Corneal flattening following collagen crosslinking for keratoconus: Findings at 5-year follow-up.

PURPOSE: To study the corneal flattening effect of cross-linking (CXL) overtime and to look for a potential association with preoperative topographic variables and the central depth of demarcation line (DDL). METHODS: 201 eyes of 146 patients (mean age of 31.2 ± 7.3 years) with progressive keratoconus who underwent CXL between June 2007 and December 2012 were enrolled in this retrospective study. Follow-up visits were performed at different time intervals for at least 5 years. Preoperative parameters and depth of demarcation line were collected from LaserVision ophthalmology center in Lebanon. Corneal flattening was defined by a change in postoperative Kmax (ΔKmax) greater than 1.00 D. RESULTS: ΔKmax increased from 50.25% to 61.69%, from first to last follow-up visits. The only factor significantly correlated to ΔKmax during all follow-up visits was preoperative maximum keratometry (Kmax) especially when greater than 50.00 D (OR, 1.92; 95% CI, 1.10-3.34). All eyes showed a corneal demarcation line (mean central depth (DDL): 217.11 ± 26.54 µm), with no statistically significant correlation between DDL and ΔKmax. CONCLUSION: CXL effect on cornea can be cumulative overtime and delayed flattening occurs in some cases. ΔKmax is positively correlated with preoperative Kmax and no association was found between ΔKmax and DDL. Therefore, DDL may not be a valid measure for the efficacy of CXL.

CENTRAL SEROUS CHORIORETINOPATHY ASSOCIATED WITH STEROID ENEMA.

BACKGROUND/PURPOSE: To report a case of acute recurrent central serous chorioretinopathy that developed after a regimen of corticosteroid enemas and suppositories. METHODS: Observational case report. Fluorescein angiography and spectral domain optical coherence tomography. RESULTS: A 47-year-old male patient with ulcerative colitis managed through hydrocortisone enemas presented to clinic with a 1-day history of blurry vision of his left eye. Posterior segment examination revealed subretinal fluid in the superotemporal macula of the left eye extending centrally. After diagnosis of acute central serous chorioretinopathy, the patient was advised to taper steroid enemas and his visual symptoms and subretinal fluid resolved within the month. Seven years later, several months after using steroid suppositories for the first time since the original central serous chorioretinopathy episode, asymptomatic subretinal fluid accumulation with foveal sparing was found on routine ophthalmic examination. Three months later, most of this fluid had resolved with minimal residual subretinal fluid on clinical examination. CONCLUSION: Acute central serous chorioretinopathy may develop after corticosteroid enema or suppository use, a route of administration that has not been previously reported in association with the disease.

Management of cataract in keratoconus: early visual outcomes of different treatment modalities.

A review of 31 eyes with keratoconus who developed cataract and underwent phacoemulsification. Visual acuities were measured 1mo postoperatively. Six eyes with a history of good corrected distance visual acuity (CDVA) and a similar refractive and topographic astigmatic axis were implanted with toric intraocular lenses (IOLs). The mean postoperative uncorrected distance visual acuity (UDVA) was 0.2 logMAR with a spherical equivalent (SE): 0.75D. Eleven eyes with a history of good CDVA and different refractive and topographic axis were implanted with monofocal IOL+/-Toric implantable collamer lenses to treat anisometropia and ametropia; mean UDVA was 0.25 logMAR with a mean SE: -0.51 D postoperatively. Six eyes with poor CDVA were first treated with intra-corneal ring segments, followed by phacoemulsification, the mean postoperative UDVA was 0.82 logMAR with an SE: 0.22 D. Eight eyes had advanced ectesia and received combined phacoemulsification and penetrating keratoplasty. Our approach is efficient in addressing ametropia after cataract surgery in keratoconic eyes.

Effect of phase-plate adjustment on retinal image sharpness and visible retinal area on ultrawide field imaging.

