Corneal Irregularity Induced by Transepithelial Photorefractive Keratectomy in a Patient With Partial Limbal Stem Cell Deficiency

PURPOSE

The aim of this study was to present a case of transepithelial photorefractive keratectomy (trans-PRK) laser ablation in a patient with partial limbal stem cell deficiency (LSCD) that resulted in corneal irregularity.

METHODS

A 23-year-old man with bilateral partial LSCD underwent trans-PRK for myopia correction 2 months before presentation to our department. Trans-PRK ablation was performed with a phototherapeutic keratectomy ablation profile set at 60 μm in the OD and 57 μm in the OS and 8 mm zone. At the time of presentation, the patient complained of decreased visual acuity. Corrected distant visual acuity was 20/20 (-3.25, -0.75 × 180 degrees) and 20/50 (-3.00, -3.00 × 180 degrees) in the OD and the OS, respectively. No further ocular history was reported other than prolonged soft contact lens use for myopia. Pre-trans-PRK tomography (WaveLight Oculyzer II diagnostic system, WaveLight GmbH, Germany) revealed bilateral superior steepening with corresponding epithelial thinning as obtained by the epithelial map using Optovue optical coherence tomography (Visionix Luneau technology). Slit-lamp examination showed bilateral superficial neovascularization, suggestive of early-stage LSCD.

RESULTS

A nonuniform laser stromal ablation resulting in corneal irregularity and decreased visual acuity was observed 2 months postoperatively. During the 6-month follow-up, corneal tomography was stable with only minimal improvement. At that time, corrected distant visual acuity remained 20/20 (-2.75, -0.75 × 160 degrees) in the OD and 20/50 (-3.00, -3.00 × 180 degrees) in the OS.

CONCLUSIONS

Trans-PRK seems to be a contraindication in cases with corneal epithelial irregularities and could lead to abnormal and nonuniform stromal ablation .

Three-Year Results of Simultaneous Transepithelial Phototherapeutic Keratectomy and Conventional Photorefractive Keratectomy (Cretan Protocol Plus) Followed by Corneal Crosslinking for Keratoconus

PURPOSE

The aim of this study was to present the 3-year outcomes after simultaneous transepithelial phototherapeutic keratectomy (t-PTK) and conventional photorefractive keratectomy (PRK) followed by corneal crosslinking (CXL) for keratoconus.

METHODS

In this prospective, interventional case series, patients with progressive keratoconus underwent simultaneous t-PTK and conventional PRK followed by CXL (Cretan protocol plus). Visual, refractive, and topographic outcomes were evaluated along with endothelial cell density (ECD) preoperatively and at 1, 2, and 3 years postoperatively.

RESULTS

Twenty-two patients (31 eyes) were enrolled. No intraoperative or postoperative complications were observed in any of the patients. Logarithm of the minimum angle of resolution (logMAR) mean uncorrected and mean corrected distance visual acuity improved from 0.81 ± 0.40 and 0.18 ± 0.21 preoperatively to 0.38 ± 0.33 ( P < 0.001) and 0.06 ± 0.12 ( P < 0.001) at 3-year follow-up. Mean spherical equivalent improved from -5.39 ± 3.89 diopters (D) preoperatively to -2.29 ± 2.65 D ( P < 0.001) at 3 years postoperatively. Mean corneal astigmatism reduced from -4.70 ± 2.86 D preoperatively to -3.55 ± 2.45 D ( P = 0.001) at 3 years postoperatively. No ECD alterations were observed throughout the 3-year follow-up ( P > 0.05).

CONCLUSIONS

Simultaneous t-PTK and conventional PRK followed by CXL seems to be an effective and safe treatment for progressive keratoconus over 3-year follow-up.

Combined Astigmatic Arcuate Keratotomy with Descemet Automated Endothelial Keratoplasty

We report the results of simultaneous astigmatic arcuate keratotomy (AK) and Descemet automated endothelial keratoplasty (DSAEK). A 55-year-old patient with a history of high myopia was referred for the management of bullous keratopathy secondary to an anterior chamber phakic intraocular lens (pIOL). IOL explantation through a 5.5-mm corneal incision, cataract extraction, and posterior chamber IOL implantation, combined with DSAEK, were performed. Postoperatively, increased astigmatism up to 2.0 diopters (Dpt) was observed, attributed to the large corneal incision, and remained stable, despite suture removal at 3 months. One year postoperatively, the graft showed signs of progressive endothelial dysfunction. A combined procedure of astigmatic AK and DSAEK was thus performed. After 6 months, topographic astigmatism was significantly reduced to 0.5 Dpt and best-corrected visual acuity increased. In conclusion, simultaneous astigmatic AK and DSAEK could be an effective combination for treating patients with well-documented pre-existing astigmatism and endothelial decompensation.

Intraocular Lens Refractive Index and Its Impact on External Surface Reflections

PURPOSE

To determine and compare the origin of the external surface reflections produced by commonly used intraocular lenses (IOLs).

METHODS

The specular reflection taking place at the anterior surface of eight types of IOLs (IOL power = 22.00 diopters [D]) with different refractive indices (RIs), optical design, and ultraviolet and blue light-filtering function were measured. The experimental set-up included a laser beam light source (3.5 mW, 532 nm) and a saline-filled model eye containing the IOL to be examined. External surface reflections were measured using a power meter, and the IOL surface reflectance (%) was compared among the eight IOLs investigated.

RESULTS

External reflections from the anterior surface of the studied implants increased as the RI of the IOL material increased. The IOL models composed of high RI material (RI = 1.56 ± 0.02) were found to have a more than threefold higher external surface reflections compared to those with low RI (RI = 1.45 ± 0.02). Ultraviolet or blue light-filtering functions showed no significant correlation with the external reflectance.

