George Kontadakis

Effect of blur and subsequent adaptation on visual acuity using letter and Landolt C charts: differences between emmetropes and myopes

To compare the effects of defocus induced blur and blur adaptation on visual acuity and to evaluate any differences between emmetropes and myopes using letter and Landolt C logMAR charts.

Long Term Followup of Photorefractive Keratectomy with Adjuvant Use of Mitomycin C

Purpose. To study the long term refractive and visual outcomes of photorefractive keratectomy (PRK) with intraoperative application of mitomycin C (MMC). Methods. This study included 37 eyes who received myopic PRK; after photoablation, a sponge soaked in 0.02% MMC solution was applied in all corneas for 2 minutes. Efficacy, safety, predictability, and stability of PRK MMC were evaluated. Endothelial cell density was evaluated at the last postoperative interval. Results. Mean preoperative spherical equivalent (SEQ) was −6.03 ± 1.87 D (diopters) and reduced to −0.09 ± 0.53 D at the last postoperative examination. Mean followup was 44.73 ± 18.24 months. All the eyes were in the ±1.00 D of attempted versus achieved SEQ at the one-year follow-up interval. Furthermore, 95% of the eyes did not lose lines or gained 1 to 2 lines of CDVA, while 5% lost 1 line. At the third postoperative month, 89% of the eyes either were clear or had trace haze, while 4 eyes had mild haze; by the 12-month postoperative interval, none of the eyes demonstrated haze. Mean endothelial cell density (ECD) at the last postoperative interval was 2658 ± 153 cells/mm2. Conclusions. PRK, with intraoperative use of MMC, demonstrates stable refractive and visual outcomes up to 44 months after surgery.

Treatment of superior limbic keratoconjunctivitis with topical tacrolimus 0.03% ointment.

Purpose: To report 2 cases of superior limbic keratoconjunctivitis (SLK) treated with topical tacrolimus 0.03% ointment (Protopic; Fujisawa Healthcare). Methods: A female patient aged 52 years and a male patient aged 21 years presented with SLK in both eyes. Both patients had previously received several treatments [such as topical steroids and lubrication, contact lenses, silicone punctal plugs, and vitamin A eye drops], with no improvement. Because of poor response to initial management, the authors started treatment with topical tacrolimus 0.03% twice a day. Objective tarsal conjunctiva inflammation, bulbar conjunctiva findings (such as hyperemia and thickening), cornea staining, and subjective symptoms were evaluated. Results: A week later, both patients were symptomatically better. Four weeks after treatment initiation, the signs of thickened and hyperemic superior conjunctiva, papillary reaction, and punctate keratopathy were almost resolved. Tacrolimus was successfully tapered in both the patients. There were no side effects. Conclusions: Topical tacrolimus 0.03% ointment may be considered an additional treatment option for SLK.

Topography-based keratoconus progression after corneal collagen crosslinking.

Purpose: The aim of this study was to report 2 cases with topographic keratoconus progression despite stability for a long-term period after corneal collagen crosslinking (CXL). Methods: This is a case report. Results: Two patients with progressive keratoconus underwent CXL treatment. Four and 5 years postoperatively, a topographic examination revealed an increase in the keratometric values indicating keratoconus progression. Conclusions: Post-CXL, topographic keratoconus progression may occur several years after, despite stability for a long-term period.

Comparison of visual acuity charts in young adults and patients with diabetic retinopathy.