BACKGROUND: To evaluate changes in image sharpness across ultrawide field (UWF) images and the effect of phase-plate adjustment on image contrast and extent of visible retinal area (VRA). METHODS: This was a single site evaluation of 200° UWF images acquired with phase-plate adjustment (California, Optos, plc) and without (200TX, Optos, plc). Images were acquired using standardized protocol. VRA was manually outlined on each image and quantified using customized software. Mean image sharpness was evaluated using an automated method within the full VRA of each image and within the peripheral region of the VRA. The VRA and image sharpness were evaluated and compared between the two devices. RESULTS: Twenty eyes of 10 healthy volunteers were evaluated. Devices with and without phase-plate adjustment produced a similar extent of VRA. Eye steering increased VRA in devices with and without phase-plate adjustment by 39.3% and 34.3%, respectively. Regardless of gaze direction, mean sharpness of the full VRA was reduced in peripheral area with or without phase-plate adjustment. Compared to images without phase-plate adjustment, use of phase-plate adjustment reduced the loss of peripheral image sharpness in all fields (-4.2 to -26.0%; p < 0.001 all fields). The sharpness of the peripheral area for on-axis images was 61.5% higher with phase-plate adjustment. CONCLUSIONS: The use of phase-plate adjustment does not alter the extent of VRA. However, for on-axis images the loss of sharpness in the periphery is 4.5-fold less with phase-plate adjustment, potentially reducing the need to steer images and improving lesion detection in these areas.

Inducing fibrogenesis and new interfibrillary bonds in post-laser in situ keratomileusis keratectasia.

Flap creation weakens the cornea and is a risk factor for keratectasia after laser in situ keratomileusis (LASIK). We describe a new technique to halt the progression of keratectasia by mechanically reintegrating the flap into the residual stroma. Deep stromal vertical puncturing is performed in the 4.0 to 9.0 mm paracentral corneal zone at a depth of 350 to 420 µm. The puncturing is applied in circumferential rows using a 25-gauge needle or a diamond blade, with denser puncturing at the level of the cone. In 5 eyes with worsening post-LASIK keratectasia, improved uncorrected and corrected visual acuities, corneal flattening, and a hyperopic shift were observed. There was no progression of keratectasia on serial topographies. New collagen fibrogenesis was documented by optical coherence tomography. The technique seems to be promising to halt the progression of post-LASIK keratectasia. More clinical data and longer follow-up are needed for validation.

EFFICACY OF INTRAVITREAL RANIBIZUMAB INJECTIONS IN THE TREATMENT OF VITREOUS HEMORRHAGE RELATED TO PROLIFERATIVE DIABETIC RETINOPATHY.

PURPOSE: To investigate the efficacy of intravitreal ranibizumab injections in proliferative diabetic retinopathy associated with vitreous hemorrhage (VH). METHODS: A prospective study including patients with proliferative diabetic retinopathy who presented with persistent VH. Vitreous hemorrhage was graded into mild, moderate, and severe. Patients were randomized into two groups: the ranibizumab group was treated with intravitreal injections of ranibizumab and the control group was assigned to observation alone. Vitrectomy was performed if there was any aggravation of the VH in patients with mild, moderate, and severe VH or in the absence of improvement by 16 weeks in patients with moderate and severe VH. RESULTS: The ranibizumab group included 71 patients and the control group included 62 patients. There was a statistically significant difference in the vitrectomy rate in patients with mild-to-moderate VH (5 patients [7.04%] and 12 patients [19.35%], respectively; P = 0.04). However, there was no statistically significant difference in the overall vitrectomy rate, and in the vitrectomy rate in severe VH (17 [23.94%] and 12 [16.90%] patients in the ranibizumab group vs. 22 [35.48%] and 10 [16.13%] patients in the control group, P = 0.14 and P = 0.83, respectively). Recurrence of the VH occurred in 22 patients in the ranibizumab group and 29 patients in the control group (P = 0.06). Better visual acuity measurements were recorded on all follow-up visits in the ranibizumab group (P ≤ 0.04). CONCLUSION: Intravitreal ranibizumab injections could be considered in proliferative diabetic retinopathy patients with mild and moderate VH.

Mathematical analysis of corneal remodelling after intracorneal ring surgery in keratoconus.

AIM: To represent mathematically the intersection between the ectatic corneal geometry and the plane of intracorneal ring implants (ICRS) in order to determine the corneal response to ICRS surgery in keratoconus (KC). Thereafter, to present the concept and early results of a newly derived topography-guided nomogram for ICRS surgery for the treatment of keratectasia. METHODS: The corneal rings plane intersection was modelled to a conic section. Ring effect was the result of: the ring size, position (steep vs flat), location (distance from the geometric centre of the cornea), and the discrepancy between the ring's curvature and the tunnel's curvature. Femtosecond laser was used to create the tunnels and the incision sites were chosen according to the nomogram in order to place the thickest ring in the steepest portion of the cornea regardless of the astigmatism axis of refraction. RESULTS: The conic section had a more prolate shape in the steep area of the cornea than in the flat area, depending on the corneal sagittal curvature. Equal ring size had more flattening effect in the steep area than in the flat area. Thick segment should be implanted under the steep portion of the cornea regardless of the cylinder axis of refraction. Single segment in the steep area was sufficient in early and moderate cases of KC. The new nomogram provided more topographic regularity with significant reduction of astigmatism and better improvement in uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA) than the conventional nomogram. CONCLUSION: The newly derived nomogram can produce better results than the conventional nomogram. Moreover, based on this concept, a new nomogram can be integrated into the femtosecond laser software to create topography-guided, customized, elliptical tunnels with modified focal asphericity that allows for customized focal flattening of the irregularly steepened ectatic cornea.

