyes corrected by phakic anterior chamber angle-supported lenses(1)

PURPOSE

To assess the incidence of cataract, potential causes of its development, and the outcome of cataract surgery after previous implantation of phakic angle-supported anterior chamber intraocular lenses (AC IOLs) in highly myopic patients.

SETTING

Instituto Oftalmológico de Alicante, Department of Refractive Surgery, Spain.

METHODS

Two hundred sixty-three highly myopic phakic eyes of 160 patients had implantation of a phakic AC IOL. Follow-up was up to 8 years (range 38.4 to 103.2 months). Eyes that subsequently developed cataract had cataract extraction and were studied during follow-up for clinical association to other preoperative or postoperative data. Cataract surgery was performed after phakic IOL explantation by phacoemulsification and posterior chamber IOL (PC IOL) implantation (Domilens-Chiron AL3).

RESULTS

Nuclear cataract developed in 9 cases (3.42%) a mean of 42.91 months +/- 17.7 (SD) after phakic AC IOL implantation. Final best spectacle-corrected visual acuity (BSCVA) was not significantly different from that after phakic AC IOL implantation (P =.25, paired Student t test). Mean endothelial cell loss after cataract surgery was 6.87% +/- 0.42% cells/mm(2). Age at implantation of older than 40 years and axial length greater than 30. 0 mm were the 2 factors significantly related to nuclear cataract development (r = 1.69 and 1.98, respectively; P <.05).

CONCLUSIONS

There is a potential risk of nuclear cataract development after phakic AC IOL implantation to correct high myopia in patients older than 40 years and with very high (greater than 30.0 mm) axial myopia. Phakic IOL explantation, phacoemulsification, and PC IOL implantation successfully resolved this complication. The benefits in terms of BSCVA and spherical equivalent obtained after phakic AC IOL implantation were preserved after cataract surgery.

Surgical correction of severe myopia with an angle-supported phakic intraocular lens

PURPOSE

To evaluate the effectiveness, predictability, and safety of a fourth-generation angle-supported anterior chamber phakic intraocular lens (IOL) in patients with severe myopia.

SETTING

Refractive Surgery and Cornea Unit, Alicante Institute of Ophthalmology, Miguel Hernández University School of Medicine, Alicante, Spain.

METHODS

In this prospective study, 23 eyes (16 patients) with a mean preoperative myopia of -19.56 diopters (D) +/- 1.76 (SD) (range -16.75 to -23.25 D) were implanted with the ZSAL-4 phakic IOL. Basic examinations were performed before and after surgery in all patients. Eighteen eyes were also studied by clinical specular microscopy, and the endothelium was analyzed for cell density, coefficient of variation in cell size, and hexagonality. The location of the IOL in the anterior chamber was evaluated in 10 eyes by A-scan biometry. To evaluate haptic geometry, a theoretical mechanical model was used. The follow-up was 24 months in all patients.

RESULTS

Uncorrected visual acuity was 20/40 or better in 13 eyes (56.0%) 12 months after surgery and in 14 eyes (60.8%) at 24 months. Best spectacle-corrected visual acuity improved 0.19 at 12 and 24 months (0.1 = 1 line) from preoperative values. The efficacy index was 1.12 at 24 months and the safety index, 1.45. The mean postoperative spherical equivalent was -0.65 +/- 0.65 D at 24 months. The postoperative spherical equivalent was within +/-1.00 D of emmetropia in 19 eyes (82.6%) at 12 and 24 months. The mean endothelial cell loss was 3.50% at 12 months and 4.18% at 24 months. The coefficient of variation in cell size decreased from 0.34 before surgery to 0.28 at 24 months after surgery. The IOL was located 0.79 +/- 0.24 mm in front of the crystalline lens. Postoperative complications included night halos in 6 eyes (26.1%) at 12 and 24 months and pupil ovalization in 4 eyes (17.4%). Intraocular lens rotation was observed in 10 eyes (43.5%) at 24 months. Two eyes (8. 7%) developed a slight inflammatory response during the first 6 months. Our mechanical model predicted that the compression forces against the angle structures were greater at the first footplate than at the second.

