Dense Corneal Opacity Research Articles

A safer alternative approach to penetrating keratoplasty in opaque corneas

Background:This video demonstrates a useful technique of keratoplasty which can be routinely undertaken by all surgeons when imaging modalities such as anterior segment optical coherence tomography are not available and prior patient history is not forthcoming.Purpose:To demonstrate a technique of lamellar separation and layer by layer removal of host cornea when dealing with keratoplasty in perforated corneal ulcers, adherent leucomas, dense corneal opacities, which obscure visualization of the iris and anterior chamber details.Synopsis:In this video, we demonstrate penetrating keratoplasty in a failed opacified graft with iridocorneal adhesions, with no visualization of anterior chamber details. Lamellar dissection of the host cornea is done starting at its periphery and moving centrally, with gentle peeling of the superficial layers, the epithelium and bulk of stroma, following which, the deeper portion of the cornea is dissected and separated from underlying adherent iris tissue. Layer by layer separation allows better visualization through the remaining thin layers of the cornea. This permits fine dissection and layered removal of the cornea, thereby avoiding injury to iris and lens. Debulking of the host cornea decreases the force that is needed to be applied to separate adherent iris tissue from the host cornea, and reduces the chances of sudden entry into the anterior chamber and subsequent damage to the iris or lens. This also reduces the chance of iris tears, iridodialysis and bleeding from the iris and helps maintain iris integrity, which is essential intraoperatively for protection of lens and anterior chamber formation, and to avoid glare and photophobia postoperatively. Preventing iris damage also reduces the chances of formation of peripheral anterior synechiae (PAS), which can predispose to graft rejection, graft failure and secondary glaucoma.Highlights:Layer by layer corneal separation beginning inside the graft host junction, careful separation of iridocorneal adhesions and PAS is a helpful technique to optimally preserve the anterior segment anatomy during difficult cases of penetrating keratoplasty.Online Video Link: https://youtu.be/ZmQQhuOnAh4

The 3-year outcomes of corneal tattooing for severely disfigured corneas.

To evaluate the efficacy of corneal tattooing for various clinical applications. The medical charts of 62 eyes of 62 patients who underwent corneal tattooing between March 2016 and August 2017 were retrospectively reviewed. The causes of opacity and various methods of corneal tattooing were analyzed. Among our 62 patients, 38 were males and 24 were females. Average age was 48.47 ± 15.30 (range, 12-74) years old. The mean follow-up period was 40.19 ± 2.34 (range, 36-43) months. The most common causes of corneal opacity were ocular trauma (33 eyes, 53.2%), prior retinal surgery (9 eyes, 14.5%), congenital etiologies (8 eyes, 12.9%) and measles (5 eyes, 8.0%). The most common associated ocular findings were strabismus (23 eyes, 37.0%), phthisis bulbi (17 eyes, 27.4%) and band keratopathy (13 eyes, 20.9%). Cosmetic outcomes improved without serious complications in all cases. Corneal tattooing is a viable option with an expanding set of indications, such as discolored previous corneal tattoos, white pupil due to inoperable cataract with clear cornea and dense corneal opacities in blind eyes. Elective corneal tattooing seems to be a viable and convenient method to improve cosmesis with minimal complications and high patient satisfaction.

En-Bloc Resection Versus Resection After Evacuation and Suction of the Content for Orbital Optic Nerve Glioma Causing Visual Loss and Disfiguring Proptosis.

To evaluate the surgical outcomes of two different techniques of resection for optic nerve gliomas confined to the intra-orbital segment. This prospective, comparable, clinical interventional case series was conducted at the orbital clinic of Assiut University Hospital, the referral centre of Upper Egypt in the period between 2006 and 2018. The study included 10 children with optic nerve gliomas confined to the intra-orbital part without intracanalicular or intracranial extension and causing severe visual loss and disfiguring proptosis. In all cases, lateral orbitotomy was performed to expose the mass. In 5 cases (group A), the glioma was resected en-bloc. In 5 cases (group B), a new technique of resection was introduced. The wall of the glioma was incised, the content was evacuated and suctioned and followed by resection under good visualization of the markedly reduced mass in size. In the 2 groups, no tumour regrowth was reported during the follow-up period of 3-12 years. In group A, the 5 cases developed postoperative third nerve damage with paralytic ptosis and one case had severe neurotrophic keratitis ended by dense corneal opacity. In group B, a healthy ipsilateral eye was preserved in all cases and no one case developed postoperative paralytic ptosis. Reduction of size of an intra-orbital optic nerve glioma by evacuation and suction of the content before resection is highly recommended. This makes the surgical field during resection more visible and minimizes the possibility of third or other nerves damage.