CONCLUSIONS

IOLs with a high RI are associated with external surface reflections that are more than threefold higher than those with lower RI. The "cat's eye" phenomenon seen in pseudophakic eyes by an outside observer strongly depends on the RI, but is independent of the filter incorporated in the IOL. [J Refract Surg. 2021;37(6):398-402.].

Small incision lenticule extraction retreatment in a patient with high residual refractive error after photorefractive keratectomy: A case report

A 36-year-old male underwent uneventful small incision lenticule extraction (SMILE) for the correction of his high residual refractive error 12 years after photorefractive keratectomy (PRK). Preoperatively, uncorrected distance visual acuity (UDVA) was counting fingers in both eyes. Corrected distance visual acuity was 20/20 in the right and 20/30 in the left eye due to amblyopia. One month after SMILE, UDVA was 20/20 and 20/30 in the right and left eye, respectively; post-PRK corneal haze had reduced. During the 4-year follow-up, UDVA remained stable and there were no complications. SMILE could be a good alternative approach for retreatment in post-PRK patient.

Corneal cross-linking (CXL) combined with refractive surgery for the comprehensive management of keratoconus: CXL plus

The past two decades have witnessed an unprecedented evolution in the management of keratoconus that demands a holistic approach comprising of inhibiting the ectatic progression as well as visual rehabilitation. The advent of corneal cross-linking (CXL) in the late 1990s resulted in long-term stabilization of the ectatic cornea along with limited reduction in corneal steepening and regularization of corneal curvature. However, CXL as a standalone procedure does not suffice in rehabilitating the functional vision especially in patients who are unwilling or intolerant towards contact lenses. The concept of “CXL plus” was proposed which incorporates adjunctive use of refractive procedures with CXL in order to overcome the optical inefficiency due to corneal irregularity, decrease the irregular astigmatism, correct the residual refractive error and improve functional visual outcome in keratoconus. Several refractive procedures such as conductive keratoplasty (CK), photorefractive keratectomy (PRK), transepithelial phototherapeutic keratectomy (t-PTK), intrastromal corneal ring segments (ICRS) implantation, phakic intraocular lens (PIOL) implantation and multiple other techniques have been combined with CXL to optimize and enhance the CXL outcome. This review aimed to summarize the different protocols of CXL plus, provide guidelines for selection of the optimum CXL plus technique and aid in decision-making for the comprehensive management of cases with primary keratoconus in addition to discussing the future and scope for innovations in the existing treatment protocols.

Evolution of corneal flattening after repeated corneal cross-linking during a 6-year follow-up

PURPOSE

To report the evolution of corneal flattening after repeated corneal cross-linking (CXL) in a patient with progressive keratoconus during a 6-year follow-up.

METHODS

Case report.

RESULTS

A 27-year-old female underwent CXL for progressive keratoconus. Postoperatively, corneal topography revealed keratoconus progression with an increase of 1.20 diopters (D) in maximum keratometry (Kmax) and CXL was repeated. After the second treatment, a continuing significant corneal flattening (up to 16.00 D in Kmax) was observed during the first 5 years followed by stabilization during the last sixth year of follow-up. Both uncorrected and corrected distance visual acuity were improved while corneal thickness was decreased. There were no complications such as corneal opacification or endothelial cells decrease during the follow-up period.

CONCLUSION

Repeated CXL can induce an excessive corneal flattening more pronounced during the first years of follow-up followed by stabilization thereafter.

Accuracy of dynamic contour tonometry, Goldmann applanation tonometry, and Tono-Pen XL in edematous corneas

Purpose:

To investigate in vitro the accuracy of dynamic contour tonometry, Goldmann applanation tonometry, and Tono-Pen XL in edematous corneas.

Methods:

Experimental study included 20 freshly enucleated porcine eyes. Epithelium was debrided, and eyes were divided in four groups. Groups were immersed in 35%, 40%, 50%, and 60% glycerin solutions for 3 hours. Subsequently, globes were mounted in a special holder, and their intraocular pressure was hydrostatically adjusted. Intraocular pressure was measured by means of dynamic contour tonometry, Goldmann applanation tonometry, and Tono-Pen XL while adjusting true intraocular pressure to 17, 33, and 50 mm Hg. Ultrasound pachymetry was performed.

Results:

Mean corneal thickness was 914.5 ± 33.3 μm (730–1015 μm). In true intraocular pressure of 33 mm Hg, Goldmann applanation tonometry and dynamic contour tonometry significantly underestimated true intraocular pressure (mean Goldmann applanation tonometry: 14.7 ± 4.8 mm Hg, p < 0.001, mean dynamic contour tonometry: 21.6 ± 6.8, p < 0.001). Tono-Pen XL also underestimated, but difference was not statistically significant (Tono-Pen XL: 27.9 ± 9.7, p = 0.064). In true intraocular pressure of 50 mm Hg, all three methods significantly underestimated (Goldmann applanation tonometry: 17.6 ± 5.3 mm Hg, p < 0.001, dynamic contour tonometry: 26.8 ± 6.3 mm Hg, p < 0.001, Tono-Pen XL: 35.6 ± 8.4 mm Hg, p < 0.001). The error in measured intraocular pressure for each method (true minus measured intraocular pressure) was significantly correlated to true intraocular pressure (p < 0.001). The intraocular pressure measurements of each eye taken under true intraocular pressure of 17 and 33 mm Hg with the three methods were correlated to each other. Measurements taken under intraocular pressure of 50 mmHg were not correlated to each other. Corneal thickness was not correlated to intraocular pressure measurement.

Conclusion:

Goldmann applanation tonometry, dynamic contour tonometry, and Tono-Pen XL underestimate intraocular pressure when measured under edematous conditions. Tono-Pen XL showed better accuracy, especially in lower true intraocular pressure. The measurement error increases when true intraocular pressure increases in all three methods.