Hemorrhage and/or Microaneurysm Severity and Count in Ultrawide Field Images and Early Treatment Diabetic Retinopathy Study Photography.

OBJECTIVE: To evaluate detection of hemorrhage and/or microaneurysm (H/Ma) using ultrawide field (UWF) retinal imaging as compared with standard Early Treatment Diabetic Retinopathy Study (ETDRS) 7-field photographs (ETDRS photos). DESIGN: Single-site comparative study of UWF images and ETDRS photos. PARTICIPANTS: One hundred twenty-six eyes of 69 patients with no diabetic retinopathy (DR) or mild or moderate nonproliferative DR (NPDR). METHODS: Stereoscopic 200° UWF images and stereoscopic 35mm 30° 7-field color photographs were acquired on the same visit. Images were graded for severity and distribution of H/Ma. H/Mas were counted in ETDRS fields 2 to 7 in both ETDRS photos and UWF images. H/Mas in the UWF peripheral fields were also counted. MAIN OUTCOME MEASURES: Kappa (κ) and weighted κ statistics for agreement. Number of H/Ma within and outside ETDRS fields identified in UWF images and ETDRS photos. RESULTS: Distribution of DR severity by ETDRS photos was 24 (19.0%) no DR, 48 (38.1%) mild NPDR, and 54 (42.9%) moderate NPDR. A total of 748 of 756 fields (98.9%) were gradable for H/Mas on ETDRS photos and UWF images. Simple κ/weighted κ statistics for severity of H/Ma: all fields 0.61/0.69, field 2 0.70/0.77, field 3 0.62/0.73, field 4 0.50/0.62, field 5 0.54/0.65, field 6 0.64/0.70, and field 7 0.58/0.63 with overall exact agreement in 81.3% and within 1 step in 97.9% of fields. A greater proportion of fields was graded a more severe H/Ma level in UWF images than in the corresponding ETDRS photos (UWF: 12.7% vs. ETDRS: 6.5%). Evaluating comparable areas in UWF images and ETDRS photos (fields 2-7), a mean of 42.8 H/Mas were identified using ETDRS photos and 48.8 in UWF images (P = 0.10). An additional mean of 21.3 H/Mas (49.8% increase, P < 0.0001) were identified in the peripheral fields of the UWF images. CONCLUSIONS: There is good to excellent agreement between UWF images and ETDRS photos in determining H/Ma severity, with excellent correlation of H/Ma counts within ETDRS photo fields. UWF peripheral fields identified 49.8% more H/Ma, suggesting a more severe H/Ma in 12.7% of eyes. Given the additional lesions detected in peripheral fields and the known risks associated with H/Ma and peripheral lesions, quantification of H/Ma using UWF images may provide a more accurate representation of DR disease activity and potential greater accuracy in predicting DR progression.

Evidence-Based Treatment of Diabetic Macular Edema.

Diabetes mellitus is a chronic disease that affects 415 million people worldwide. Despite treatment advances, diabetic eye disease remains a leading cause of vision loss worldwide. Diabetic macular edema (DME) is a common cause of vision loss in diabetic patients. The pathophysiology is complex and involves multiple pathways that ultimately lead to central retinal thickening and, if untreated, visual loss. First-line treatment of DME has evolved from focal/grid laser established by the Early Treatment of Diabetic Retinopathy Study (ETDRS) to intravitreous pharmacologic therapy. Landmark prospective clinical trials examining the effect of intravitreous injections of vascular endothelial growth factor (VEGF) inhibitors in the treatment of DME have demonstrated improved visual outcomes over focal grid laser. This review focuses on the scientific evidence treatment of DME, disease pathophysiology, clinical disease course, current treatment standards, and emerging novel therapeutic approaches.

Evidence-Based Treatment of Diabetic Retinopathy.

