Effect of Topical Dexmedetomidine (0.0055%) on Intraocular Pressure in Healthy Eyes: A Randomized Controlled Trial.

AIM AND OBJECTIVE: Evaluate the short-term safety and efficacy of dexmedetomidine (0.0055%) drops on intraocular pressure (IOP) in healthy eyes. MATERIALS AND METHODS: In this randomized controlled trial, patients with normal eye exams were randomly assigned to receive, in a randomly selected eye, one drop of either balanced salt solution (BSS) or dexmedetomidine (0.0055%). Goldmann applanation tonometry was performed at baseline and then 30 minutes, 4 hours, and 24 hours after drop instillation. RESULTS: Forty-nine eyes of 49 normal volunteers were enrolled in the study, with 21 eyes (group I) receiving BSS and 28 (group II) dexmedetomidine. Both groups were comparable at baseline as far as age and IOP (p = 0.55 for both parameters). Intraocular pressure significantly decreased from baseline in group II at 30 minutes and 4 hours (p = 0.001 and 0.05, respectively). Maximum IOP decrease was obtained at 30 minutes after dexmedetomidine instillation, with a 9% decrease from baseline (mean decrease: 1.15 mm Hg). The percentage of IOP decrease was significantly higher in group II at 30 minutes compared with group I (9 vs 1.1%; p = 0.05). No side effects were recorded. CONCLUSION: In this pilot study, dexmedetomidine 0.0055% drops have shown good safety and efficacy in lowering IOP in normal healthy volunteers with no history of glaucoma. This medication has a short onset of action, with a 10% reduction of IOP occurring 30 minutes post-instillation. TRIAL REGISTRATION NUMBER: NCT03690622. HOW TO CITE THIS ARTICLE: Fakhoury H, Abdelmassih Y, El-Khoury S, et al. The Effect of Topical Dexmedetomidine (0.0055%) on Intraocular Pressure in Healthy Eyes: A Randomized Controlled Trial. J Curr Glaucoma Pract 2021;15(2):58-63.

Unilateral Malignant Glaucoma Postbilateral Implantable Collamer Lens: Effect of Miotics.

An implantable collamer lens® (ICL) V4c model (STAAR Surgical, Monrovia, CA, USA) was placed in the eye of a 31-year-old male patient with high myopia followed by the development of malignant glaucoma. After failing medical treatment for 5 days, a noncomplicated pars plana vitrectomy and anterior hyaloidectomy succeeded in breaking the aqueous misdirection. Sixteen months later, intraoperative miotics were purposefully withheld from the ICL surgery in the fellow eye and malignant glaucoma did not develop. Even though the patient's visual acuity postoperatively was 20/20, OU, a single small atrophic iris patch in the affected eye resulted in slightly more halos and glare in mesopic conditions as compared to the fellow eye. Earlier surgical intervention may have prevented iris ischemia and iridocorneal touch with its subsequent iris atrophy and resulted in an even more favorable visual outcome. Withholding intraoperative miotics during ICL surgery appeared to be beneficial in this case.

Toric ICL Implantation After Sequential Intracorneal Ring Segments Implantation and Corneal Cross-linking in Keratoconus: 2-Year Follow-up.

PURPOSE: To evaluate 6-month and 2-year safety and clinical outcomes of Visian toric Implantable Collamer Lens (toric ICL) (STAAR Surgical, Monrovia, CA) implantation for the treatment of residual refractive errors after sequential intracorneal ring segments (ICRS) insertion and cross-linking (CXL) in keratoconus. METHODS: This consecutive case series included the results of a three-step ICRS-CXL-toric ICL procedure in 16 eyes of 13 patients with moderate to severe keratoconus (stages II and III of Amsler-Krumeich classification). The ICRS and CXL procedures were performed sequentially with an interval of 4 weeks and the toric ICL implantation was performed at least 6 months after CXL. Data were collected preoperatively, at 6 months after sequential ICRS-CXL, and at 6 and 24 months following toric ICL implantation. All 16 eyes were evaluated at the 2-year follow-up. RESULTS: There was a significant decrease in keratometry (steep, flat, and maximum) and refraction (sphere and spherical equivalence, but not cylinder) and a significant increase in both uncorrected (UDVA) (from 1.06 to 0.76 logMAR, P = .004) and corrected (CDVA) (from 0.42 to 0.26 logMAR; P = .002) distance visual acuity 6 months following sequential ICRS-CXL, whereas UDVA and refraction significantly improved 6 months after ICL insertion (UDVA reached 0.33 logMAR, P = .001). At the 24-month follow-up, UDVA and keratometric readings were stable, whereas CDVA, sphere, and cylinder showed a significant improvement. CONCLUSIONS: Implantation of Visian toric ICL following sequential ICRS insertion 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 in the long term. [J Refract Surg. 2017;33(9):610-616.].