Combined DSAEK and intraocular lens flipping with retropupillary fixation in a patient with anterior chamber iris-claw intraocular lens and corneal edema

An 84-year-old monocular woman was referred to our institution for the management of corneal decompensation in her only eye, the right eye. The patient had secondary implantation of an anterior chamber iris-claw intraocular lens (IOL) for IOL dislocation in the setting of pseudoexfoliation syndrome 2 years before presentation. Descemet-stripping automated endothelial keratoplasty (DSAEK) combined with retropupillary repositioning of the iris-claw IOL using a flipping technique was performed for the treatment of corneal edema. No intraoperative or postoperative complications occurred. Six months postoperatively, the corneal graft was attached and clear and the retropupillary iris-claw IOL was well positioned. The uncorrected distance visual acuity and corrected distance visual acuity improved from counting fingers preoperatively to 20/200 and 20/63, respectively, after surgery. Combined DSAEK and retropupillary refixation of a prepupillary iris-claw IOL using the flipping technique was a safe technique in this patient with corneal decompensation.

Long-term Comparison of Combined t-PTK and CXL (Cretan Protocol) Versus CXL With Mechanical Epithelial Debridement for Keratoconus

PURPOSE

To compare the long-term outcomes of corneal cross-linking (CXL) for the treatment of keratoconus using two different techniques for epithelial removal: transepithelial phototherapeutic keratectomy (t-PTK) and mechanical epithelial debridement.

METHODS

In this prospective, comparative, interventional case series, 26 patients (30 eyes) with progressive keratoconus underwent CXL treatment. Fifteen eyes (13 patients) underwent epithelial removal with t-PTK (Cretan protocol) and 15 eyes (13 patients) underwent mechanical epithelial debridement (Dresden protocol) during CXL. Visual, refractive, and keratometric outcomes were evaluated preoperatively and at 1, 2, 3, and 4 years postoperatively.

RESULTS

No intraoperative or postoperative complications were observed in any of the patients. In the Cretan protocol group, mean uncorrected (UDVA) and corrected (CDVA) visual acuity improved from 0.99 ± 0.42 and 0.33 ± 0.28 logMAR preoperatively to 0.75 ± 0.32 (P = .018) and 0.21 ± 0.16 (P = .024) logMAR at 4 years postoperatively, respectively. In the Dresden protocol group, mean UDVA improved from 0.83 ± 0.47 logMAR preoperatively to 0.63 ± 0.40 logMAR (P = .033) at 4 years postoperatively, whereas mean CDVA did not demonstrate a statistically significant improvement postoperatively (P > .05). In the Cretan protocol group, mean corneal astigmatism improved from -6.19 ± 4.54 diopters (D) preoperatively to -4.68 ± 3.10 D (P = .041) at last follow-up, whereas in the Dresden protocol group there was no statistically significant difference postoperatively (P > .05).

CONCLUSIONS

Epithelial removal with t-PTK during CXL (Cretan protocol) resulted in better visual, refractive, and keratometric outcomes compared with mechanical epithelial debridement over a long-term follow-up. [J Refract Surg. 2019;35(10):650-655.].

Combined transepithelial phototherapeutic keratectomy and conventional photorefractive keratectomy followed simultaneously by corneal crosslinking for keratoconus: Cretan protocol plus

PURPOSE

To evaluate the visual, refractive, and topographic outcomes after combined transepithelial phototherapeutic keratectomy (PTK) and conventional photorefractive keratectomy (PRK) followed simultaneously by corneal crosslinking (CXL) for keratoconus.

SETTING

Vardinoyiannion Eye Institute of Crete, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece.

DESIGN

Prospective case series.

METHODS

Patients with progressive keratoconus had simultaneous conventional PRK followed by CXL; the corneal epithelium was removed using transepithelial PTK (Cretan protocol plus). The visual, refractive, and topographic outcomes and the endothelial cell density (ECD) were evaluated preoperatively and 1, 3, 6, and 12 months postoperatively.

RESULTS

Forty-three patients (55 eyes) were enrolled. The mean uncorrected and corrected distance visual acuities improved significantly from 0.98 ± 0.63 (SD) logarithm of minimum angle of resolution (logMAR) and 0.20 ± 0.23 logMAR preoperatively to 0.39 ± 0.35 logMAR (P < .001) and 0.08 ± 0.16 logMAR (P < .001) 12 months postoperatively, respectively. The mean spherical equivalent improved significantly from -4.67 ± 4.00 diopters (D) preoperatively to -2.24 ± 2.81 D (P < .001) at 12 months. The mean steep keratometry (K) and flat keratometry readings decreased significantly from 50.30 ± 5.00 D and 45.62 ± 3.10 D preoperatively to 46.27 ± 3.90 D (P < .001) and 43.46 ± 3.00 D (P < .001) 12 months postoperatively, respectively. No ECD alterations were observed throughout the follow-up (P > .05).

CONCLUSION

Combined transepithelial PTK and conventional PRK followed simultaneously by CXL was effective in corneal stabilization and vision improvement in keratoconic patients.

Predictors of Visual Acuity Improvement and Supernormal Vision After Refined Single-Step Transepithelial Photorefractive Keratectomy

PURPOSE

To investigate predicting factors of visual acuity improvement and achieving uncorrected (UDVA) or corrected (CDVA) distance visual acuity supernormal vision (⩾ 15/10; Snellen 20/13) 1 year after refined transepithelial photorefractive keratectomy (TransPRK).

METHODS

In this retrospective case series, a total of 155 eyes with myopia (mean ± standard deviation = -3.53 ± 1.81 diopters) with and without astigmatism (range = 0.25 to 4.50 diopters) were recruited and observed for 1 year. Patients underwent refined single-step TransPRK using the SCHWIND AMARIS 500 laser (SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany). The main predicting factors of postoperative supernormal vision and visual acuity improvements were sought by statistical modeling.

