Intraocular lens power calculation after excimer laser corneal refractive surgery: A retrospective study to compare the predictability and the efficacy of commonly used and modified formulas.

PURPOSE: Our article aims to assess the accuracy of modified and commonly used formulas of intraocular lens (IOL) power calculation after excimer laser corneal refractive surgery. METHODS: This is a retrospective study, with data retrieved for 50 eyes of 32 patients who underwent uncomplicated cataract surgery after excimer laser corneal refractive surgery. The expected spherical equivalent was calculated using the American Society of Cataract and Refractive Surgeons (ASCRS) IOL power calculator for Shammas and Barrett True-K, using three-fourth generation formulas (Haigis-L, Barrett True-K no history, and Holladay 2), and using three-third generation formulas (SRKT, Holladay 1, and Hoffer Q) with single k, as a reference, and adjusting these formulas by calculating the keratometry readings by two methods (Jarade's index and formula). The mean refractive error and mean absolute refractive error (MARE) were calculated at the 1 postoperative month. RESULTS: When all data was available (eight eyes), 13 formulas were compared. Holladay 1 as modified by Jarade's index and formula, and Hoffer Q as modified by Jarade's formula resulted in MARE <0.75D (P < 0.05). In the group of 25 eyes with only ablation available, the formulas with MARE <0.75D were Haigis L, Barrett TK (from ASCRS), Hoffer Q, and the three conventional formulas in Jarade's index (P < 0.001). In the group of 17 eyes with no available prerefractive data, only Haigis-L and Barret TK (no history) had a MARE <0.75 D. CONCLUSION: The use of Hoffer Q or Holladay 1, when prerefractive data are available, gives reliable results with Jarade's index.

Next Generation Sequencing Identifies Five Novel Mutations in Lebanese Patients with Bardet-Biedl and Usher Syndromes.

AIM: To identify disease-causing mutations in four Lebanese families: three families with Bardet-Biedl and one family with Usher syndrome (BBS and USH respectively), using next generation sequencing (NGS). METHODS: We applied targeted NGS in two families and whole exome sequencing (WES) in two other families. Pathogenicity of candidate mutations was evaluated according to frequency, conservation, in silico prediction tools, segregation with disease, and compatibility with inheritance pattern. The presence of pathogenic variants was confirmed via Sanger sequencing followed by segregation analysis. RESULTS: Most likely disease-causing mutations were identified in all included patients. In BBS patients, we found (M1): c.2258A > T, p. (Glu753Val) in BBS9, (M2): c.68T > C; p. (Leu23Pro) in ARL6, (M3): c.265_266delTT; p. (Leu89Valfs*11) and (M4): c.880T > G; p. (Tyr294Asp) in BBS12. A previously known variant (M5): c.551A > G; p. (Asp184Ser) was also detected in BBS5. In the USH patient, we found (M6): c.188A > C, p. (Tyr63Ser) in CLRN1. M2, M3, M4, and M6 were novel. All of the candidate mutations were shown to be likely disease-causing through our bioinformatic analysis. They also segregated with the corresponding phenotype in available family members. CONCLUSION: This study expanded the mutational spectrum and showed the genetic diversity of BBS and USH. It also spotlighted the efficiency of NGS techniques in revealing mutations underlying clinically and genetically heterogeneous disorders.

Acute Angle-closure Glaucoma as a First Presentation of Coats' Disease: A Case Report.

PURPOSE: The purpose of this study was to report an unusual first manifestation of Coats' disease presenting as an acute angle-closure glaucoma attack in an adult patient. PATIENTS AND METHODS: A 37-year-old African woman presented to the emergency department with severe headache, ocular pain, and no light perception in the left eye. The left pupil was middilated and nonreactive, and the intraocular pressure (IOP) by applanation tonometry was 47 mm Hg. Slit-lamp examination revealed anterior subcapsular opacification (glaukomflecken), posterior synechiae, and total angle closure with iris bombé. A fundus examination revealed macular exudation, inferior vascular dilation, and tortuosity with peripheral telangiectasia and macroaneurysms, in addition to partial exudative retinal detachment involving the macula. On the basis of these findings, Coats' disease was diagnosed. RESULTS: The patient was treated with antiglaucoma medications and laser peripheral iridotomy to control the IOP, which had decreased to 21 mm Hg the following day. Diode laser transscleral cyclophotocoagulation was performed to further decrease the IOP. After completing a 360 degree laser, the IOP decreased to 8 mm Hg and then stabilized around 12 mm Hg. The vision remained no light perception; however, the patient felt major symptomatic relief. CONCLUSIONS: The present case describes acute angle-closure glaucoma as an initial presentation of Coats' disease in adults. Clinicians should be aware that this unique presentation in Coats' disease can occur even without retinal detachment.

Central island formation after cataract surgery in a laser in situ keratomileusis eye: New etiology.