Bilateral corneal epithelial macrocysts following hyperopic laser in situ keratomileusis.

A 27-year-old woman had microkeratome-assisted laser in situ keratomileusis (LASIK) for moderate bilateral hyperopia. The preoperative ophthalmologic examination was unremarkable except for minimal lissamine green staining bilaterally on the nasal conjunctiva. On the first postoperative day, the uncorrected distance visual acuity (UDVA) was 20/20 bilaterally and the corneas were clear. Four days later, the patient presented with mild blur in both eyes. Examination showed diffuse bilateral epithelial cysts encompassing the central 6.0 to 7.0 mm of the flaps with overlying diffuse lissamine green staining. The UDVA was 20/30 bilaterally. Aggressive lubrication was administered. The epithelial cysts coalesced into larger ones over subsequent visits and began regressing over several months, along with improvement in vision. At 6 months, the cysts had completely resolved, the corneas were clear, and the UDVA was 20/20.

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.

Safety and Efficacy of Sequential Intracorneal Ring Segment Implantation and Cross-linking in Pediatric Keratoconus.

PURPOSE: To evaluate the safety and visual outcome of intracorneal ring segment (ICRS) implantation followed by cross-linking in pediatric keratoconus patients. DESIGN: Retrospective interventional case series. METHODS: This retrospective study included pediatric patients (aged ≤14 years) with keratoconus and poor corrected distance visual acuity (CDVA) that underwent ICRS implantation and cross-linking (CXL). ICRS were inserted under topical anesthesia after creating a corneal tunnel with a femtosecond laser. Cross-linking was performed 1 month subsequently. Records were reviewed and data collected preoperatively and at 6 months, 1 year, 2 years, and 4 years postoperatively. RESULTS: Twelve patients (17 eyes; 10 male, 2 female) aged 9-14 years (mean age 12.3 years) received ICRS implantation followed by CXL. Follow-up times ranged from 6 months to 4 years after surgery. At the 6-month follow-up all eyes were evaluated; at the 1-year, 2-year, and 4-year follow-up 11, 10, and 7 eyes were evaluated, respectively. At the 6-month follow-up, mean CDVA in comparison to preoperative levels improved significantly (P = .001) from 0.30 ± 0.19 logMAR to 0.12 ± 0.1 logMAR; mean uncorrected distance visual acuity (UDVA) also improved significantly from 0.90 ± 0.50 logMAR to 0.43 ± 0.31 logMAR. A significant decrease in both keratometry readings and spherical equivalent (from -4.0 to -1.56 diopters) was also noted after ICRS insertion. At the 1-year, 2-year, and 4-year follow-up refractive values remained relatively stable in comparison to the 6-month follow-up, except for a minor but significant improvement in cylinder and, at 4 years, in UDVA. All patients tolerated the surgery well and no intraoperative or postoperative complications were reported, except for 1 ring segment that had to be removed after 2 years owing to vascularization and corneal thinning. CONCLUSION: ICRS implantation is a safe and effective procedure for visual rehabilitation in children with keratoconus and poor CDVA.

Pediatric Keratoconus in a Tertiary Referral Center: Incidence, Presentation, Risk Factors, and Treatment.