Developmental glaucoma in a patient of ectrodactyly-ectodermal dysplasia.

A 23-year-old Indian female, already on intraocular pressure (IOP) lowering eye drops was referred for control of IOP. Systemic involvement was marked for coarse facial features [Fig. 1a], dental and skeletal abnormalities [Fig. 1c-g] suggestive of ectrodactyly-ectodermal dysplasia (EED). The right eye was in exotropia with no perception of light. The left eye had generalized nebular corneal opacification [Fig. 1b], wide-angle recess with numerous iris processes on gonioscopy, and visual acuity of 20/800. Applanation IOP was 28 mm Hg in the right eye and 46 mm Hg in left eye. Pachymetry and axial lengths were 523 μm and 24.32 mm, respectively in the left eye. Hazy view of fundus revealed glaucomatous optic disc changes.Figure 1: (a) Coarse facial features. (b) Dense corneal opacity in the right eye and the left eye with hazy cornea. (c) Oligodontia. (d) Orthopantomograph showing oligodontia with underdeveloped alveolar bone. (e and f) Ectrodactyly of hands. (g) Ectrodactyly and syndactyly of feetAfter lowering IOP with oral acetazolamide, Ahmed glaucoma valve FP7 (New World Medical, Inc CA) was implanted in superotemporal quadrant. The tube was placed in in the anterior chamber. At 4 months, full-thickness penetrating keratoplasty (PK) was done. In the early postoperative period vision was 20/1000 and IOP varied between 6 to 9 mm Hg [Fig. 2a]. At 7 months follow-up after PK, best-corrected visual acuity (BCVA) was 20/80 [Fig. 2b]. The corneal graft was clear but cataractous changes were noticed [Fig. 2c]. The IOP was 16 mm Hg, and the tube was well placed in the anterior chamber [Fig. 2d] with diffuse functional bleb [Fig. 2e]. The left eye fundus examination revealed average-sized disc with vertical cup-to-disc ratio of 0.75 and inferior rim thinning [Fig. 2f]. At 18-month follow-up, graft was clear, BCVA was 20/50, and IOP was 16 mmHg.Figure 2: (a) Some edema of the graft 1-week post-keratoplasty (b) Clear graft at 7-month follow-up (c) Clinically significant cataract. (d) Ahmed glaucoma valve FP7 tube in situ (white arrow) in the anterior chamber. (e) Bleb (red arrow). (f) Fundus photo depicting glaucomatous cupping in the left eyeDiscussion The reported ocular involvement in EED includes telecanthus, blepharophimosis, entropion, meibomian gland absence, atresia of lacrimal outflow tract components, ocular surface and tear film disorders, and keratopathy.[12] Infantile glaucoma has been reported with ectodermal dysplasia.[3] The absence of iris anomalies and presence of ectrodactyly differentiate this case from Axenfeld-Rieger syndrome.[4] Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Histopathological Studies on Rabbits Infected by Bacteria Causing Infectious Keratitis in Human through Eye Inoculation.

This study aimed to investigate the pathogenic effect of bacteria causing infectious keratitis among patients through experimental study conducted on rabbits' eyes with the aid of histopathology as eye infection is a common disease in developing countries that may complicate to loss of vision. 100 swab samples were collected from human infected eyes, at Qassim region during 2012, for the isolation of Pseudomonas aeruginosa and Staphylococcus aureus. The isolated pathogenic bacteria were tested to various antibiotics using some selected antibiotics discs through agar-well diffusion method. Then, experimental study conducted on 27 rabbits. The rabbits were divided randomly into three equal groups, each containing 9 rabbits. Rabbits of group (1) served as control group (Negative Control) and their eyes were inoculated with the buffer only. Rabbits of group (2) were inoculated through eyes with the isolated Pseudomonas aeruginosa. Rabbits of group (3) were inoculated through eyes with the isolated Staphylococcus aureus. Out of 100 collected swab samples from human infected eyes, Pseudomonas aeruginosa and Staphylococcus aureus were isolated with a total percentage of 25.21% and 15.65%; respectively and used in this study. Both bacterial isolates were sensitive to Gentamicin and Cefuroxime. Clinically, experimentally infected rabbits by Pseudomonas aeruginosa, revealed varying degree corneal abrasions, corneal abscess and dense corneal opacity. Histopathologically, at 3(rd) day post-infection (PI), the cornea revealed polymorpho-nuclear cells infiltration with loss of the outer epithelial lining. At 7(th) day PI, neutrophils were seen in the stroma. At 15(th) day PI, proliferation of fibroblasts and new vascularisation were seen in the stroma. Clinically, rabbits experimentally infected with Staphylococcus aureus, revealed corneal ulcers and focal abscesses. Histopathologically, at 3(rd) and 7(th) day PI, the cornea revealed edema and infiltration of leukocytes. At 15(th) day PI, hyperplasia of corneal epithelium and proliferation of keratocytes were evident. The liver and kidneys of experimented rabbits revealed no remarkable histopathological alterations along the period of experiment. Pseudomonas aeruginosa and Staphylococcus aureus are common eye infection in human, both induced severe lesions in the eyes of rabbits that could interfere with vision, therefore, strict measures to control these infections in human is recommended.