We report a case of central corneal steepness formation after cataract surgery in a post-laser in situ keratomileusis (LASIK) eye. A 51-year-old woman with traumatic cataract and a history of myopic LASIK surgery had uneventful phacoemulsification cataract surgery. Postoperatively, the corneal topography difference map showed a central island formation of 2.1 diopters (D) compared with the preoperative level, which correlated with a clinical myopic shift of 2.00 D from the targeted emmetropia. At 4 months, most of the central island had resolved spontaneously. At 15 months, topography returned to preoperative levels. We speculate that wound hydration in the flap interface during surgery resulted in a pond-like fluid accumulation in the center of the cornea, resulting in a myopic refractive shift. We report this case because of the high probability that this phenomenon could be confounded by an erroneous intraocular lens (IOL) calculation and the potential for a serious iatrogenic complication from a premature IOL exchange or touch-up procedure.

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.

Non-topography-guided PRK combined with CXL for the correction of refractive errors in patients with early stage keratoconus.

PURPOSE: To evaluate the safety and clinical outcome of combined non-topography-guided photorefractive keratectomy (PRK) and corneal collagen cross-linking (CXL) for the treatment of mild refractive errors in patients with early stage keratoconus. METHODS: A retrospective, nonrandomized study of patients with early stage keratoconus (stage 1 or 2) who underwent simultaneous non-topography-guided PRK and CXL. All patients had at least 2 years of follow-up. Data were collected preoperatively and postoperatively at the 6-month, 1-year, and 2-year follow-up visit after combined non-topography-guided PRK and CXL. RESULTS: Seventy-nine patients (140 eyes) were included in the study. Combined non-topography-guided PRK and CXL induced a significant improvement in both visual acuity and refraction. Uncorrected distance visual acuity significantly improved from 0.39 ± 0.22 logMAR before combined non-topography-guided PRK and CXL to 0.12 ± 0.14 logMAR at the last follow-up visit (P <.001) and corrected distance visual acuity remained stable (0.035 ± 0.062 logMAR preoperatively vs 0.036 ± 0.058 logMAR postoperatively, P =.79). The mean spherical equivalent decreased from -1.78 ± 1.43 to -0.42 ± 0.60 diopters (D) (P <.001), and the mean cylinder decreased from 1.47 ± 1.10 to 0.83 ± 0.55 D (P <.001). At the last follow-up visit mean keratometry flat was 43.30 ± 1.75 vs 45.62 ± 1.72 D preoperatively (P = .03) and mean keratometry steep was 44.39 ± 3.14 vs 46.53 ± 2.13 D preoperatively (P = .02). Mean central corneal thickness decreased from 501.74 ± 13.11 to 475.93 ± 12.25 µm following combined non-topography-guided PRK and CXL (P < .001). No intraoperative complications occurred. Four eyes developed mild haze that responded well to a short course of topical steroids. No eye developed infectious keratitis. CONCLUSIONS: Combined non-topography-guided PRK and CXL is an effective and safe option for correcting mild refractive error and improving visual acuity in patients with early stable keratoconus.

An implantable intraocular pressure transducer: initial safety outcomes.

IMPORTANCE: To our knowledge, this is a report of the first implantation of a wireless intraocular pressure transducer (WIT) in a human eye. OBJECTIVE: To report preliminary safety data on the WIT. DESIGN, SETTING, AND PARTICIPANT: In an institutional setting, a patient with open-angle glaucoma consented to be the recipient of the WIT in one eye in an interventional study design. INTERVENTIONS: The WIT was implanted into the ciliary sulcus following extracapsular cataract extraction and "in the bag" intraocular lens implantation. The patient was monitored postoperatively for 18 months. MAIN OUTCOMES AND MEASURES: Any adverse events. RESULTS: There were no complications noted during the WIT insertion or postoperatively. No persistent intraocular inflammation, pigment dispersion, or angle narrowing was noted. CONCLUSIONS AND RELEVANCE: The WIT was well tolerated in the eye and no overt signs of toxicity or other adverse events were noted. This may allow the constant monitoring of intraocular pressure in the future.

Non-topography-guided photorefractive keratectomy for the correction of residual mild refractive errors after ICRS implantation and CXL in keratoconus.

PURPOSE: To evaluate the safety and clinical outcomes of non-topography-guided photorefractive keratectomy (PRK) for the treatment of residual mild refractive errors 6 months after sequential intracorneal ring segment (ICRS) implantation and corneal collagen cross-linking (CXL) in stable keratoconus. METHODS: This retrospective study included 17 eyes of 14 patients with mild to moderate keratoconus. The ICRS implantation and CXL were performed sequentially with a 4-week interval and non-topography-guided PRK was performed at least 6 months after CXL. Data were collected preoperatively and at the 6-month follow-up visits. RESULTS: ICRS implantation and CXL induced a significant decrease in keratometry and refraction and an increase in visual acuity. At the 6-month follow-up after ICRS implantation and CXL, uncorrected and corrected distance visual acuity (UDVA and CDVA) significantly improved from 1.17 ± 0.38 and 0.44 ± 0.09 logMAR preoperatively to 0.45 ± 0.11 and 0.17 ± 0.08 logMAR (P = .001) postoperatively, respectively. The mean spherical error decreased from -5.45 ± 1.64 to -2.57 ± 1.15 D (P = .01) and the mean cylinder from 3.86 ± 1.15 to 2.13 ± 1.11 D (P = .01). At the 6-month follow-up after PRK, UDVA significantly improved to 0.18 ± 0.06 logMAR and CDVA was 0.15 ± 0.05 logMAR. The mean spherical error and mean cylinder significantly decreased to -1.10 ± 0.41 D (P = .02) and 0.98 ± 0.37 D (P = .046), respectively. No intraoperative or postoperative complications occurred. CONCLUSIONS: At the 6-month follow-up, non-topography-guided PRK after ICRS implantation and CXL was found to be an effective and safe option for correcting residual refractive error and improving visual acuity in patients with moderate keratoconus.