PURPOSE: To report the incidence, clinical presentation, risk factors, and treatment outcome of pediatric keratoconus in a tertiary referral eye hospital in Beirut, Lebanon. METHODS: In this retrospective study, the authors evaluated all patients with keratoconus 14 years or younger newly diagnosed at the Beirut Eye Specialist Hospital, Beirut, Lebanon, between January 2010 and December 2014. The incidence of pediatric keratoconus among all pediatric patients and among patients with keratoconus of all ages was assessed. Patients with pediatric keratoconus were evaluated for keratoconus stage, initial presentation, uncorrected distance visual acuity, corrected distance visual acuity (CDVA), corneal topography, and pachymetry. Patients were classified according to different treatment regimen groups and different follow-up visits were evaluated. RESULTS: During 5 years, 16,808 patients were examined, of whom 2,972 were 14 years or younger. A total of 541 patients were diagnosed as having keratoconus; of those, 16 were 14 years or younger at the time of diagnosis. Hence, the incidence of keratoconus was 0.53% among pediatric patients and 3.78% among adult patients (> 14 years). Initial presentation was during routine checkup (1 of 16) for allergic conjunctivitis (3 of 16), reduced vision (10 of 16), and corneal hydrops (mimicking keratitis) (2 of 16). Except for 2 patients lost to follow-up, all eyes received corneal cross-linking treatment and 16 eyes received additional intracorneal ring segment implantation. CONCLUSIONS: The incidence of pediatric keratoconus indicates that increased awareness for keratoconus among children is needed, mainly in cases of family history of keratoconus, ocular allergy/pruritus, poor CDVA, corneal hydrops, and/or high astigmatism. [J Refract Surg. 2016;32(8):534-541.].

Successfully managed endophthalmitis following strabismus surgery.

Endophthalmitis following strabismus surgery is rare and has been reported to occur in from 1:3,500 to 1:185,000 cases. Severe adverse sequelae, including phthisis bulbi and enucleation, occur often despite early and aggressive treatment. This report describes 3 patients with endophthalmitis following apparently uneventful strabismus surgery by three different surgeons. Infections were aggressively treated. Two patients received intravitreal steroids; all 3 returned to their preoperative baseline visual acuity.

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.

Acute corneal hydrops mimicking infectious keratitis as initial presentation of keratoconus in a 10-year-old child.

Purpose. To report a case of acute hydrops in a 10-year-old child with advanced keratoconus. Case Presentation. A ten-year-old boy diagnosed as having right eye (RE) infectious keratitis, not responding to antimicrobial therapy, was referred to our hospital. The diagnosis of infectious keratitis was established one month prior to his presentation following an episode of acute corneal whitening, pain, and drop in visual acuity. Topical fortified antibiotics followed by topical antiviral therapy were used with no improvement. Slit lamp examination showed significant corneal protrusion with edema surrounding a rupture in Descemet's membrane in the RE. The diagnosis of acute corneal hydrops from advanced keratoconus was highly suspected and confirmed with corneal topography. Conclusion. Although a relatively rare disease at the age of 10 years, keratoconus can be rapidly progressive in the pediatric group. Keratoconus should always be considered in the differential diagnosis of progressive vision loss in this age group.

Prevalence of dissociated strabismus in children with ocular misalignment: a population-based study.

PURPOSE: The purpose of this study was to report the prevalence of dissociated strabismus among a population-based cohort of children diagnosed with all forms of ocular misalignment. METHODS: The medical records of all children (<19 years of age) identified by the resources of the Rochester Epidemiology Project who were diagnosed with strabismus while residing in Olmsted County, Minnesota, from January 1, 1985, through December 31, 1994, were retrospectively reviewed for the prevalence of dissociated vertical (DVD) or horizontal (DHD) deviations. RESULTS: Of 627 children with strabismus, 12 (1.9%) were found to have DVD at their initial diagnosis at a mean age of 52 months (range, 3.5-206 months). During a mean follow-up of 10.4 years (range, 1-20 years), an additional 44 children were diagnosed with DVD, yielding a total of 50 children (7.9%). The common strabismus subtypes with the highest prevalence of DVD were, in declining order, congenital esotropia (53%), esotropia in the setting of a developmental deficit (25%), and accommodative esotropia (3.4%). None of the subjects were recorded as having DHD. CONCLUSIONS: In this patient cohort, DVD was relatively uncommon and occurred most frequently among those with early-onset strabismus and strabismus in the setting of a developmental deficit.