Diabetic retinopathy (DR) is the most frequent microvascular complication from diabetes and requires annual screening and at least annual follow-up. A systemic approach to optimize blood glucose and blood pressure may halt progression to severe stages of DR and obviate the need for ocular treatment. Although there is evidence of benefit from fenofibrate or intravitreous antiVEGF treatment for eyes with nonproliferative DR (NPDR), these therapies are not standard care for NPDR at this time. Some patients with severe NPDR, especially those with type 2 diabetes, benefit from early panretinal photocoagulation (PRP). Once DR progresses to proliferative DR (PDR), treatment is often necessary to prevent visual loss. PRP remains mainstay treatment for PDR with high-risk characteristics. However, intravitreous antiVEGF injections appear to be a safe and effective treatment alternative for PDR through at least two years. Vitreoretinal surgery is indicated for PDR cases with non-clearing vitreous hemorrhage and/or tractional retinal detachment.

An Update on the Safety and Efficacy of Corneal Collagen Cross-Linking in Pediatric Keratoconus.

Keratoconus is a degenerative disease that affects adolescents and young adults and presents with variable thinning and conical deformation of the corneal apex. The resultant irregular astigmatism can progress to levels that can significantly affect everyday activities and overall quality of life. Therefore, stopping the progression of the disease is an essential part in managing patients with keratoconus. Corneal collagen cross-linking is a minimally invasive procedure that stiffens the anterior corneal stroma by creating strong covalent bonds between collagen fibrils. Over the past decade, many studies have proved its safety and efficacy in halting keratoconus progression in adults. This review of the literature highlights the growing trend towards using this treatment in pediatric keratoconic patients. In children, keratoconus tends to be more severe and fast progression is often encountered requiring closer follow-up intervals. Standard cross-linking shows comparable results in children with a good safety-efficacy profile during follow-up periods of up to three years. Further research is needed to standardize and evaluate transepithelial and accelerated cross-linking protocols as these could be of tremendous help in a population where cooperation and compliance are major issues.

Extensive superior limbic keratoconjunctivitis in Graves' disease: case report and mini-review of the literature.

BACKGROUND: Superior limbic keratoconjunctivitis (SLK) is characterized as an inflammation of the superior bulbar conjunctiva with predominant involvement of the superior limbus and adjacent epithelial keratitis. METHODS: A 51-year-old woman, with a history of medically controlled Graves' disease was seen with an extensive SLK involving 5 mm of the superior cornea. RESULTS: Total remission was observed with topical steroids (DXM). Recurrence was observed 1 week after steroid discontinuation, and steroidal treatment was reintroduced with tapering over 1 month. Total remission was then observed for 1 year. CONCLUSION: Extensive keratitis and vascular pannus in SLK is rarely reported. This form could be treated with topical steroids. Tapering treatment remains essential for long-term success.

Safety and visual outcome of Visian toric ICL implantation after corneal collagen cross-linking in keratoconus.

PURPOSE: To evaluate the safety and clinical outcome of phakic Visian toric implantable collamer lens (ICL) (STAAR Surgical, Monrovia, CA) insertion after corneal collagen cross-linking (CXL) in progressive keratoconus. METHODS: A retrospective study examined the results of the two-step CXL and Visian toric ICL implantation in 16 eyes of 10 patients with keratoconus. The two procedures were done at an interval of 6 months. Data were collected preoperatively, at the 6-month follow-up visit after CXL, and at the 6-month follow-up visit after ICL implantation. RESULTS: CXL induced a statistically significant decrease in steep keratometry (50.02 ± 4.07 at baseline to 48.74 ± 4.05 at 6 months after CXL, P = .001) without any significant change in visual acuity or refraction. At 6-month follow-up after ICL implantation, mean K (max) was 50.49 ± 4.07 versus 52.29 ± 4.79 D at baseline (P = .001). Mean uncorrected distance visual acuity improved from 1.67 ± 0.49 to 0.17 ± 0.06 logMAR (P = .001) and mean corrected distance visual acuity improved from 0.15 ± 0.06 to 0.12 ± 0.04 logMAR (P = .023). Mean spherical equivalent decreased from -7.24 ± 3.53 to -0.89 ± 0.76 D (P = .001) and mean cylinder decreased from 2.64 ± 1.28 to 1.16 ± 0.64 D (P = .001). The safety and efficacy indices were 1.08 ± 0.13 and 0.97 ± 0.08, respectively. No intraoperative or postoperative complications occurred. CONCLUSIONS: Implantation of the Visian toric ICL following CXL is an effective option for improving visual acuity in patients with keratoconus.

Comparison of 2 types of intrastromal corneal ring segments for keratoconus.