Spontaneous Resolution of Cataract and Medical Management of Corneal Opacity in an Indian Parrot—<i>Psittacula krameri manillensis</i>

A 35-year-old Indian parrot (Psittacula krameri manillensis) was presented to the Department of Veterinary Surgery & Radiology, West Bengal University of Animal and Fishery Sciences with a history of blepharospasm and corneal lesion OS. Test with fluorescein dye was negative. The dense corneal opacity (macula) was identified as involving the posterior corneal layer. The further ophthalmic examination was done and hypermature phacolytic cataract was diagnosed. No other abnormality was detected. Medical management with topical nepafenac prednisolone and triple antibiotic was instituted. The corneal lesion subsided completely within one week followed by spontaneous resorption of the cataract. The treatment protocol was successfully eliminated the discomfort and intraocular lesions in the senile parrot.

Femtosecond laser‐assisted penetrating re‐keratoplasty

Editor, Penetrating keratoplasty has usually been performed taking a trephine for the sagittal excision of the corneal donor button and for the preparation of the recipient corneal bed. The disadvantages of this sagittal cutting technique are a lack of rotational stability and a lack of sagittal stability. With the introduction of the femtosecond laser into clinical ophthalmology (Jonas & Vossmerbaeumer 2004; Hoffart et al. 2008; Mastropasqua et al. 2008; Por et al. 2008; Price & Price 2008), a new cutting technique has emerged that offers the possibility of creating non-circular and angled incisions. According to preliminary results, this new technique can markedly reduce postoperative keratoplasty and enhance the overall stability of the wound because of the increased and angled surface of the interface between the graft and the host tissue. Because the femtosecond laser is based on an optical principle with the laser beam penetrating the corneal tissue, it necessitates sufficient transparency of the corneal stroma to allow the laser beam to penetrate to the deep corneal layer and Descemet’s membrane. Previous studies have shown that an intrastromal corneal oedema caused by a corneal endothelial insufficiency has not been an obstacle for the femtosecond laser beam (Hoffart et al. 2008; Por et al. 2008; Price & Price 2008). However, so far it has been unclear whether dense intracorneal scars, particularly after previous corneal surgery, may prevent the use of the femtosecond laser for keratoplasty. Therefore, in this article I report on the feasibility of the technique for a patient who underwent femtosecond laser keratoplasty after a previous keratoplasty had failed. A 48-year-old patient had undergone conventional trephine-guided penetrating keratoplasty as treatment of keratoconus in 1991. The diameter of the graft trephined from the endothelial side was 8.0 mm; the diameter of the excised corneal button in the host cornea was 7.8 mm. The graft was centred onto the optical axis. With an initially clear corneal graft, best-corrected visual acuity was 20/20. Seventeen years after the keratoplasty, the graft started to develop intrastromal oedema, particularly in the late afternoon, because of a progressive age-related insufficiency of the corneal endothelium of the graft. Using a commercially available femtosecond laser (Advanced Medical Optics; Intralase, Santa Ana, California, USA), a penetrating rekeratoplasty was carried out. A top-hat cutting configuration (Price & Price 2008) was chosen. The diameters of the superficial and deep parts were 7.0 mm and 8.5 mm, respectively; a lamellar cut was made at a depth of 250 μm. The lamellar overlapped the superficial part and the deep part by 0.3 mm, so that its outer diameter was 8.8 mm and its inner diameter was 6.7 mm. As per the previous corneal graft, the regraft was centred onto the optical axis. Despite the dense corneal opacities in the zone of the interface between the previous graft and the host cornea, the femtosecond laser was able to cut the corneal tissue unremarkably. The central corneal button precut by the laser could be removed without further use of a knife or scissors. The graft was fixated with a double running suture with buried knots in the interface (Fig. 1). Three months after the intervention, visual acuity was 20/20 with a regular corneal astigmatism of 2.0 dioptres (Fig. 1). Clinical photograph showing an eye 3 months after a femtosecond laser-assisted penetrating homologous keratoplasty 17 years after a previous penetrating keratoplasty. The scar of the interface between the former graft and the recipient cornea (remnants of the former scar: arrows) did not impede the femtosecond laser cutting of the cornea. These results suggest that the femtosecond laser is able to perform incisions in the superficial and deep corneal layers including Descemet’s membrane through dense intracorneal opacities such as scars in the interface after a previous penetrating keratoplasty. A previous keratoplasty is not a contradiction against a femtosecond laser-assisted keratoplasty.