Purpose To compare visual acuity (VA) assessed in healthy eyes and eyes with diabetic retinopathy (DR) using three different logMAR charts: the Sloan letter European-wide chart, the tumbling E chart, and the Landolt C chart. Methods Measurements on one eye of 40 volunteers (aged 29 ± 4 years) without visual impairment and 31 DR patients (aged 70 ± 9 years) with mild/moderate visual impairment were included. Visual acuity was assessed, with habitual refractive correction, using each of the three charts. Bland-Altman charts were constructed, and 95% limits of agreement were calculated to measure agreement. Results Mean VA in the group of young adults was −0.05 ± 0.10 (Sloan letter), −0.02 ± 0.13 (tumbling E), and 0.00 ± 0.12 (Landolt C) logMAR. Average VA estimates differed to a statistically significant extent between all charts. Mean VA in the DR group was 0.46 ± 0.25 (Sloan letter), 0.48 ± 0.26 (tumbling E), and 0.59 ± 0.28 (Landolt C). A statistically significant difference was observed for average Sloan letter versus Landolt C (p < 0.001) and tumbling E versus Landolt C (p < 0.001) acuities. Moreover, in healthy eyes, a moderate correlation (r = −0.38, p = 0.015) was found between the discrepancy in Sloan letter and Landolt C acuity and the mean VA estimate. The 95% limits of agreement were wide (more than approximately 0.2 logMAR for each comparison) and wider in the DR group chart comparisons than in healthy eyes. Conclusions Landolt C charts resulted in worse VA estimates compared with letter and tumbling E charts in both young adults and visually impaired subjects with DR. These differences seem more pronounced in DR patients who exhibit worse VAs. The specific study population must be considered in comparing outcomes from different clinical practices.

Accelerated versus conventional corneal crosslinking for refractive instability: an update

Purpose of review Corneal crosslinking (CXL) is a relatively new treatment modality offering refractive stability in patients with ectatic disorders. The procedure as initially described (Dresden protocol) is time consuming; accelerated protocols have been lately developed. The purpose of this review is to present the recent findings regarding the comparison of accelerated CXL with the conventional Dresden protocol. Recent findings A variety of accelerated protocols are described in the literature. Safety and efficacy of the procedures with regard to stability seem to be equivalent in initial studies but indirect measures of efficacy, such as demarcation line depth and laboratory measurements, do not always confirm equivalence of accelerated protocols in comparison to conventional one. Modified accelerated protocols must be developed in order to overcome this. Summary Accelerated CXL protocols seem to be a valid alternative to the conventional protocol; however, more comparative long term studies are needed to confirm the validity and to elucidate which accelerated protocol is ideal in each case.

Thin-flap laser in situ keratomileusis with femtosecond-laser technology

Purpose To evaluate the results of thin‐flap laser in situ keratomileusis (LASIK) using a femtosecond‐laser platform for flap creation. Setting Institute of Vision and Optics, Faculty of Medicine, University of Crete, Heraklion, Greece. Design Prospective interventional case series. Methods Patients had LASIK with the FS200 femtosecond laser for flap creation and the Allegretto Wave Eye‐Q excimer laser. Flap thickness was set at 105 &mgr;m. All eyes were examined 1 month postoperatively. Flap thickness was assessed with anterior segment optical coherence tomography using the manual flap tool at 5 locations on a horizontal B scan. Results This study comprised 50 eyes of 25 patients (mean age 28 years ±5.72 [SD]); 42 eyes completed 6 months of follow‐up. Preoperatively, the mean sphere was −3.61 ± 1.87 diopters (D) and the mean cylinder, −1.08 ± 1.23 D. Six months postoperatively, no eye lost lines of corrected distance visual acuity (CDVA), 29% gained 1 line, and 7% gained 2 lines. The mean spherical equivalent was −0.03 ± 0.42 D (range −0.88 to +0.88 D); 86% had an uncorrected distance visual acuity of 20/20 or better. The mean central flap thickness at 1 month was 102.98 ± 6.33 &mgr;m (range 91 to 114 &mgr;m). There were no intraoperative or postoperative complications. Conclusions No significant complications occurred after treatment with this new femtosecond‐laser platform in thin‐flap LASIK. Clinical (visual and refractive) results were satisfactory in terms of safety, predictability, and stability. Financial Disclosure Dr. Henderson is a consultant to Alcon Laboratories, Inc., and Baush & Lomb, Inc. No other author has a financial or proprietary interest in any material or method mentioned.