PURPOSE: To assess the effectiveness and safety of 2 types of 6.0 mm intrastromal corneal ring segments (ICRS) in patients with mild to severe keratoconus. SETTING: Lebanese American University, Beirut, Lebanon. DESIGN: Retrospective comparative case series. METHODS: Eyes had implantation of Intacs SK ICRS (Group 1) or Keraring SI6 ICRS (Group 2). Visual acuity (logMAR), refraction, keratometry, and higher-order aberrations were compared 6 months and 1 year postoperatively. RESULTS: Group 1 comprised 66 eyes and Group 2, 107 eyes. The groups were comparable preoperatively. One-year postoperatively, the mean uncorrected distance visual acuity improved by 0.62 logMAR ± 0.19 (SD) in Group 1 and by 0.67 ± 0.17 logMAR in Group 2 (P=.211). The mean corrected distance visual acuity improved by 0.12 ± 0.11 logMAR and by 0.08 ± 0.13, respectively (P=.301). The spherical equivalent decreased by a mean of 2.80 ± 2.87 D and 2.65 ± 3.00 D, respectively (P=.572). Keratometry (K) flat and K steep decreased by a mean of 1.51 ± 1.57 D and 2.24 ± 1.61 D, respectively, in Group 1 and by 1.10 ± 2.00 D and 1.44 ± 1.64 D, respectively, in Group 2 (P=.667 and P=.184, respectively). Primary coma root mean square decreased by a mean of 1.09 ± 0.66 µm in Group 1 and 0.99 ± 0.72 µm in Group 2 (P=.716). CONCLUSION: Both ICRS models significantly improved visual function in patients with keratoconus, with comparable postoperative profiles and no major complications. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Patient-perceived pain during laser in situ keratomileusis: comparison of fellow eyes.

PURPOSE: To compare pain scores during laser in situ keratomileusis (LASIK) between first-eye surgery and second-eye surgery. SETTING: Private practice, Beirut, Lebanon. DESIGN: Cohort study. METHODS: Sequential bilateral LASIK was performed between January 2010 and January 2011 by the same surgeon using a Schwind Amaris excimer laser. Hemodynamics and intraocular pressure (IOP) were monitored intraoperatively. Patients graded their pain perception on a 4-point scale after the completion of each eye's surgery. RESULTS: The study enrolled 154 patients. The first surgery was performed in the right eye in 106 patients and in the left eye in 48 patients. Patients reported discomfort during suction (mean pain score 0.80 ± 0.56 [SD]). More pain was reported during second-eye surgery by 74% of patients; 2% reported more pain in the first eye, and 24% reported equal pain in both eyes. The mean pain score was 0.63 ± 0.35 in the first eye and 0.93 ± 0.51 in the second eye (P=.01). Pain was higher during second-eye surgery whether the procedure was started in the right eye or in the left eye. Systolic blood pressure was also higher during second-eye surgery (P=.001). There was no statistically significant difference in diastolic blood pressure, heart rate, IOP, or suction-ring pressure. CONCLUSIONS: Patients had more pain during second-eye LASIK for reasons that are not clear. A psychological explanation or regional sensitization processes are potential factors and should be studied. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Transepithelial photorefractive keratectomy: clinical results.

PURPOSE: To assess the effectiveness, safety, and comfort of transepithelial photorefractive keratectomy (PRK) using the Amaris laser platform. SETTING: Ophthalmic Consultants of Beirut, Jal-El-Dib, Metn, Lebanon. DESIGN: Comparative case series. METHODS: Myopic eyes with or without astigmatism were treated by transepithelial PRK (study group) and compared with variable-adjusted eyes treated by conventional PRK (control group) during which the epithelium was removed with alcohol. Postoperative pain, epithelial healing time, uncorrected distance visual acuity (UDVA), manifest refraction, and haze were analyzed. RESULTS: The mean subjective postoperative pain score (out of 10, indicating worst pain) at 48 hours was 2.0 in the study group (50 eyes) and 4.5 in the control group (50 eyes) (P=.02). The mean time to complete epithelial healing was 2.5 days ± 0.6 (SD) and 3.7 ± 0.8 days, respectively (P=.01). At 1 week, the UDVA was statistically significantly better in the control group; however, at 3 months, there was no statistically significant difference in UDVA, corrected distance visual acuity, or manifest refraction between the groups. Haze was significantly less in the study group (P<.01). CONCLUSIONS: Transepithelial PRK for mild to moderate myopia with or without astigmatism was safe and easier to perform than conventional PRK, and patients had less pain, less postoperative haze, and a faster healing time. The visual outcomes with the 2 techniques were comparable. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.