Gamma-irradiated corneas as carriers for the Boston type 1 keratoprosthesis: advantages and outcomes in a surgical mission setting.

PURPOSE: The Boston keratoprosthesis (KPro) is the most commonly used KPro worldwide. There are limited data on the outcomes when irradiated corneas are used as KPro carriers. We report a retrospective analysis of corneal transplantations performed in a regular surgical mission setting in Beirut, Lebanon, using the Boston KPro type 1 and gamma-irradiated carrier corneas, and we describe visual outcomes, complications, and retention percentage. METHODS: We conducted a retrospective analysis of 17 consecutive eyes from 16 patients who underwent Boston KPro type 1 implantation at the Beirut Eye Specialist Hospital between December 2010 and July 2012. Patient medical records were reviewed for preoperative, intraoperative, and postoperative details. RESULTS: Postoperatively, 9 (52.9%), 5 (29.4%), and 2 (11.7%) eyes had a corrected visual acuity of 20/400 or better, 20/100 or better, and 20/40 or better, respectively, at the most recent follow-up visit. A total of 16 eyes (94.1%) improved in corrected visual acuity over the course of follow-up. Overall, 13 eyes (76.4%) developed at least 1 complication after surgery. Retroprosthetic membrane formation was the most common complication, occurring in 10 eyes (58.8%). Neither infectious keratitis nor corneal stromal necrosis was noted during the follow-up period. The retention percentage was 94.1%. CONCLUSIONS: The visual acuity outcomes, incidence of complications, and retention percentage of the KPro using gamma-irradiated carrier corneas are comparable with the outcomes of KPro implantation reported in the literature using fresh grafts as carriers. KPro with irradiated corneal carrier grafts seems to be an effective option to increase the supply of transplantation suitable corneas in remote areas, where fresh corneal grafts may be scarce.

Visian toric ICL implantation after intracorneal ring segments implantation and corneal collagen crosslinking in keratoconus.

PURPOSE: To evaluate the safety and clinical outcome of Visian toric implantable collamer lens (TICL) implantation for the treatment of residual refractive errors 6 months after sequential intracorneal ring segments (ICRS) and corneal collagen UVA crosslinking (CXL) in stable keratoconus. METHODS: This retrospective study examined the results of a 3-step ICRS-CXL-TICL in 11 eyes of 7 patients with moderate to severe keratoconus. The 2 procedures (ICRS-CXL) were performed sequentially at an interval of 4 weeks and TICL implantation was performed at least 6 months after CXL. Data were collected preoperatively, at the 6-month follow-up visit after sequential ICRS-CXL, and at the 6-month follow-up visit after TICL implantation. RESULTS: The ICRS-CXL induced a significant decrease in keratometry, increase in visual acuity, and decrease in refraction. At 6-month follow-up after ICRS-CXL, mean Kflat was 45.19 ± 3.98 D vs 48.51 ± 4.26 D preoperatively (p = 0.022) and mean Ksteep was 50.41 ± 4.32 D vs 54.24 ± 4.96 D preoperatively (p = 0.032). Uncorrected distance visual acuity (UCVA) significantly improved from 1.47 ± 0.38 logMAR before ICRS-CXL to 0.27 ± 0.20 logMAR 6 months after (p = 0.002). Corrected distance visual acuity (CDVA) significantly improved from 0.50 ± 0.22 logMAR to 0.29 ± 0.23 logMAR (p = 0.001). At 6 months post TICL implantation, UCVA improved significantly to 0.27 ± 0.20 logMAR and the CDVA was 0.19 ± 0.11 logMAR. No intraoperative or postoperative complications occurred. CONCLUSIONS: Toric ICL implantation after sequential ICRS implantation and CXL is an effective and safe option for correcting high residual refractive error and improving visual acuity in patients with moderate to severe keratoconus.

Bilateral macular injury from a green laser pointer.

We report the case of a 13-year-old boy who had a bilateral macular injury after playing with a green laser pointer for a duration of 1 minute. Clinical examination revealed a decrease in visual acuity and macular injury in both eyes, and imaging investigations revealed a bilateral macular lesion due to exposure to the laser pointer. At 3 months' follow up, visual function had improved but remained partially impaired. This case emphasizes the importance of cautious and appropriate use of laser pointer devices because of the potential vision-threatening hazards induced by mishandling of these devices.