PALT (Partial Allogeneic Limbal Transplantation): A New Surgical Technique For Limbal Stem Cell Deficiency

PurposeLimbal stem cell deficiency (LSCD) is a rare but extremely relevant disease of the eye. LSCD patients often require a variety of surgical procedures, including keratoplasty in some cases. However, the outcome of these surgeries, including opacification and revascularization, is often frustrating due to LSCD relapse.MethodsWe developed a new surgical technique for the treatment of LSCD in which partial allogenic limbal transplantation (PALT) is carried out as part of penetrating keratoplasty (PK). After the PK, 1-8 slices from the limbal tissue of the donor graft are prepared and placed under the double running sutures attaching the corneal graft. This procedure was performed on 14 patients with LSCD, caused by severe ocular burn in 5 cases and by infection in 9. Between one and eight limbal transplants were used depending on the extension of the LSCD. ResultsAll 14 patients showed stable or increased visual acuity after the PALT surgery compared to their preoperative visual acuity. All of the grafts were integrated into the superficial corneal layers without progression of corneal vascularization beyond the limbal grafts. The median follow-up period was 12 months on average.ConclusionThe PALT method seems to be a promising surgical procedure for the treatment of patients with LSCD. It can be properly carried out in the context of keratoplasty and does not require a separate donor tissue. The PALT grafts may offer the possibility of constructing a new limbal region, resulting in stable or even increased visual acuity and the absence of corneal vascularization.

Bilateral Corneal Ghost Vessels in an Otherwise Healthy Child

We report a rare case of bilateral corneal ghost vessels in a 6–year-old child with an unremarkable past ocular and past medical history. This study was a single observational case report. A 6-year-old girl was referred to our clinic for further evaluation, due to suboptimal visual acuity in both eyes. Her past medical and ocular history revealed no systemic, inflammatory, infectious, or degenerative disorders. Slit-lamp examination revealed regressed blood vessels (“ghost vessels”) in the anterior and mid-corneal stroma as the only pathologic finding. Confocal scanning microscopy of both corneas demonstrated scattered branching railroad-shaped ghost vessels at the level of the middle and anterior stroma. Complete systemic workup was performed for the patient. No identifiable risk factor for the development of corneal vascularization was found. According to our findings, we assume that in our patient, vasculogenesis occurred due to angioblast invasion to the presumptive cornea due to disequilibrium in mechanisms involved in vascular patterning during embryonic development.

Amniotic membrane transplantation for infectious keratitis: a systematic review and meta-analysis

Infectious keratitis (IK) is the 5th leading cause of blindness globally. Broad-spectrum topical antimicrobial treatment is the current mainstay of treatment for IK, though adjuvant treatment or surgeries are often required in refractory cases of IK. This systematic review aimed to examine the effectiveness and safety of adjuvant amniotic membrane transplantation (AMT) for treating IK. Electronic databases, including MEDLINE, EMBASE and Cochrane Central, were searched for relevant articles. All clinical studies, including randomized controlled trials (RCTs), non-randomized controlled studies and case series (n > 5), were included. Primary outcome measure was time to complete corneal healing and secondary outcome measures included corrected-distance-visual-acuity (CDVA), uncorrected-distance-visual-acuity (UDVA), corneal vascularization and adverse events. A total of twenty-eight studies (including four RCTs) with 861 eyes were included. When compared to standard antimicrobial treatment alone, adjuvant AMT resulted in shorter mean time to complete corneal healing (− 4.08 days; 95% CI − 6.27 to − 1.88; p < 0.001) and better UDVA (− 0.26 logMAR; − 0.50 to − 0.02; p = 0.04) at 1 month follow-up in moderate-to-severe bacterial and fungal keratitis, with no significant difference in the risk of adverse events (risk ratio 0.80; 0.46–1.38; p = 0.42). One RCT demonstrated that adjuvant AMT resulted in better CDVA and less corneal vascularization at 6 months follow-up (both p < 0.001). None of the RCTs examined the use of adjuvant AMT in herpetic or Acanthamoeba keratitis, though the benefit was supported by a number of case series. In conclusion, AMT serves as a useful adjuvant therapy in improving corneal healing and visual outcome in bacterial and fungal keratitis (low-quality evidence). Further adequately powered, high-quality RCTs are required to ascertain its therapeutic potential, particularly for herpetic and Acanthamoeba keratitis. Future standardization of the core outcome set in IK-related trials would be invaluable.