Acute Corneal Calcification Following Chemical Injury

To describe the clinical and ultrastructural features of 3 cases of acute corneal calcification following accidental chemical injury. Three men presented over an 18-month period with unilateral eye injuries sustained when applying an industrial fire retardant. This product is predominantly a gypsum aggregate (calcium sulfate dihydrate) plaster combined under pressure with a set-time accelerator (aluminum sulfate). In each case the tear pH was initially alkaline, and the eyes were irrigated with phosphate-buffered saline according to protocol. Within hours a dense corneal opacity had developed that showed only minor resolution over 3 years of follow-up. Two eyes required corneal graft surgery for visual rehabilitation. Light and electron microscopy and energy dispersive analysis of x-rays (EDAX) was performed on excised tissue. Light and electron microscopy showed dense mineralization of the anterior stroma with discrete crystalline deposits in the deeper stroma. EDAX of the crystals showed high emission peaks for calcium and phosphorus. The insolubility, elemental composition, and ultrastructural appearance suggest that the opacity was caused by calcium phosphate deposition. The absence of phosphorus from the listed components of the fire retardant suggests that the use of phosphate-buffered irrigation fluid or the subsequent use of phosphate-buffered drops may have contributed to the deposition of this insoluble crystalline deposit.

Deep lamellar keratoplasty combined with cataract surgery.

We used a surgical technique that combines deep lamellar keratoplasty, phacoemulsification, and intraocular lens implantation for treating patients with cataract and corneal stromal disease. Deep lamellar dissection of the cornea was first performed with viscoelastic substances (hyaluronate sodium) until the highly transparent Descemet membrane solely remained. We then created a short corneal tunnel to perform phacoemulsification with low vacuum and intraocular lens implantation. The resilience of the Descemet membrane ensured excellent viewing of the whole anterior chamber as well as the surgical conditions of a closed system. At the end of surgery, a full-thickness donor button was sutured into the recipient bed after its Descemet membrane was stripped. This technique was effective in these 4 patients with cataract and dense corneal opacity.

Temporary graft for closed-system cataract surgery during corneal triple procedures

Performing phacoemulsification during a triple corneal procedure has many advantages. Operating in a closed chamber makes surgery easier and safer. In some cases, however, a dense corneal opacity may prevent closed-chamber surgery, necessitating the use of an open-sky technique. In these cases, a temporary corneal graft using a corneal button not suitable for penetrating keratoplasty is proposed to allow phacoemulsification and foldable intraocular lens implantation through a corneal tunnel. The temporary corneal graft is replaced with a permanent graft after these steps are completed. This technique was effective in 3 patients with cataract and dense corneal opacity.

Unusual corneal deposit after the topical use of cyclosporine as eyedrops

PURPOSE: To report a patient who developed bilateral corneal opacities 5 days after the beginning topical cyclosporine. METHODS: Case report. A 45-year-old woman with graft-versus-host disease presented with bilateral corneal deposits. She had been treated with topical physiological saline solution, sodium hyaluronate, ofloxacin, fluorometholone, and oxybuprocaine. Cyclosporine eyedrops were added for persistent corneal epithelial defect bilaterally. Five days after cyclosporine, she complained of visual loss and dense corneal opacities were detected that covered the pupil bilaterally. RESULTS: Deposits were also observed on the punctal plugs, and infrared spectroscopy and X-ray analysis showed that these deposits had properties of cyclosporine. CONCLUSION: Topical cyclosporine, alone or in combination with other eyedrops, may cause severe corneal deposits in patients with disturbance of the corneal epithelial barrier and decreased tear clearance.

