Ioannis M Aslanides

Intacs for early pellucid marginal degeneration

A 42-year-old man had Intacs (Addition Technology Inc.) implantation for early pellucid marginal degeneration (PMD). Two Intacs segments (0.45 mm thickness) were inserted uneventfully in the fashion typically used for low myopia correction (nasal-temporal). Eleven months after the procedure, the uncorrected visual acuity was 20/200, compared with counting fingers preoperatively, while the best spectacle-corrected visual acuity improved to 20/25 from 20/50. Corneal topographic pattern also improved. Although the results are encouraging, concern still exists regarding the long-term effect of this approach for the management of patients with PMD.

The effect of static cyclotorsion compensation on refractive and visual outcomes using the Schwind Amaris laser platform for the correction of high astigmatism

PURPOSEnTo compare the refractive and visual outcomes using the Schwind Amaris excimer laser in patients with high astigmatism (>1D) with and without the static cyclotorsion compensation (SCC) algorithm available with this new laser platform.nnnMETHODSn70 consecutive eyes with ≥1D astigmatism were randomized to treatment with compensation of static cyclotorsion (SCC group- 35 eyes) or not (control group- 35 eyes). A previously validated optimized aspheric ablation algorithm profile was used in every case. All patients underwent LASIK with a microkeratome cut flap.nnnRESULTSnThe SCC and control group did not differ preoperatively, in terms of refractive error, magnitude of astigmatism or in terms of cardinal or oblique astigmatism. Following treatment, average deviation from target was SEq +0.16D, SD±0.52 D, range -0.98 D to +1.71 D in the SCC group compared to +0.46 D, SD±0.61 D, range -0.25 D to +2.35 D in the control group, which was statistically significant (p<0.05). Following treatment, average astigmatism was 0.24 D (SD±0.28 D, range -1.01 D to 0.00 D) in the SCC group compared to 0.46 D (SD±0.42 D, range -1.80 D to 0.00 D) in the control group, which was highly statistically significant (p<0.005). There was no statistical difference in the postoperative uncorrected vision when the aspheric algorithm was used although there was a trend to increased number of lines gained in the SCC group.nnnCONCLUSIONSnThis study shows that static cyclotorsion is accurately compensated for by the Schwind Amaris laser platform. The compensation of static cyclotorsion in patients with moderate astigmatism produces a significant improvement in refractive and astigmatic outcomes than when not compensated.

Corneal perforation after conductive keratoplasty with previous refractive surgery

A 56-year-old woman had conductive keratoplasty (CK) for residual hyperopia and astigmatism. Three years before the procedure, the patient had arcuate keratotomy, followed by laser in situ keratomileusis 2 years later for high astigmatism correction in both eyes. During CK, a corneal perforation occurred in the right eye; during the postoperative examination, an iris perforation and anterior subcapsule opacification were seen beneath the perforation site. The perforation was managed with a bandage contact lens and an antibiotic-steroid ointment; it had a negative Seidel sign by the third day. The surgery in the left eye was uneventful. Three months after the procedure, the uncorrected visual acuity was 20/32 and the best corrected visual acuity 20/20 in both eyes with a significant improvement in corneal topography. Care must be taken to prevent CK-treated spots from coinciding with areas in the corneal stroma that might have been altered by previous refractive procedures.

Bilateral nasolabial cysts associated with recurrent dacryocystitis

OBJECTIVEnNasolabial cysts are rare, nonodontogenic, soft-tissue, developmental cysts occurring inferior to the nasal alar region. They are thought to arise from remnants of the nasolacrimal ducts and they are frequently asymptomatic. We report a rare case of bilateral nasolabial cysts accompanied by bilateral chronic dacryocystitis.nnnCASE REPORTnA 48-year-old woman suffering from bilateral chronic dacryocystitis was referred to our department for endonasal dacryocystorhinostomy. She had undergone external dacryocystorhinostomy on the left side a few years earlier. Physical examination and computed tomography scan revealed nasolabial cysts bilaterally inferior to the nasal alar region. The cysts were removed via a sublabial approach and endoscopic dacryocystorhinostomy was performed on the right side. Ten months after surgery, the patient was asymptomatic.nnnCONCLUSIONnThere may be a correlation, due to embryological reasons, between the presence of nasolabial cysts and the presence of chronic dacryocystitis. Both can be corrected surgically, under the same anaesthesia, without visible scar formation.