RESULTS

Logistic models showed mesopic contrast sensitivity, high laser fluence, and coma higher-order aberration (HOA) as predicting factors for both UDVA and CDVA super-normal vision. Myopia, astigmatism, dynamic cyclotorsion correction, optical zone, and transitional zone showed associations only in simple models and were not retained in multivariable models. According to the linear regression models, CDVA, mesopic contrast sensitivity, coma HOA, and keratometry were common predictors of both postoperative UDVA and CDVA improvement compared to preoperative UDVA. Astigmatism, optical and transitional zones, and high laser fluence were common predictors only in simple regression models.

CONCLUSIONS

Through statistical modeling, preoperative CDVA, mesopic contrast sensitivity, coma HOA, and simulated keratometry were found to be the main factors that predicted improvement of both postoperative CDVA and UDVA compared to preoperative CDVA. Furthermore, mesopic contrast sensitivity, coma HOA, and high laser fluence were the common predictors of achieving both CDVA and UDVA supernormal vision 1 year after refined single-step TransPRK. [J Refract Surg. 2019;35(12):771-780.].

Use of Radiofrequency Diathermy for the Treatment of Chronic Corneal Neovascularization with Lipid Keratopathy

Purpose:

To present the use of radiofrequency diathermy for the management of chronic resistant corneal neovascularization with lipid keratopathy.

Methods:

Two post keratitis patients with chronic corneal neovascularization and lipid keratopathy refractory to conventional treatment underwent radiofrequency diathermy. (Klöti, Oertli ®, Switzerland) on an outpatient basis under topical anesthesia at the slit lamp biomicroscope.

Results:

No intra- or postoperative complications were encountered. After the procedure, significant regression of neovascularization with decrease in lipid deposition and improvement in corneal opacification was observed in both patients during the 12-month follow-up. Corrected distance visual acuity improved from 20/200 preoperatively to 20/80 postoperatively in the first case while remained stable at 20/20 in the second case. Significant symptomatic improvement regarding photophobia and discomfort was noted in both patients.

Conclusions:

Radiofrequency diathermy seems to represent an effective and safe minimally invasive treatment for chronic resistant corneal neovascularization with lipid keratopathy.

Occult Spontaneous Ocular Perforation Presenting as Conjunctival Chemosis in a Patient with Marfan's Syndrome

We report a case of occult spontaneous ocular perforation presenting as conjunctival chemosis in a patient with Marfan's syndrome (MFS). A 38-year-old female with MFS presented with bilateral conjunctival chemosis since 6 months. Best-corrected visual acuity was 20/20 in both eyes. On slit-lamp examination, a diffuse conjunctival chemosis was observed in both eyes without any signs of ocular hypotony (decreased visual acuity, low intraocular pressure, shallow anterior chamber, pupil distortion, hypotony maculopathy, and chorioretinal folds). Anterior-segment optical coherence tomography revealed a corneoscleral fistula at the left nasal limbus, without any similar finding in the right eye. A scleral patch was performed at the site of the perforation. At 3 month's follow-up, the left chemosis had regressed, with a stable best-corrected visual acuity in both eyes. However, on ultrasound biomicroscopy, another fistula at the right superior limbus was found, and the patient was referred for treatment with a scleral patch. In conclusion, conjunctival chemosis in a patient with MFS should raise the suspicion of an occult spontaneous ocular perforation.

Intraoperative Photoactivated Chromophore for Infectious Keratitis-Corneal Cross-Linking (PACK-CXL) During Penetrating Keratoplasty for the Management of Fungal Keratitis in an Immunocompromised Patient

INTRODUCTION

To present a novel intraoperative application of photoactivated chromophore for infectious keratitis-corneal cross-linking (PACK-CXL) in the management of post-penetrating keratoplasty (PKP) multiresistant fungal keratitis in a patient with irradiation-related local immunosuppression.

CASE REPORT

A 62-year-old female underwent uneventful PKP for the management of post-irradiation actinic keratopathy. Three months postoperatively, she presented with a diffuse corneal melting abscess that was infiltrating the donor-recipient junction. Despite intensive antibiotic and antifungal therapy, corneal melting progressed to graft perforation. A repeat PKP combined with intraoperative PACK-CXL was performed. PACK-CXL was applied initially on the infected graft, involving the corneoscleral rim and then following placement of the donor button. No intra- or postoperative graft-related complications were encountered. No signs of infection were noted, and the graft remained clear during the 9-month follow-up period.

CONCLUSION

Intraoperative PACK-CXL combined with PKP appears to be a safe and effective technique for the management of post-PKP resistant fungal keratitis.

Combined Pupilloplasty and Retropupillary Iris-Claw Intraocular Lens Implantation with DSAEK in a Patient with Traumatic Iridoplegia, Aphakia and Corneal Decompensation

Purpose

To report the management of a patient with traumatic mydriasis, aphakia and corneal decompensation with a triple procedure: simultaneous pupilloplasty and retropupillary iris-claw intraocular lens (IOL) implantation combined with Descemet stripping automated endothelial keratoplasty (DSAEK).

Results

An 88-year-old woman was referred to our Institute for consultation on her left eye. The patient had undergone surgical removal of the IOL, without re-implantation, in her left eye 10 months prior to presentation due to traumatic IOL dislocation. At the time of examination, corrected distance visual acuity was counting fingers and intraocular pressure was 10 mmHg. Slit-lamp examination revealed iridoplegia, aphakia and corneal edema. The patient underwent simultaneous pupilloplasty and retropupillary iris-claw IOL implantation combined with DSAEK. Six months postoperatively, the corneal graft was attached and clear, the iris was well reconstructed and almost round, and the iris-claw IOL was in place.

Conclusions

Simultaneous pupilloplasty and retropupillary iris-claw IOL implantation combined with DSAEK was shown to be a safe surgical technique in a patient with traumatic mydriasis, aphakia and corneal decompensation.