Ultrasound Biomicroscopy in Infantile Glaucoma

Glaucoma in infants has many causes: Evaluation of the anatomy of the anterior segment of eyes with infantile glaucoma may help to determine the pathogenesis of an infant's disease and influence therapeutic decisions. Eleven eyes of six infants with glaucoma were evaluated with ultrasound biomicroscopy (UBM) to evaluate the anatomic characteristics and relationships of the anterior segment structures. The anterior chamber angle, iris, lens, ciliary body, and posterior chamber angle could be imaged in detail. Elongated and anteriorly placed ciliary processes were noted in all eight eyes with trabeculodysgenesis. There were no apparent anomalies in the trabecular meshwork, or anterior chamber. In three eyes with dense corneal opacities, ultrasound biomicroscopy showed severe anterior segment disorganization and thin central corneas with posterior corneal excavation. Ultrasound biomicroscopy is a useful non-invasive method for evaluating infants with glaucoma in cases with corneal opacities. This information can help in surgical planning for glaucoma management.

Two Novel Molecular Defects in theLCATGene Are Associated With Fish Eye Disease

A 53-year-old man with a severely reduced HDL cholesterol level, dense corneal opacities, normal renal function, and premature coronary artery disease was investigated together with 16 members of his family. The proband was diagnosed with fish eye disease. As in previously reported patients with fish eye disease, the endogenous plasma cholesterol esterification rate was near normal, yet lecithin:cholesterol acyltransferase (LCAT) activity was almost absent when measured with exogenous HDL analogues used as substrate. Direct sequencing of the LCAT gene revealed two novel missense mutations in exon 1 and exon 4, resulting in the substitution of Pro10 with Gln (P10Q) and Arg135 with Gln (R135Q), respectively. Both missense mutations were located on different alleles. Genetic analysis by polymerase chain reaction revealed 4 carriers of the P10Q and 3 carriers of the R135Q defect. Functional assessment of both missense mutations revealed that when exogenous HDL analogues were used as substrate, the specific activity of rLCAT p10Q was 18% of wild type (WT); however, when LDL was used as substrate, the activity was 146% of WT. By contrast, rLCATR135Q was inactive against both substrates. Thus, we conclude that the LCATR135D mutation is causative for complete LCAT deficiency and that the clinical phenotype of fish eye disease seen in this patient is due to the Pro10 mutation. The presence of premature coronary artery disease in the absence of other risk factors in this new case of fish eye disease raises questions regarding the risk of atherosclerosis, which has previously been reported to be nonexistent.

High-Resolution Ultrasound Biomicroscopy of the Anterior Segment in Patients With Dense Corneal Scars

Preoperative evaluation and surgical planning for penetrating keratoplasty in patients with dense corneal scars is often difficult because of poor visualization of the anterior segment. We performed ultrasound biomicroscopy (50-megahertz frequency, 50-micron resolution) on five eyes of five patients with dense corneal opacities of different etiologies to evaluate the anatomic relationships of the iris, lens, angle, and ciliary body. Corneal thickness, the presence or absence of iridocorneal adhesions, peripheral anterior synechiae, and cyclitic membranes, intraocular lens position, and relationships among intraocular structures could be evaluated in vivo. Ultrasound biomicroscopy is the optimal method of obtaining reliable, high-resolution images delineating anatomic relationships and pathology in the anterior segment. This information aids in surgical planning for penetrating keratoplasty and anterior segment reconstruction.

Primary Lipidic Degeneration of the Cornea

Light-microscopic and transmission-electron-microscopic studies were performed on corneal buttons obtained after keratoplasty from a 68-year-old white woman who had presented with decreasing visual acuity secondary to bilateral dense corneal opacities. We found lipidic material diffusely and densely distributed extracellularly in the posterior and inferior aspect of the corneal stroma, with no evidence of corneal vascularization and no serum lipid elevation. There was no known involvement of other family members. The findings support the concept that primary lipidic degeneration of the cornea represents an exaggeration of arcus senilis.

Implantation of collagen punctal plugs for the reduction of post-keratoplasty ametropia

In 1995, a 46-year-old woman was referred for refractive surgery. Eleven years earlier, she had undergone an uncomplicated penetrating keratoplasty in her right eye to treat a dense corneal opacity caused by contact lens-related microbial keratitis. Due to high myopia in the graft, she was unable to achieve useful vision and declined contact lens use. After extensive counseling, she elected to undergo radial keratotomy (RK) and arcuate keratotomy (AK) in her right eye. We recommended the insertion of collagen punctal plugs into the keratotomy incisions to increase the RK effect. She also decided to have RK in her left eye. Postoperatively, her uncorrected visual acuity was 20/25 OD and 20/30 OS. We were able to contact her and her ophthalmologist eleven years later, and eight of eleven collagen plugs were still present in the incisions, with no signs of rejection or inflammation. Later, we learned that she underwent a repeat penetrating keratoplasty due to corneal graft failure after a phacoemulsification procedure. The pathologic examination of the intact plugs and graft also showed no rejection or inflammation.