Penetrating keratoplasty in children under 3 years old with congenital corneal opacities

AIM: To evaluate the graft rejection and visual outcomes after penetrating keratoplasty (PK) in the presence of various congenital corneal opacities in children. METHODS: In this retrospective cohort study, children who underwent PK were then followed for 5y. The patient's medical records were collected from June 2014 until June 2019 and analyzed in December 2019. All patients were children under three years old with congenital corneal opacities with or without microcornea who came to a pediatric ophthalmologist and underwent PK in Jakarta Eye Center (JEC). Beforehand, all children have participated in a thorough evaluation for PK. In the case of severe microcornea was not advised to undergo surgery. The visual outcomes and graft survival rate were described in percentages. The graft survival plot was presented with Kaplan-Meier, while the visual acuity was analyzed using the Wilcoxon signed ranks test. RESULTS: Sixteen eyes from eleven patients (seven girls and four boys) underwent PK. The graft survival rate of the first 6, 12, and 18 mo later of keratoplasty was 100%, 83.3%, and 66.7%, respectively. The overall mean survival time is 22mo (standard error 2.419), and no significant difference between the patients underwent PK before and after 36mo of their age (P=0.52). The graft failure was 50%, and post-surgery complications included cataract 43.7%, band keratopathy 12.5%, and scleromalasia 6.25%. Wilcoxon test analysis of visual acuity post keratoplasty was not statistically significant (P=0.34), while overall showed 44% improvements of visual outcome for 5y of follow-up. With a good survival at one year up to 22mo (83.3%), the visual acuity could be achieved (63%), and showed improvements (44%) during follow-up. CONCLUSION: The complications are frequent for pediatric PK. Thus, corneal surgery on infants requires careful case selection, adequate pre-operative evaluation, skilled surgery (optical correction), very close cooperation family–physician, intensive post-operation care, and amblyopia management in the future.

Three-Axis Tension-Measuring Vitreoretinal Forceps Using Strain Sensor for Corneal Surgery

Precise motion control is important in robotic surgery, especially corneal surgery. This paper develops a new tension-measurement system for forceps used in corneal surgery, wherein contact force is applied only to a specific location for precise control, with precise movements detected by attaching a nano-crack sensor to the corresponding part. The nano-crack sensor used here customizes the working range and sensor sensitivity to match the strain rate of the tip of the forceps. Therefore, the tension in the suture can be sufficiently measured even at suture failure. The printed circuit board attached to the bottom of the system is designed to simultaneously collect data from several sensors, visualizing the direction and magnitude of the tension in order to inform the surgeon of how much tension is being applied. This system was verified by performing pig-corneal suturing.

The Clinical Guiding Role of the Distribution of Corneal Nerves in the Selection of Incision for Penetrating Corneal Surgery in Canines

The cornea is one of the regions with the highest density of nerve terminals in the animal body and it bears such functions as nourishing the cornea and maintaining corneal sensation. In veterinary clinical practice, the corneoscleral limbus incision is frequently applied in cataract surgery, peripheral iridectomy, and other procedures for glaucoma. Inevitably, it would cause damage to the nerve roots that enter the cornea from the corneal limbus, thus inducing a series of complications. In this paper, the in vitro cornea (39 corneas from 23 canines, with ages ranging from 8 months old to 3 years old, including 12 male canines and 11 female canines) was divided into 6 zones, and the whole cornea was stained with gold chloride. After staining, corneal nerves formed neural networks at different levels of cornea. There was no significant difference in the number of nerve roots at the corneoscleral limbus between different zones (F = 1.983, p = 0.082), and the nerve roots at the corneoscleral limbus (mean value, 24.43; 95% CI, 23.43–25.42) were evenly distributed. Additionally, there was no significant difference in the number of corneal nerve roots between male and female canines (p = 0.143). There was also no significant difference in the number of corneal nerve roots between adult canines and puppies (p = 0.324). The results of the above analysis will provide a reasonable anatomical basis for selecting the incision location and orientation of penetrating surgery for the canine cornea in veterinary practice.

Quantification of biomechanical properties of human corneal scar using acoustic radiation force optical coherence elastography

Biomechanical properties of corneal scar are strongly correlated with many corneal diseases and some types of corneal surgery, however, there is no elasticity information available about corneal scar to date. Here, we proposed an acoustic radiation force optical coherence elastography system to evaluate corneal scar elasticity. Elasticity quantification was first conducted on ex vivo rabbit corneas, and the results validate the efficacy of our system. Then, experiments were performed on an ex vivo human scarred cornea, where the structural features, the elastic wave propagations, and the corresponding Young’s modulus of both the scarred region and the normal region were achieved and based on this, 2D spatial distribution of Young’s modulus of the scarred cornea was depicted. Up to our knowledge, we realized the first elasticity quantification of corneal scar, which may provide a potent tool to promote clinical research on the disorders and surgery of the cornea.