CONCLUSIONS

Implantation of the ZSAL-4 IOL in the anterior chamber of phakic eyes was effective and predictable in correcting severe myopia. However, the ZSAL-4 did not prevent pupil ovalization, IOL rotation, or low-grade postoperative uveitis. Improvements in haptic design following our mechanical model could decrease these haptic-related complications.

Postoperative Inflammation, Microbial Complications, and Wound Healing Following Laser in situ Keratomileusis

Although the biology of corneal wound healing is only partly understood, healing after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) differs in many respects, and the mechanisms appear to be differently controlled. There is less of an inflammatory and healing response after LASIK, but a longer period of sensory denervation. The cellular, molecular, and neural regulatory phenomena associated with postoperative inflammation and wound healing are likely to be involved in the adverse effects after LASIK, such as flap melt, epithelial ingrowth, and regression. Interface opacities in the early postoperative period include diffuse lamellar keratitis (DLK), microbial keratitis, epithelial cells, and interface opacities. Diffuse lamellar keratitis (sands of the Sahara syndrome) describes an apparently noninfectious diffuse interface inflammation after lamellar corneal surgery probably caused by an allergic or a toxic inflammatory reaction. Noninfectious keratitis must be distinguished from microbial keratitis to avoid aggressive management and treatment with antimicrobial drugs. Microbial keratitis is a serious complication after LASIK, but a good visual outcome can be achieved following prompt and appropriate treatment.

[Contrast sensitivity after laser in situ keratomileusis for myopia (LASIK-M)]

PURPOSE

To evaluate the effect of laser in situ keratomileusis for the correction of moderate myopia (LASIK) on contrast sensitivity values.

METHODS

Seventeen eyes of 10 patients underwent LASIK to correct myopia ranging from 7.75 to -4.75 D (mean +/- SD, -6.53 +/- 0.99 D). Contrast sensitivity was tested preoperatively and 1, 3, 6 and 12 months postoperatively using the CVS -1000 contrast sensitivity test (Vector Vision).

RESULTS

Contrast sensitivity decreased in the first postoperative month, the decrease was significant for 6 dg and 12 c/g (P -0.006 and P=0.005, respectively). At 3 months it returned to preoperative values although it was not statistically significant (P>0.05). There was an improvement at 6 months at spatial frequencies of 3 c/g and 6 c/g and at 12 months the improvement was for 3, 6 and 18 c/g, although the changes were not significant.

CONCLUSION

Although LASIK decreased contrast sensitivity values at one month after surgery, these values returned to the preoperative levels at 3 months. The improvement at certain frequencies at 6 and 12 months suggests that LASIK can improve the quality of vision in eyes with low to moderate myopia.

Selective zonal ablations with excimer laser for correction of irregular astigmatism induced by refractive surgery

OBJECTIVE

To demonstrate the safety and efficacy of selective zonal ablations with excimer laser for the correction of irregular astigmatism induced by refractive surgery.

DESIGN

Thirty-one eyes of 26 patients. Retrospective and noncomparative case series.

METHODS

The authors reviewed the medical results of the two series of consecutive cases of irregular astigmatism induced by refractive surgery. One group showed a topography map with a defined pattern: decentered ablation, decentered steep central island, central irregularity, and peripheral irregularity. The other group showed an irregular astigmatism without defined pattern. Selective zonal ablation was performed with a broad-beam excimer laser. Laser ablations were adjusted according to the Munnerlyn formula. A phototherapeutic keratectomy (PTK) mode was used in all cases without using viscous masking solution.

MAIN OUTCOME MEASURES

Uncorrected visual acuity, best spectacle-corrected visual acuity (BCVA), and Holladay diagnostic summary (Eye Sys 2.000) were considered before and after surgery to obtain the qualitative and quantitative characteristics of the visual acuity and corneal topography. The corneal uniformity index (CUI) was used to evaluate the corneal surface changes induced by the selective zonal ablations in the correction of irregular astigmatism. It proved to be a useful tool in the understanding of astigmatic changes when it is not possible to apply the vector analysis.