Laser in situ keratomileusis for residual hyperopic astigmatism after conductive keratoplasty.

PURPOSEnTo report a case of laser in situ keratomileusis (LASIK) in a patient with previous conductive keratoplasty.nnnMETHODSnA 48-year-old man underwent conductive keratoplasty for low hyperopic astigmatism (manifest refraction OD: +2.25 -0.50 x 77 degrees; OS: +2.50 -0.50 x 105 degrees). Three months postoperatively, UCVA was 20/25 and BSCVA was 20/20 in both eyes; manifest refraction OD: -0.25 -0.75 x 110 degrees; OS: +0.75 -0.75 x 50 degrees. Sixteen months after the operation, regression of refractive outcome was (manifest) OD: +1.75 -1.25 x 90 degrees; OS: +2.50 -0.50 x 85 degrees; UCVA was 20/40 in the right eye and 20/63 in the left eye and BSCVA was 20/20 in both eyes. LASIK was performed for hyperopic regression in the left eye using an automated microkeratome (Alcon SKBM, 130-microm plate; Aesculap-Meditec MEL 70 excimer laser).nnnRESULTSnLASIK was uneventful and no intraoperative or postoperative complications related to the previous conductive keratoplasty procedure or LASIK were observed. Three months after LASIK and 19 months after the initial conductive keratoplasty, the patients left eye was emmetropic; UCVA was 20/20(-2), BSCVA was 20/20 and manifest refraction was +0.25 -0.25 x 35 degrees. There was a uniform increase in topographical steepening. Visual acuity, refraction and topographic findings remained unchanged at 6 months.nnnCONCLUSIONSnEven though our experience is limited, treatment of hyperopia with LASIK in an eye with refractive regression following previous conductive keratoplasty resulted in a predicted refractive outcome, with no complications, and improvement in visual acuity at 6 months follow-up.

Corneal iron ring after conductive keratoplasty

PURPOSEnTo report formation of corneal iron ring deposits after conductive keratoplasty.nnnDESIGNnObservational case report.nnnMETHODSnCase report.nnnRESULTSnA 54-year-old woman underwent conductive keratoplasty for hyperopia. One year after conductive keratoplasty, iron ring pattern pigmentation was detected at the corneal epithelium of both eyes.nnnCONCLUSIONSnThis is the first report of the appearance of corneal iron ring deposits following conductive keratoplasty treatment in a patient. It is suggested that alterations in tear film stability, resulting from conductive keratoplasty-induced changes in corneal curvature, constitute the contributory factor for these deposits.

Intraocular Pressure Measurements After Conductive Keratoplasty

PURPOSEnTo determine the possible impact of conductive keratoplasty (CK) on intraocular pressure (IOP) measurements.nnnMETHODSnA prospective, single-center, noncomparative interventional case series was performed. Baseline and postoperative IOPs were measured by Goldmann applanation tonometry in 32 eyes of 18 patients who underwent CK for hyperopia correction. Mean follow-up was 11.9 months (range: 8 to 18 months).nnnRESULTSnAfter CK, a statistically significant decrease in the measured IOP was observed (before CK: 14.22+/-1.64 vs after CK: 12.66+/-2.21, P<.001). The change in IOP readings postoperatively was not correlated with age, sex, keratometric readings, or attempted correction.nnnCONCLUSIONSnDespite the limitations due to the small number of patients enrolled in this study, the applanation tonometer appears to underestimate the true IOP after CK.