Long-term visual outcomes after Crystalens ® HD intraocular lens implantation

Purpose Our purpose was to evaluate the long-term visual outcomes after bilateral implantation of Crystalens® HD (Bausch and Lomb, Inc.) accommodative intraocular lenses. Methods In this study, 25 patients (50 eyes) who underwent cataract surgery and bilateral Crystalens HD accommodative intraocular lens implantation were included. The Crystalens HD lens was implanted in the bag in both eyes, without any intra- or postoperative complications. The visual parameters measured before and after surgery were: uncorrected distance visual acuity, corrected distance visual acuity (CDVA) (using the Early Diabetic Retinopathy Study [EDTRS] logMAR charts), uncorrected intermediate visual acuity, and uncorrected near visual acuity using a Birkhäuser reading chart, at a distance of 66 cm and 33 cm for intermediate and near vision, respectively, directly illuminated by a lamp of 60 watts. After surgery, the patients were evaluated at 1, 3, 6, 12, 24, and 36 months. Results The mean age was 68.70±7.1 (range: 54 to 83) years. The mean follow-up was 42.72±0.49 (range: 42.33 to 43.27) months. The uncorrected distance visual acuity improved from 0.56±0.41 (range: 0 to 2) preoperatively to 0.19±0.13 (range: 0 to 0.38) (logMAR scale) at the last follow-up visit, and the CDVA improved from 0.17±0.18 (range: 0 to 0.7) preoperatively to 0.05±0.05 (range: −0.02 to 0.22) at the last follow-up visit. No eyes lost lines of CDVA during the follow-up period, while 54% of patients gained one or more lines of CDVA. The uncorrected intermediate and near visual acuity was J2 or better in 71% and 69% of our patients, respectively. Conclusion Crystalens HD implantation seems to provide an improvement in visual acuity for far, intermediate, and near distances.

Ocular biomarkers in diseases and toxicities

Research is ongoing in the field of identification of molecular biomarkers concerning ophthalmology. Such molecules may be helpful in early detection of a disease, predicting the severity of a disease and the rate of disease progression, and also monitoring response to treatment. In this chapter we focus on molecular biomarkers that are involved in the diagnosis and management of several ocular pathologies, as well as in ocular toxicity deriving from agents prescribed for other systemic conditions. Such toxicity may be observed in variable forms deriving from several agents. The fields of ocular disease that have been most studied for identification of biomarkers are ocular surface disease, keratoconus, glaucoma, ocular malignancies, and retinal disease. Several molecules have been identified regarding all these entities. Other than identification, quantification of biomarkers under standardized conditions is the target in order to achieve clinical utility.

Nepafenac Ophthalmic Suspension 0.3% for the Management of Ocular Pain After Photorefractive Keratectomy

PURPOSE To investigate the effect of nepafenac 0.3% in a once daily dosage regarding pain and healing after photorefractive keratectomy (PRK). METHODS This was a prospective, comparative, contralateral randomized study of 35 patients undergoing PRK for the correction of low to moderate myopia and myopic astigmatism. After randomization, patients received nepafenac 0.3% ophthalmic suspension once daily in one eye (nepafenac 0.3% group) and nepafenac 0.1% ophthalmic suspension three times a day in the other eye (nepafenac 0.1% group) until the second postoperative day. Pain was evaluated every 2 hours on the day of the operation and then once daily using a scale ranging from 0 to 4. Patients were then examined at 2 weeks and 1, 3, 6, and 12 postoperative months. Visual acuity and subepithelial haze were also assessed. RESULTS No differences were detected between groups in pain scores, subepithelial haze scores, or visual acuity. Refractive predictability was also similar. CONCLUSIONS Nepafenac 0.3% ophthalmic suspension in a daily regimen after PRK seems to be an effective treatment for pain and ocular discomfort with effects similar to the 0.1% suspension. [J Refract Surg. 2018;34(3):171-176.].