RESULTS

In group 1, the irregular astigmatism was significantly improved in 96.4% of cases. The CUI was improved from 58+/-0.3% to 87+/-0.8%, P < 0.005 (Student's t-test). The improvement of the BCVA was from 20/40+/-20/100 to 20/25+/-20/100, P < 0.005 (Student's t-test). The results obtained in group 2 were not clinically significant in terms of improvement of CUI and BCVA.

CONCLUSIONS

Using the corneal topographic map as a guide, selective zonal ablations with excimer laser can be used to create a more regular corneal surface, when a defined pattern of topographic irregularities can be defined.

Laser in situ Keratomileusis for Recurrent Hyperopia Following Laser Thermal Keratoplasty

PURPOSE

Laser thermal keratoplasty (LTK) has its main indication in the correction of hyperopia. However, regression of refractive effect following LTK is a limitation. Laser in situ keratomileusis (LASIK) may provide a good alternative to correct residual refractive errors.

METHODS

Fifty hyperopic eyes with varying amounts of regression after LTK underwent LASIK. The Chiron Automated Corneal Shaper microkeratome was used to make a flap of 160 microm and laser ablation was performed with the Technolas 217 Planoscan excimer laser. Postoperative follow-up was 6 months.

RESULTS

Mean spherical equivalent refraction improved from +2.92+/-1.60 D to +0.36+/-1.48 D. Mean best spectacle-corrected visual acuity changed from 0.78+/-0.14 before LASIK to 0.76+/-0.16 D 6 months after LASIK. Mean uncorrected visual acuity changed from 0.37+/-0.16 to 0.66+/-0.24. Forty-two percent (21 eyes) were within +/-0.50 D of intended correction, 60% (30 eyes) were within +/-1.00 D, and 76% (38 eyes) were within +/-2.00 D. After LASIK, confluent haze between previous LTK spots was observed in most eyes, as LASIK ablation took place at the sites of the LTK spots.

CONCLUSIONS

LASIK after LTK is a good alternative for hyperopic regression. Predictability and efficacy are less than with primary LASIK for hyperopia, but the procedure is equally safe.

Retinal detachment in myopic eyes after photorefractive keratectomy

PURPOSE

To analyze the incidence and characteristics of retinal detachment (RD) in myopic patients who had photorefractive keratectomy (PRK).

SETTING

Universidad Miguel Hernández, Instituto Oftalmológico de Alicante, Alicante, Spain.

METHODS

The incidence of RD in 5936 consecutive eyes that had PRK to correct myopia was studied. Mean follow-up was 38.5 months +/- 17.4 (SD).

RESULTS

Retinal detachment occurred in 5 eyes (0.08%); 2 in women and 3 in men. The mean interval between PRK and RD was 21. 00 +/- 15.89 months (range 9 to 48 months). The mean best corrected visual acuity (BCVA) after PRK and before RD development was 20/81 (range 20/200 to 20/25). After RD repair, the mean BCVA was 20/460 (range 20/2000 to 20/29). In 4 of the 5 eyes, BCVA after RD was within 1 line of the preoperative value; in 1 eye, it decreased from 20/40 to 20/2000. The mean spherical equivalent (SE) before RD treatment was -1.35 +/- 1.08 diopters (D) (range 0 to -3.00 D) and after RD treatment, -2.95 +/- 0.83 D (range -2.00 to -4.00 D). Differences between SE before and after RD treatment were statistically significant (P =.01, paired Student t test).

CONCLUSIONS

The incidence of RD after PRK to correct myopia was 0.08%. In 4 of 5 eyes, there was little or no visual loss; but in the group as a whole, there was a significant increase in myopic SE.

Effect of myopic LASIK on corneal sensitivity and morphology of subbasal nerves

PURPOSE

To investigate whether the morphology of the subbasal nerves corresponds to corneal sensitivity after laser in situ keratomileusis (LASIK).

METHODS

In a case series study, 59 patients were examined at 2 to 4 hours, 3 days, 1 to 2 weeks, 1 to 2 months, 3 months, or 6 or more months after undergoing LASIK for myopia, by using a Cochet-Bonnet esthesiometer and an in vivo confocal microscope, and were compared with control subjects. Corneal sensitivity and confocal images of subbasal nerves were obtained centrally and 2 mm nasally and temporally. Subbasal nerve fiber bundles (NFBs) were grouped as follows: corneas with no nerve images; corneas with short (<200 microm), unconnected NFBs; corneas with long (> or =200 microm) NFBs without interconnections; and corneas with long NFBs with interconnections.