Assessment of anterior and posterior corneal indices using two Scheimpflug analyzers.

PURPOSE: To assess the agreement between the elevation and curvature measurements of the anterior and posterior corneal surfaces obtained using the Galilei Dual Scheimpflug Analyzer and those obtained using the Pentacam single Scheimpflug system. METHODS: This prospective, noninterventional, diagnostic study was conducted at the Department of Ophthalmology at the American University of Beirut (Medical Center) and included 60 eyes of 60 consecutive patients. Measurements were obtained using 2 different Scheimpflug analyzers (Galilei and Pentacam). The best-fit sphere was set at 8 mm in both machines. Pachymetry (CCT), anterior elevation (AE) and posterior elevation (PE), and curvature were assessed. Pearson's correlation coefficients, comparison of means, and Bland-Altman plots were used to evaluate agreement between the 2 systems. RESULTS: The average CCT (at the corneal apex) was 533 ± 35 µm and 532 ± 37 µm (p=0.980), the average central AE was 1.25 ± 3.95 µm and 2.29 ± 5.28 µm (p=0.964), and the average central PE was 4.19 ± 8.18 µm and 5.42 ± 14.05 (p=0.956) µm with the Galilei and Pentacam, respectively. CONCLUSION: The Scheimpflug analyzers correlated well in the assessment of pachymetry, elevation, and curvature.

Assessment of anterior and posterior corneal indices using two Scheimpflug analyzers / Índices da córnea anterior e posterior com dois analisadores Scheimpflug

Purpose: To assess the agreement between the elevation and curvature measurements of the anterior and posterior corneal surfaces obtained using the Galilei Dual Scheimpflug Analyzer and those obtained using the Pentacam single Scheimpflug system. Methods: This prospective, noninterventional, diagnostic study was conducted at the Department of Ophthalmology at the American University of Beirut (Medical Center) and included 60 eyes of 60 consecutive patients. Measurements were obtained using 2 different Scheimpflug analyzers (Galilei and Pentacam). The best-fit sphere was set at 8 mm in both machines. Pachymetry (CCT), anterior elevation (AE) and posterior elevation (PE), and curvature were assessed. Pearson's correlation coefficients, comparison of means, and Bland-Altman plots were used to evaluate agreement between the 2 systems. Results: The average CCT (at the corneal apex) was 533 ± 35 µm and 532 ± 37 µm (p=0.980), the average central AE was 1.25 ± 3.95 µm and 2.29 ± 5.28 µm (p=0.964), and the average central PE was 4.19 ± 8.18 µm and 5.42 ± 14.05 (p=0.956) µm with the Galilei and Pentacam, respectively. Conclusion: The Scheimpflug analyzers correlated well in the assessment of pachymetry, elevation, and curvature. .

Objetivo: Avaliar a concordância entre as medidas de elevação e curvatura das superfícies anterior e posterior da córnea obtidos pelos analisadores de Scheimpflug Galilei e Pentacam. Método: Estudo de teste diagnóstico, prospectivo, não-intervencional realizado no Departamento de Oftalmologia do Centro Médico da Universidade Americana de Beirute. Sessenta olhos de 60 pacientes consecutivos. As medições foram feitas usando dois analisadores Scheimpflug diferentes (Galilei e Pentacam). A esfera de melhor ajuste foi fixada em 8 mm para ambos equipamentos. Paquimetria (CCT), elevação anterior (AE) e elevação posterior (PE), e curvatura foram avaliados. Coeficientes de correlação de Pearson, comparação das médias, e gráficos de Bland-Altman foram utilizados para avaliar a correlação. Resultados: A média de CCT (no ápice da córnea) foi 533 ± 35 µm usando o Galilei e 532 ± 37 µm usando o Pentacam (p=0,980). As médias centrais de AE foram de 1,25 ± 3,95 µm e 2,29 ± e 5,28 µm com o Galilei e Pentacam, respectivamente (p=0,964). As médias de centrais de PE foram 4,19 ± 8,18 µm e 5,42 ± 14,05 µm com a Galilei e Pentacam, respectivamente (p=0,956). Conclusões: Os analisadores de Scheimpflug avaliados correlacionam bem em termos de paquimetria, elevação e curvatura. .