Resolution of epithelial ingrowth after combined photorefractive keratectomy and corneal crosslinking in a patient with post-LASIK ectasia

A 34-year-old man was referred to our institute for evaluation of the left eye because of corneal ectasia 10 years after bilateral laser in situ keratomileusis (LASIK). Three months before his referral, the patient had a flap lift for the management of interface fluid accumulation. Topography demonstrated post-LASIK corneal ectasia and slitlamp evaluation revealed epithelial ingrowth in the stromal interface inferiorly. The patient underwent uneventful combined photorefractive keratectomy (PRK) and corneal crosslinking (CXL) to stabilize the corneal ectasia and improve his functional vision. One month after the treatment, slitlamp evaluation revealed complete resolution of stromal interface epithelial ingrowth. At 12 months postoperatively, significant visual and topographic improvement was noted without any evidence of epithelial ingrowth recurrence or corneal ectasia progression. Combined PRK-CXL seemed to not only treat the corneal pathology of this patient successfully, resulting in visual and topographic improvement, but it also resolved the stromal interface epithelial ingrowth.

Current concepts in crosslinking thin corneas

Corneal cross-linking (CXL), introduced by Wollensak et al. in 2003, is a minimally invasive procedure to halt the progression of keratoconus. Conventional CXL is recommended in eyes with corneal thickness of at least 400 microns after de-epithelialization to prevent endothelial toxicity. However, most of the keratoconic corneas requiring CXL may not fulfill this preoperative inclusion criterion. Moderate-to-advanced cases are often found to have a pachymetry less than this threshold. There are various modifications to the conventional method to circumvent this issue of CXL thin corneas while avoiding the possible complications. This review is an update on the modifications of conventional CXL for thin corneas.

Factors Associated With Ocular Cyclotorsion Detected by High-Speed Dual-Detection Eye Tracker During Single-Step Transepithelial Photorefractive Keratectomy

PURPOSE

To determine demographic, surgical, and preoperative visual factors affecting the level of static and dynamic cyclotorsion (SC and DC) in eyes undergoing single-step transepithelial photorefractive keratectomy (TransPRK).

METHODS

In this cross-sectional study, 386 patients with different types of refractive errors scheduled for single-step TransPRK were enrolled. A comprehensive profile of personal, optic, and visual characteristics of patients as surgical parameters were collected. Statistical modeling was used to explore correlates of SC and DC before and during the refractive procedure, respectively.

RESULTS

There was no difference in various indices of SC and DC between right and left eyes. Lower age (beta = -0.20), uncorrected (beta = -0.99) and corrected (beta = -0.72) visual acuities, and keratometry (beta = -0.09) were significantly associated with higher ranges of DC during the laser ablation procedure. Worse mesopic contrast sensitivity (beta = 0.24) and higher (beta = 0.002, left eyes) or lower (beta = -0.002, right eyes) kappa locus also showed significant associations with a higher range of DC. In cases of SC before the procedure, amount (beta = 0.46) and axis (beta = -0.003) of the astigmatism demonstrated notable associations.

CONCLUSIONS

Through comprehensive modeling, age, visual axis indices, visual acuity, and contrast sensitivity were found to be the main factors significantly associated with dynamic ocular globe cyclotorsions during single-step TransPRK. This could help identify eyes at higher risk of cyclotorsion and its potential complications in refractive surgery. [J Refract Surg. 2018;34(11):736-744.].

Comparison of Single-Step Transepithelial Photorefractive Keratectomy With or Without Mitomycin C in Mild to Moderate Myopia

PURPOSE

To compare efficacy and safety of single-step transepithelial photorefractive keratectomy (PRK) with or without mitomycin C (MMC) in patients with mild to moderate myopia.

METHODS

Patients with mild to moderate myopia (≤ -5.50 diopters [D]) underwent single-step transepithelial PRK using the Amaris laser (SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany). Total ablation depth (epithelium and stroma) was 160 μm or less. The right eye of each patient was treated with 0.02% MMC for 10 seconds, whereas the left eye did not receive any MMC. Corneal haze, endothelial cell indices, refraction, visual acuity, contrast sensitivity, and higher order aberrations were assessed preoperatively and postoperatively.

RESULTS

In this comparative case series, 71 patients (16 men and 55 women; 142 eyes) were enrolled. Mean patient age was 27.97 ± 5.74 years. Mean preoperative spherical equivalent of patients' right and left eyes were -3.20 ± 1.20 and -3.30 ± 1.20 diopters, respectively (P = .70); other preoperative visual parameters were also comparable. Incidence of 2+ grade of haze was detected in 1 (2.5%) right and 2 (5.0%) left eyes (P > .99) 3 to 6 months postoperatively. Incidence of 1+ degree of haze was also comparable. No eye developed 3+ degrees or more of haze. One year postoperatively, both eyes achieved comparable refraction, visual acuity, contrast sensitivity, and higher order aberrations, and no greater than trace haze was detected. MMC-treated eyes suffered a greater loss of endothelial cell density (P < .001) and showed higher variance in cell size (P = .001).

CONCLUSIONS

Single-step transepithelial PRK with or without MMC showed similar efficacy and incidence of haze in eyes with mild to moderate myopia with total ablation depths of 160 μm or less. However, MMC-treated eyes showed a worse profile of endothelial cell indices. Applications of MMC in this subgroup of patients may be reconsidered. [J Refract Surg. 2018;34(6):400-407.].

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.].

Uneventful Anterior Migration of Intravitreal Ozurdex Implant in a Patient with Iris-Sutured Intraocular Lens and Descemet Stripping Automated Endothelial Keratoplasty

Purpose

We report here the case of a patient with anterior segment migration of intravitreal dexamethasone implant as well as its management and outcome.

Methods

The patient had the following sequence of events: complicated cataract surgery, iris-sutured intraocular lens implant, followed by cystoid macular edema treated with intravitreal Avastin, retinal vein occlusion treated with intravitreal dexamethasone implant, corneal decompensation treated with Descemet stripping automated endothelial keratoplasty (DSAEK), and finally recurrence of macular edema treated with repeated intravitreal dexamethasone implant.