Clinical Aspects of Amniotic Membrane Implants in Corneal Repair in Dogs with Complicated Ulcers

Background: Among numerous disorders treated by veterinary ophthalmology, therapies employed to solve corneal ulcers stand out. Amniotic membrane transplantation is an effective surgical technique for the treatment of complicated corneal ulcers in the dog, with highly satisfactory visual and cosmetic outcomes. However, in veterinary ophthalmology, reports on the use of the amniotic membrane and its corneal reconstructive potential are scarce. The objective of this work was to evaluate, for 21 days, the clinical aspects and the effectiveness of transplantation of canine amniotic membrane for corneal healing in two cases of complicated ulcers in dogs.Cases: Two Shih-Tzu dogs were diagnosed with complicated corneal ulcer. They underwent surgical treatment with the use of a glycerin-preserved canine amniotic membrane implant, which was secured on the cornea or the limbus. A surgical microscope at a magnification of 16x was used. The devitalized tissues at the periphery of the ulcer were excised, and multiple layers of amniotic membranes were sutured onto the cornea and near the limbus with interrupted absorbable suture. Protection of the canine amniotic membrane implants was performed with a scarified third eyelid flap, which was attached to the upper eyelid, and maintained for 14 days. During the first 14 days after the procedure, topical treatment with antibiotic eye drops was administered; protease inhibitors were also used. Antibiotics were used systemically for 10 days. Between days 14 and 21 after the transplantation procedure, protease inhibitors, corticosteroids, and lubricant were administered topically. Healing and clinical aspects were evaluated on days 0, 14, and 21. The parameters evaluated were blepharospasm, dazzle and direct pupillary reflexes, and consensual and threat responses. Corneal vascularization, hypopyon, synechia, opacity, and fluorescein dye penetration into the cornea were evaluated. The patient whose membrane was attached to the cornea was named COr, and the animal whose membrane was attached to the corneal limbus was named PLi. Blepharospasm and positive fluorescein test were detected only on the first day of the experiment; whereas, the dazzle and pupillary reflexes, as well as the consensual response, were present in both animals at all evaluated time points. Only COr exhibited hypopyon on day 0. Synechia was not observed in any of the animals at any of the time points. On the 21st day, COr exhibited deep vascularization and an opaque scar, while PLi exhibited only discrete vessels without blood perfusion, secondary to corneal repair.Discussion: A smooth operation of the central and peripheral ophthalmic system was maintained at all periods evaluated. The protection provided by the membrane contributed to corneal healing by reducing stimulation of nerve endings on the epithelium and stroma, and suppressing the blepharospasm reflex. The amniotic membrane used as an adjuvant has antimicrobial and anti-inflammatory properties, inhibits proteinases and mediators of inflammation, and exerts a mechanically protective effect. The corneal vascularization observed in both animals is related to the healing processes stimulated by filling the deep corneal lesions with the membrane. When used in addition to drug therapy, the amniotic membrane can inhibit postinflammatory neovascularization, fibroblast activity, collagen deposition, scarring, and opacifications. Accurate diagnosis, and correct therapeutic and surgical management, is fundamental for the successful treatment of corneal ulcers. In this work, canine amniotic membrane preserved in glycerin was used for the surgical treatment of complicated ulcers in dogs along with adequate clinical therapy. This was effective independent of the different anchorage techniques used, and led to satisfactory clinical results and short-term corneal healing.