Slipped, severed, torn and lost extraocular muscles.

Slipped, severed, torn and lost extraocular muscles (EOM) are infrequently encountered in clinical practice but constitute significant complications of strabismus and other eye surgery and of orbital injuries. Knowledge of the clinical aspects of these various disease entities and their anatomical underpinnings are of utmost importance in providing effective recognition and treatment. These conditions share some common presenting signs, symptoms and clinical findings that are discussed in this review. The literature will be reviewed and management strategies will be presented.

Unilateral proptosis in a 60-year-old man.

A 60-year-old immunocompromised patient developed rapidly progressive proptosis that was secondary to mucormycosis. This life-threatening fungal infection usually is associated with chemosis, proptosis, ophthalmoplegia, and visual loss. The fungus may invade ocular structures, sinuses, and extend into the brain. The standard of care includes correction of the underlying condition, administration of liposomal amphotericin B with posaconazole, and surgical debridement of infected and necrotic tissue. We present a case of unilateral proptosis due to mucormycosis in an immunocompromised patient. The patient was successfully managed medically without exenteration. The indications for exenteration are currently unclear, and no clinical guidelines exist.

Partial third nerve palsy involving the superior rectus and levator palpebrae muscles and distruption of central binocular vision fusion from brain stem infarction: a case report.

BACKGROUND AND PURPOSE: To add to the literature of a case of isolated third nerve paresis involving the nerve fascicles subserving the superior rectus and the levator palpebrae muslces from brain stem infarction and presenting the characteristics of central disruption of binocular vision fusional amplitudes. CASE REPORT: One patient with an old intracranial aneurysm and with old and recent brain stem infarcts and no other neurological manifestations, demonstrating findings characteristic of isolated paresis of the superior rectus and levator palpebrae muscles is reported. CONCLUSION: This dual involvement of the superior rectus and levator palpebrae muscles supports the anatomical arrangement of the ocular motor nucleus fascicles in the midbrain, clarified by experimental studies on animals and clinical data in humans and emphasizes the juxtaposition of the superior rectus and levator palpebrae fascicles and placing the levator palpebrae mucle fascicle lateral to the medial rectus fascicle in the midbrain. The comitant vertical deviation and the negative Bielschowsky head tilt test support the vertical rectus muscle involvement. The constant diplopia with only 4 prism diopters of hypotropia and with the absence of fusional amplitudes evokes disruption of central binocular fusion.

Tenon's capsule pseudo-tendon repair of a lost medial rectus muscle.

BACKGROUND AND PURPOSE: The loss of an extraocular muscle is an infrequent but serious complication of strabismus surgery. The purpose is to show that a tailored tongue of Tenon's capsule, 7.0 mm to 9.0 mm wide and 12.0 mm to 14.0 mm long, fashioned in the direction of a lost medial rectus muscle and attached at the site of its original insertion can restore full ocular movement in the direction of action of the muscle. CASE REPORT: Thisis a report of a patient who underwent re-shaping and attachment of Tenon's capsule to the original insertion of the medial rectus muscle that ruptured during attempted medial rectus recession for longstanding esotropia with medial rectus restriction. The procedure was done immediately following the loss and failure to retrieve the lost muscle. RESULTS: Residual large angle esotropia and good adduction were obtained postoperatively despite a severed and consecutively lost medial rectus muscle. CONCLUSION: A tongue of Tenon's capsule, attached at the original site of a lost extraocular rectus muscle in a young adult, works as a pseudo-tendon successfully restoring function in the direction of action of that muscle.