Results

Dexamethasone implant had completely dissolved from the eye 12 weeks after insertion without any complication.

Conclusion

A conservative approach with regular monitoring in the situation of a quiet anterior segment without any corneal decompensation can provide enough time for the implant to dissolve without causing any complication to the involved eye, avoiding any additional surgical intervention, as presented in this case report. Despite the fact that the implant was left for natural dissolution, there were no adverse effects related to the graft or the eye.

Flap Amputation with Phototherapeutic Keratectomy (PTK) and Adjuvant Mitomycin C for Severe Post-Lasik Epithelial Ingrowth

Purpose

To report a patient with severe post–laser in situ keratomileusis (LASIK) epithelial ingrowth and keratolysis treated with flap amputation and phototherapeutic keratectomy (PTK) with adjuvant intraoperative mitomycin C (MMC).

Methods

Case report.

Results

A 55-year-old woman was referred to our department due to severe post-LASIK epithelial ingrowth with corneal melting 2 years after primary LASIK. The patient had had two previous attempts for epithelial ingrowth treatment (flap lift and epithelial ingrowth manual removal) that were unsuccessful. Slit lamp biomicroscopy and anterior segment optical coherence tomography showed extensive epithelial ingrowth and keratolysis (thinning of the LASIK flap) while the patient had photophobia and could not tolerate contact lenses. Flap amputation with subsequent PTK (in order to smooth out the corneal irregularities caused by the keratolysis and/or variations in flap thickness) and adjuvant intraoperative MMC application for 2 minutes was performed. There were no intra- or postoperative adverse events seen during the follow-up period. Six months after the procedure, uncorrected visual acuity improved to 20/40 compared with 20/50 preoperatively, while best spectacle-corrected visual acuity improved from 20/40 to 20/32. The topographic astigmatism was decreased from 3.24 diopters (D) to 1.00 D.

Conclusions

Flap amputation with PTK and adjuvant intraoperative MMC is an option for the management of severe post-LASIK epithelial ingrowth with keratolysis.

Keratoconus Treatment Algorithm

Keratoconus management has significantly changed over the last two decades. The advent of new interventions such as cornea cross-linking, intrastromal corneal ring segments, and combined treatments provide corneal clinicians a variety of treatment options for the visual rehabilitation of keratoconus patients. This review summarizes current evidence for these treatments and highlights their place in keratoconus management while new promising emerging therapies are being investigated.

Optical Biometry Derived Axial Length Measurements Following Intravitreal Anti-Vascular Endothelial Growth Factor Treatment for Macular Edema

PURPOSE

To evaluate axial length (AL) alterations in patients with macular disease over the course of intravitreal anti-vascular endothelial growth factor (anti-VEGF) treatment.

METHODS

In this prospective, comparative study, 33 patients with macular edema underwent unilaterally intravitreal anti-VEGF therapy and were followed for two months; the contralateral eyes were considered as controls. Central retinal thickness (CRT) was measured with spectral-domain optical coherence tomography and AL with an IOL-Master optical biometer.

RESULTS

CRT of the treated eyes decreased by 35.33 ± 65.59 μm (range, -222.00-67 μm), while AL increased by 0.008 ± 0.062 mm (range, -0.11-0.18 mm). CRT of the control group decreased by 9.82 ± 65.40 μm (range, -203-182 μm), and AL increased by 0.011 ± 0.129 mm (range, -0.20-0.67 mm). No significant correlation was detected between CRT and AL parameters (rhos=0.026, P=0.882).

CONCLUSIONS

Anti-VEGF administration has no significant impact on optical biometry-derived AL measurements.

Intraocular lens power overestimation in a patient with history of circling keratorraphy

We report a case of cataract extraction and intraocular lens (IOL) power overestimation in a patient with history of hyperopia managed with circling keratorraphy. A 65-year-old female presented to our institute complaining of decreased vision in both eyes. The patient had a history of bilateral hyperopia that was managed 20 years ago (1994) with circling keratorraphy. At presentation her uncorrected distance visual acuity (UDVA) was 20/70 and 20/60 in her right eye (OD) and left eye (OS), respectively, while her corrected distance visual acuity (CDVA) was 20/25 OD and 20/25 OS with manifest refraction of −0.50 + 1.50 × 75 OD and +0.50sph + 1.50cyl × 30 OS. Slit lamp examination revealed the presence of a circular intrastromal corneal suture (6 mm diameter) and mild (+1) nuclear sclerosis in both eyes. The patient was scheduled to undergo cataract extraction targeting plano, using a toric IOL; one month after the surgery, the manifest refraction of the operated right eye was −2.00 + 0.50 × 175, reflecting an overestimation of the intraocular lens (IOL) power for the attempted target. Cataract extraction in patients with history of circling keratorraphy for the management of hyperopia results in IOL power overestimation, consistent with that which is seen in patients with other previous hyperopic corneal refractive procedures.

Corneal Stromal Demarcation Line Depth Following Standard and a Modified High Intensity Corneal Cross-linking Protocol

PURPOSE

To compare the corneal stromal demarcation line depth using anterior segment optical coherence tomography (AS-OCT) after corneal cross-linking (CXL) using two different treatment protocols: the standard Dresden protocol (30 minutes with 3 mW/cm(2)) and a modified high intensity protocol (7 minutes with 18 mW/cm(2)), corresponding to a total surface dose of 5.4 and 7.5 J/cm(2), respectively.

METHODS

This prospective, comparative, interventional case series included 29 keratoconic patients (32 eyes). All patients underwent CXL using the same high intensity ultraviolet-A (UV-A) irradiation device (CCL-365; Peschke Meditrade GmbH, Huenenberg, Switzerland). Sixteen eyes were treated for 30 minutes with 3 mW/cm(2) according to the standard Dresden protocol, whereas 16 eyes were treated with a novel modified high intensity CXL protocol for 7 minutes with 18 mW/cm(2) of UV-A irradiation intensity. One month postoperatively, corneal stromal demarcation line depth was measured by two independent observers using AS-OCT.