Risk factors for occurrence and development of ulcerative keratitis in dogs

Ulcerative keratitis (corneal ulcer) is an inflammatory infected condition of the cornea with a violation of its epithelial layer, affecting the stroma. Due to the fact that the cornea is a tightly innervated tissue of the body, its damage is associated with the appearance of symptoms of varying intensity: hyperemia of the conjunctiva, blepharospasm, the corneal vascularization, a decrease or increase in tear production, the formation of superficial or deep sections of corneal epithelialization, depending on the severity and the duration of the pathological process. The causes of ulcerative keratitis are also diverse: corneal injuries, chronic conjunctivitis, dry keratoconjunctivitis, anomalies of the eyelids, brachiocephalic syndrome. The danger of ulcerative lesions of the cornea is due to their necrotic effect on eye tissue, possible perforation of the eyeball, the development of secondary glaucoma or uveitis, as well as panophthalmitis. It is necessary to establish risk factors for the occurrence and development of ulcerative keratitis in dogs to prevent this pathology in the future, since in the absence of timely diagnosis and treatment, the disease can progress and lead to impaired vision of the animal, thereby lowering the level of their quality of life. Determining the root cause of corneal ulcerative lesions is necessary to understand the possible outcome and relapse of the pathology, as well as the appointment of adequate treatment. Prevention and relief of the etiological factor of the disease and timely prescribed therapy lead to a decrease in the risk of development and complications of ulcerative keratitis.

Spontaneous Cataractous Lens Extrusion in a Patient with Corneal Melting

Purpose: The aim of this report is to describe an unusual case of cataractous lens extrusion through a diseased cornea in the absence of any history of trauma or surgery. Patient and Methods: An elderly female with a history of blepharitis, corneal vascularization, and scarring presented with foreign body sensation, mild ocular pain, and a brunescent cataractous lens extruding through an area of corneal melt of the right eye after being lost to follow-up. The patient was operated urgently and then referred to a specialized eye hospital for further management. Conclusion: In the setting of social neglect and poor compliance to treatment and appointments, consequences of common ophthalmic conditions can lead to serious vision and organ-threatening complications. These might require prompt medical and surgical attention.

Corneal crosslinking in septic melting corneal ulcers in dogs and cats

Objective of research. To evaluate the efficacy and safety of corneal collagen cross-linking during melting corneal ulcers in dogs and cats. Describe changes in the properties and structure of the cornea during the entire observation period. Materials and methods. 15 animals were included in the study: 8 dogs and 7 cats that received preliminary treatment for underlying disease, but without positive dynamics. All animals had an infectious-inflammatory process in the cornea with signs of keratomalacia. All animals underwent mechanical diepithelization of cornea with simultaneous surface surgical treatment of pathological tissues. CXL procedure was performed under general anesthesia with preliminary saturation of corneal stroma with riboflavin solution for 30 minutes. Results. All animals showed a decrease in purulent-inflammatory process 3...5 days after CXL. Keratomalacia inhibition was noted on average by 2 ... 3 days after procedure. By 7th day of observation, stabilization of wound process and epithelization of defect were observed in 11 animals. In 4 animals, this process lasted up to 10...12 days. In 13 animals, we observed active corneal vascularization by the 14th day after CXL. In 2 animals, regeneration process was avascular. By 30th day of observation, 13 animals showed complete healing of corneal defect zone with formation of fibrosis and slight vascularization, of which 4 dogs had partial deposition of pigment in defect zone. And 1 cat on 15th day had a perforation of cornea with iris prolapse and subsequent evisceration. Conclusion. This study shows that CXL is effective in animals with infectious keratitis, accompanied by keratomalacia. These results allow us to offer CXL as an alternative to surgical methods of treatment. This method is safe for structures of eye while observing recommended protocols, which was confirmed in our work. However, given small number of patients, further research is required to select optimal combination treatment regimen.

A Rare Case report of Ichthyosis Follicularis, Alopecia and Photophobia (IFAP) Syndrome with developmental cataract

Purpose: The IFAP syndrome is a rare X-linked genetic disorder with only 40 reported cases worldwide. We report a 23 year old, male patient with classical IFAP syndrome. Method: Descriptive single case report. Case: 23 years old male patient, presented with ocular findings of photophobia, cornealinfiltrate, superior corneal vascularization and astigmatism along with dermatological manifestations. Result: Photophobia was pathognomonic in a patient presenting with Icthyosisfollicularis and alopecia. Associated ocular findings were corneal infiltrate, superior corneal vascularization, angio regression with pericytic infilterate and Astigmatism. Our patient also presented with bilateral developmental cataract. Conclusion: Developmental cataract can be a primary manifestation with IFAP syndrome. Corneal infiltrates with photophobia as the only presenting symptom can be a rare finding associated with rare skin disorders like IFAP syndrome. They are also the most challenging symptoms to manage.