RESULTS

Corneal sensitivity was at its lowest at 1 to 2 weeks after LASIK. Sensitivity of the hinge area was higher than temporal or central areas at every time point. At 6 or more months the sensitivity values were comparable with the values observed in control subjects. The central area showed mainly short, unconnected subbasal NFBs, even at 6 months. In general, the temporal area presented with long NFBs from 3 months onward, whereas the nasal area showed long NFBs at every time point.

CONCLUSIONS

The results suggest that the corneal areas with no nerve images or short, unconnected NFBs are associated with lower sensitivities than corneal areas with long NFBs with or without interconnections. In vivo confocal microscopy reveals LASIK-induced alterations of subbasal nerve morphology and thus enables a direct comparison of corneal sensory innervation and sensitivity.

Successful treatment of severe wrinkled corneal flap after laser in situ keratomileusis with deionized water

PURPOSE

To investigate a case of severe wrinkled corneal flap after laser in situ keratomileusis (LASIK) successfully treated by hydrating the flap with deionized water and applying a bandage contact lens.

METHODS

A 39-year-old woman presented with corneal flap wrinkles 24 hours after undergoing LASIK in her left eye. Under the operating microscope the flap was refloated and hydrated with sterile deionized water for 2 minutes without stretching or ironing the flap. A bandage contact lens was then applied for 24 hours. Sterile deionized water was used topically every 2 hours for 1 day.

RESULTS

Twenty-four hours after treatment with sterile deionized water and a bandage contact lens, the cornea was smooth and wrinkle free.

CONCLUSIONS

Hydration with deionized water may offer advantages over isotonic solutions in treating a wrinkled corneal flap after LASIK.

Retinal detachment in myopic eyes after laser in situ keratomileusis

PURPOSE

To analyze the incidence and characteristics of retinal detachment in myopic patients treated by laser-assisted in situ keratomileusis.

METHODS

We retrospectively studied the retinal detachments observed in 1,554 consecutive eyes (878 patients) undergoing laser-assisted in situ keratomileusis for the correction of myopia (follow-up, 30.34+/-10.27 months; range, 16 to 54). Mean patient age was 33.09+/-8.6 years (range, 20 to 60). Before treatment with laser-assisted in situ keratomileusis, all patients had a comprehensive examination, and detected lesions predisposing to retinal detachment were treated before performing the laser-assisted in situ keratomileusis procedure.

RESULTS

Retinal detachment occurred in four (0.25%) of 1,554 eyes of four (0.45%) of 878 patients. All four patients who developed retinal detachment in one eye were women. Degree of preoperative myopia was -13.52+/-3.38 diopters (range, -8.00 to -27.50). The time interval between refractive surgery and retinal detachment was 11.25+/-8.53 months (range, 2 to 19 months). In all cases retinal detachment was spontaneous. In all eyes the retina was reattached successfully at the first retinal detachment surgery. Mean best-corrected visual acuity after laser-assisted in situ keratomileusis and before retinal detachment development was 20/43 (range, 20/50 to 20/30). After retinal detachment repair, best-corrected visual acuity was 20/45 (range, 20/50 to 20/32). Differences between best-corrected visual acuity before and after reattachment were not statistically significant (P = .21, paired Student t test). A myopic shift was induced in three eyes that had retinal detachment repaired by scleral buckling, from -0.58+/-0.72 diopter (range, +0.25 to -1.00) before retinal detachment and -2.25+/-1.14 diopters (range, -1.00 to -3.25) after retinal detachment surgery (P = .03, paired Student t test).

CONCLUSIONS

Laser-assisted in situ keratomileusis for correction of myopia is followed by a low incidence of retinal detachment. Conventional scleral buckling surgery was successful in most cases and did not cause significant changes in the final best-corrected visual acuity. A significant increase in the myopic spherical equivalent was observed after scleral buckling in these patients.