RESULTS

There was no significant difference in corneal stromal demarcation line depth between observer measurements for both groups (P = .645, Dresden protocol group; P = .715, high intensity group). Mean corneal stromal demarcation line depth was 341.81 ± 47.02 µm for the Dresden protocol group and 313.37 ± 48.85 µm for the high intensity protocol group. There was no statistically significant difference (P = .104) in the corneal stromal demarcation line depth between the two groups. Mean endothelial cell density did not change significantly in either group (P = .090, Dresden protocol group; P = .103, high intensity group). No intraoperative or postoperative complications were noted.

CONCLUSIONS

Corneal stromal demarcation line depth using UV-A irradiance with 3 mW/cm(2) for 30 minutes and 18 mW/cm(2) for 7 minutes was similar. It seems that the current modified accelerated CXL protocol provided the same treatment depth as the standard Dresden protocol.

Trans advanced surface laser ablation (TransPRK) outcomes using SmartPulseTechnology

PURPOSE

To evaluate early visual rehabilitation, post-operative pain, epithelial healing and haze after transepithelial photorefractive keratectomy (TransPRK) using the SmartPulseTechnology (SPT) of Schwind Amaris (Schwind eye-tech-solutions GmbH, Kleinostheim, Germany).

METHODS

This was a retrospective comparative evaluation of a cohort of myopic patients undergoing TransPRK with SPT (group 1), with one matched control group that underwent conventional TransPRK (group 2). All cases had a 6-month post-operative follow-up including visual acuity and slit-lamp examination. Subjective evaluation of pain was recorded post-operatively.

RESULTS

49 eyes of 25 patients in group 1 and 40 eyes of 20 patients in group 2 were enrolled. The patients' visual rehabilitation was significantly faster in group 1, one day and one week post-operatively (P<0.05). From one month onward there was no significant difference between the groups. The epithelial defect size was significantly smaller on post-operative days 1 and 2 for group 1 (P<0.05 in both cases). The pain score was also significantly less in group 1 (P<0.05). The haze level had no significant difference between the groups at any post-operative point (P>0.05).

DISCUSSION

TransPRK using SPT provides promising results in the early post-operative period. Visual rehabilitation, re-epithelialization and pain were faster in the early post-operative period in group 1 in comparison with group 2. Haze formation was not significantly different between the two groups; however, it was consistently less in group 1.

Long-Term Comparison of Simultaneous Topography-Guided Photorefractive Keratectomy Followed by Corneal Cross-linking versus Corneal Cross-linking Alone

PURPOSE

To compare the results of corneal collagen cross-linking (CXL) alone with combined simultaneous topography-guided photorefractive keratectomy plus CXL (tPRK-CXL) for progressive keratoconus for a 3-year interval.

DESIGN

Prospective, comparative interventional case series.

PARTICIPANTS

Forty-eight patients (60 eyes) with progressive keratoconus.

METHODS

Thirty eyes underwent combined tPRK with a solid-state laser (maximum ablation depth, 50 μm) followed by CXL, and 30 eyes underwent CXL alone. Groups were matched in terms of age and keratoconus stage.

MAIN OUTCOME MEASURES

Corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), keratometry, and corneal confocal microscopy.

RESULTS

Mean follow up was 39±11 months. Mean age at operation was 28±5.82 years. Before surgery, average CDVA in the tPRK-CXL group was 0.26±0.17 logarithm of the minimum angle of resolution (logMAR), and in the CXL group was 0.24±0.18 logMAR (P = 0.58). At last follow-up, CDVA was 0.09±0.10 logMAR in the tPRK-CXL group and 0.15±0.12 logMAR in the CXL group (P < 0.05). In both groups, no patient lost more than 2 lines of Snellen visual acuity, whereas 19 eyes and 8 eyes in the tPRK-CXL group and in the CXL group, respectively, gained 2 or more lines of CDVA. Before surgery, average UDVA was 0.83±0.54 logMAR in the tPRK-CXL group and 0.86±0.62 logMAR in the CXL group (P = 0.79). At last follow-up, UDVA was 0.27±0.25 logMAR in the tPRK-CXL group and 0.69±0.58 logMAR in the CXL group (P < 0.001). Before surgery, steep and flat keratometry had no significant differences between groups, and at last follow-up, both steep and flat keratometry readings were significantly flatter in the tPRK-CXL group compared with the CXL group. Depth of CXL treatment, as evaluated by confocal microscopy, was 269.8±31.8 μm in the CXL group and 299.7±29.8 μm in the tPRK-CXL group (P < 0.001). No differences were found in endothelial cell density.

CONCLUSIONS

Simultaneous tPRK followed by CXL in this series of keratoconus patients offered significantly improved vision to treated patients in comparison with CXL alone, and similar results regarding postoperative stability. Safety concerns regarding corneal thickness were taken into account in treatment planning.

Intravitreal ketorolac for the treatment of chronic cystoid macular edema after cataract surgery

Purpose

To report two cases of chronic postoperative cystoid macular edema, resistant to topical therapy, treated with consecutive intravitreal injections of ketorolac tromethamine.

Methods

Four daily intravitreal injections of 500 μg/0.05 mL of ketorolac were given to each patient. Complete clinical examination and OCT were performed before every injection, 1, 2, 3 weeks, and 1, 3, and 6 months after the last injection. Fluorescein angiography was performed at baseline examination, 1, 3, and 6 months after the last injection.

Results

In both cases, the edema regressed and visual acuity increased. At 6 months after the last injection, the leakage was significantly reduced at the fluorescein angiography.

Discussion

Both cases responded favorably to the consecutive intravitreal administration of ketorolac tromethamine. The long-lasting remission of the macular edema in these chronic cases underlines the therapeutic potential of these agents when delivered intravitreally.