RADAR: A novel fast-screening method for reading difficulties with special focus on dyslexia

Dyslexia is a developmental learning disorder of single word reading accuracy and/or fluency, with compelling research directed towards understanding the contributions of the visual system. While dyslexia is not an oculomotor disease, readers with dyslexia have shown different eye movements than typically developing students during text reading. Readers with dyslexia exhibit longer and more frequent fixations, shorter saccade lengths, more backward refixations than typical readers. Furthermore, readers with dyslexia are known to have difficulty in reading long words, lower skipping rate of short words, and high gaze duration on many words. It is an open question whether it is possible to harness these distinctive oculomotor scanning patterns observed during reading in order to develop a screening tool that can reliably identify struggling readers, who may be candidates for dyslexia. Here, we introduce a novel, fast, objective, non-invasive method, named Rapid Assessment of Difficulties and Abnormalities in Reading (RADAR) that screens for features associated with the aberrant visual scanning of reading text seen in dyslexia. Eye tracking parameter measurements that are stable under retest and have high discriminative power, as indicated by their ROC (receiver operating characteristic) curves, were obtained during silent text reading. These parameters were combined to derive a total reading score (TRS) that can reliably separate readers with dyslexia from typical readers. We tested TRS in a group of school-age children ranging from 8.5 to 12.5 years of age. TRS achieved 94.2% correct classification of children tested. Specifically, 35 out of 37 control (specificity 94.6%) and 30 out of 32 readers with dyslexia (sensitivity 93.8%) were classified correctly using RADAR, under a circular validation condition (see section Results/Total Reading Score) where the individual evaluated was not included in the test construction group. In conclusion, RADAR is a novel, automated, fast and reliable way to identify children at high risk of dyslexia that is amenable to large-scale screening. Moreover, analysis of eye movement parameters obtained with RADAR during reading will likely be useful for implementing individualized treatment strategies and for monitoring objectively the success of chosen interventions. We envision that it will be possible to use RADAR as a sensitive, objective, and quantitative first pass screen to identify individuals with reading disorders that manifest with abnormal oculomotor reading strategies, like dyslexia.

Assessment of UVA-Riboflavin Corneal Cross-Linking Using Small Amplitude Oscillatory Shear Measurements.

PURPOSEnThe effect of ultraviolet (UV)-riboflavin cross-linking (CXL) has been measured primarily using the strip extensometry technique. We propose a simple and reliable methodology for the assessment of CXL treatment by using an established rheologic protocol based on small amplitude oscillatory shear (SAOS) measurements. It provides information on the average cross-link density and the elastic modulus of treated cornea samples.nnnMETHODSnThree fresh postmortem porcine corneas were used to study the feasibility of the technique, one serving as control and two receiving corneal collagen cross-linking treatment. Subsequently, five pairs of fresh postmortem porcine corneas received corneal collagen cross-linking treatment with riboflavin and UVA-irradiation (370 nm; irradiance of 3 mW/cm2) for 30 minutes (Dresden protocol); the contralateral porcine corneas were used as control samples. After the treatment, the linear viscoelastic moduli of the corneal samples were measured using SAOS measurements and the average cross-linking densities extracted.nnnRESULTSnFor all cases investigated, the dynamic moduli of the cross-linked corneas were higher compared to those of the corresponding control samples. The increase of the elastic modulus of the treated samples was between 122% and 1750%. The difference was statistically significant for all tested samples (P = 0.018, 2-tailed t-test).nnnCONCLUSIONSnWe report a simple and accurate methodology for quantifying the effects of cross-linking on porcine corneas treated with the Dresden protocol by means of SAOS measurements in the linear regime. The measured dynamic moduli, elastic and viscous modulus, represent the energy storage and energy dissipation, respectively. Hence, they provide a means to assess the changing physical properties of the cross-linked collagen networks after CXL treatment.

Phacoemulsification and Implantation of an Accommodating IOL After PRK

PURPOSEnTo present a case of phacoemulsification and implantation of an accommodating intraocular lens (IOL) in a patient with cataract formation after previous refractive surgery.nnnMETHODSnA 50-year-old man, who initially had photorefractive keratectomy to correct moderate myopia, developed a cataract in one eye. He subsequently underwent phacoemulsification and implantation of a 1CU accommodating IOL, as he wished to remain spectacle independent.nnnRESULTSnThe patients distance vision was fully restored. However, accommodative function, which was assessed using subjective and novice objective techniques, was only partially restored.nnnCONCLUSIONSnAlthough the accommodating IOL fully restored the patients distance vision, accommodative function was only partially restored.