Mitomycin-C in corneal surface excimer laser ablation techniques: a report by the American Academy of Ophthalmology

OBJECTIVE

To review the published literature assessing the efficacy and safety of mitomycin-C (MMC) as an adjunctive treatment in corneal surface excimer laser ablation procedures.

METHODS

Literature searches of the PubMed and Cochrane Library databases were last conducted on August 19, 2014, without language or date limitations. The searches retrieved a total of 239 references. Of these, members of the Ophthalmic Technology Assessment Committee Refractive Management/Intervention Panel selected 26 articles that were considered to be of high or medium clinical relevance, and the panel methodologist rated each article according to the strength of evidence. Ten studies were rated as level I evidence, 5 studies were rated as level II evidence, and the remaining 11 studies were rated as level III evidence.

RESULTS

The majority of the articles surveyed in this report support the role of MMC as an adjunctive treatment in surface ablation procedures. When MMC is applied in the appropriate concentration and confined to the central cornea, the incidence of post-surface ablation haze is decreased. Although a minority of studies that evaluated endothelial cell density (ECD) reported an MMC-related decrease in ECD, no clinical adverse outcomes were reported.

CONCLUSIONS

Over the past 15 years, the use of MMC during surgery in surface ablation has become widespread. There is good evidence of the effectiveness of MMC when used intraoperatively as prophylaxis against haze in higher myopic ablations. Although there are reports of decreased endothelial counts after the administration of MMC during surgery, the clinical significance of this finding remains uncertain, because no adverse outcomes were reported with as much as 5 years of follow-up. Optimal dosage, effectiveness as prophylaxis in lower myopic and hyperopic ablations, and long-term safety, particularly in eyes with reduced corneal endothelial cell counts from prior intraocular surgery, have yet to be established.

Corneal Collagen Cross-Linking Mushroom Shape Demarcation Line Profile After Limited Bowman's Membrane Removal by Phototherapeutic Keratectomy

Purpose :

To report a corneal collagen cross-linking (CXL) mushroom shape demarcation line profile after limited Bowman’s membrane removal by phototherapeutic keratectomy (PTK).

Methods :

Case report.

Results :

A twenty-one-year-old male with progressive keratoconus underwent mechanical epithelial debridement (at an 8.5 mm zone) followed by PTK (at a 5.0 mm zone and in a 10 μm depth) and CXL. No intra- or early postoperative complications were found. Evaluation of the corneal stromal demarcation line depth using anterior segment optical coherence tomography revealed a mushroom shape profile.

Conclusion :

It seems that removal of the Bowman’s layer leads to greater depth of the corneal stromal demarcation line.

Safety of high-intensity corneal collagen crosslinking

PURPOSE

To evaluate the safety of a new high-intensity corneal collagen crosslinking (CXL) treatment protocol for keratoconus.

SETTING

Vardinoyiannion Eye Institute of Crete, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece.

DESIGN

Prospective interventional case series.

METHODS

Patients with progressive keratoconus had CXL using a new treatment protocol with 9 mW/cm(2) irradiance for duration of 10 minutes. The rate of reepithelialization, endothelial cell density (ECD), corrected distance visual acuity (CDVA), and steep and flat keratometry (K) values were evaluated preoperatively and 3 months postoperatively.

RESULTS

Nine patients (10 eyes) were enrolled. No intraoperative or early postoperative complications were observed in any patient. The ECD did not change significantly 3 months postoperatively (P=.169). The CDVA improved from 0.19 logMAR ± 0.20 (SD) preoperatively to 0.10 ± 0.16 logMAR 3 months postoperatively; however, the improvement did not attain significance (P=.141). No eye lost lines of CDVA. The mean steep K readings decreased significantly from 48.04 ± 2.57 diopters (D) preoperatively to 46.51 ± 2.81 D 3 months postoperatively (P=.047); the mean flat K readings did not change significantly postoperatively (P=.285).

CONCLUSIONS

Corneal collagen crosslinking at 9 mW/cm(2) irradiance for 10 minutes did not cause significant changes in ECD or intraoperative or early postoperative complications. None patient lost a line of CDVA 3 months after the procedure.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Evaluation of corneal stromal demarcation line depth following standard and a modified-accelerated collagen cross-linking protocol

PURPOSE

To compare the corneal stromal demarcation line depth using anterior segment optical coherence tomography (AS-OCT) after corneal collagen cross-linking (CXL) using 2 different treatment protocols: the standard Dresden protocol (30 minutes with 3 mW/cm(2)) and a modified-accelerated protocol (14 minutes with 9 mW/cm(2)).

DESIGN

Prospective, comparative study.

METHODS

Forty-three keratoconic patients (52 eyes) were enrolled. All patients underwent CXL using the same high-intensity ultraviolet-A (UV-A) irradiation device. Twenty-six eyes were treated for 30 minutes with 3 mW/cm(2) according to the standard Dresden protocol (Group 1), while 26 eyes were treated with a novel modified-accelerated CXL protocol for 14 minutes with 9 mW/cm(2) of UV-A irradiation intensity (Group 2). One month postoperatively, corneal stromal demarcation line depth was measured by 2 independent observers using AS-OCT.

RESULTS

Corneal stromal demarcation line depth was assessed with no significant difference between observer measurements for both groups (P = .676 for Group 1 and P = .566 for Group 2). Mean corneal stromal demarcation line depth was 337.00 ± 46.46 μm for Group 1 and 322.91 ± 48.28 μm for Group 2. There was no statistically significant difference (P = .243) in the corneal stromal demarcation line depth between the 2 groups.

CONCLUSIONS

Corneal stromal demarcation line depth using UV-A with 3 mW/cm(2) for 30 minutes and 9 mW/cm(2) for 14 minutes was similar. A modified-accelerated protocol of 14 minutes of CXL provided the same treatment depth as the classic Dresden protocol.