Corneal Surgery in the Cat: Diseases, considerations and techniques

Practical relevance: The ability to recognize, diagnose and treat corneal disease is essential for maintaining vision and comfort in feline patients. Being able to correctly identify appropriate techniques for surgical cases is of particular importance for success when performing corneal surgery. Clinical challenges: Many different corneal diseases present with similar clinical signs, and it can be hard to determine the appropriate treatment for individual patients. It is essential for the clinician to understand the indications for corneal surgery, instrumentation needed and microsurgical principles prior to attempting these procedures. The prognosis following surgery and potential complications should be discussed with the client. Audience: This review article aims to assist in decision-making and to provide detailed guidance for primary care clinicians considering referral of cats for corneal surgery. The review outlines common feline corneal diseases and associated surgical therapies performed by veterinary ophthalmologists, highlighting appropriate instrumentation and case selection. Some surgeries are explained in depth for ophthalmologists and residents in training. Equipment: Although some procedures may be performed with common surgical equipment and supplies, most require specialized ophthalmic instrumentation and expertise, which entails significant microsurgical training and practice, as well as financial investment. Most of the procedures require an operating microscope for the best surgical outcomes; however, surgical loupes may be sufficient in some cases. Evidence base: This review article compiles information from many published references on feline corneal diseases and surgeries, complemented by the experience of the authors.

Unilateral Corneal Insult Also Alters Sensory Nerve Activity in the Contralateral Eye

After the unilateral inflammation or nerve lesion of the ocular surface, the ipsilateral corneal sensory nerve activity is activated and sensitized, evoking ocular discomfort, irritation, and pain referred to the affected eye. Nonetheless, some patients with unilateral ocular inflammation, infection, or surgery also reported discomfort and pain in the contralateral eye. We explored the possibility that such altered sensations in the non-affected eye are due to the changes in their corneal sensory nerve activity in the contralateral, not directly affected eye. To test that hypothesis, we recorded the impulse activity of the corneal mechano- and polymodal nociceptor and cold thermoreceptor nerve terminals in both eyes of guinea pigs, subjected unilaterally to three different experimental conditions (UV-induced photokeratitis, microkeratome corneal surgery, and chronic tear deficiency caused by removal of the main lacrimal gland), and in eyes of naïve animals ex vivo. Overall, after unilateral eye damage, the corneal sensory nerve activity appeared to be also altered in the contralateral eye. Compared with the naïve guinea pigs, animals with unilateral UV-induced mild corneal inflammation, showed on both eyes an inhibition of the spontaneous and stimulus-evoked activity of cold thermoreceptors, and increased activity in nociceptors affecting both the ipsilateral and the contralateral eye. Unilateral microkeratome surgery affected the activity of nociceptors mostly, inducing sensitization in both eyes. The removal of the main lacrimal gland reduced tear volume and increased the cold thermoreceptor activity in both eyes. This is the first direct demonstration that unilateral corneal nerve lesion, especially ocular surface inflammation, functionally affects the activity of the different types of corneal sensory nerves in both the ipsilateral and contralateral eyes. The mechanisms underlying the contralateral affectation of sensory nerves remain to be determined, although available data support the involvement of neuroimmune interactions. The parallel alteration of nerve activity in contralateral eyes has two main implications: a) in the experimental design of both preclinical and clinical studies, where the contralateral eyes cannot be considered as a control; and, b) in the clinical practice, where clinicians must consider the convenience of treating both eyes of patients with unilateral ocular conditions to avoid pain and secondary undesirable effects in the fellow eye.

Clinical Characteristics and Outcomes of Fungal Keratitis in the United Kingdom 2011–2020: A 10-Year Study

Fungal keratitis (FK) is a serious ocular infection that often poses significant diagnostic and therapeutic dilemmas. This study aimed to examine the causes, clinical characteristics, outcomes, and prognostic factors of FK in the UK. All culture-positive and culture-negative presumed FK (with complete data) that presented to Queen’s Medical Centre, Nottingham, and the Queen Victoria Hospital, East Grinstead, between 2011 and 2020 were included. We included 117 patients (n = 117 eyes) with FK in this study. The mean age was 59.0 ± 19.6 years (range, 4–92 years) and 51.3% of patients were female. Fifty-three fungal isolates were identified from 52 (44.4%) culture-positive cases, with Candida spp. (33, 62.3%), Fusarium spp. (9, 17.0%), and Aspergillus spp. (5, 9.4%) being the most common organisms. Ocular surface disease (60, 51.3%), prior corneal surgery (44, 37.6%), and systemic immunosuppression (42, 35.9%) were the three most common risk factors. Hospitalisation for intensive treatment was required for 95 (81.2%) patients, with a duration of 18.9 ± 16.3 days. Sixty-six (56.4%) patients required additional surgical interventions for eradicating the infection. Emergency therapeutic/tectonic keratoplasty was performed in 29 (24.8%) cases, though 13 (44.8%) of them failed at final follow-up. The final corrected-distance-visual-acuity (CDVA) was 1.67 ± 1.08 logMAR. Multivariable logistic regression analyses demonstrated increased age, large infiltrate size (>3 mm), and poor presenting CDVA (<1.0 logMAR) as significant negative predictive factors for poor visual outcome (CDVA of <1.0 logMAR) and poor corneal healing (>60 days of healing time or occurrence of corneal perforation requiring emergency keratoplasty; all p < 0.05). In conclusion, FK represents a difficult-to-treat ocular infection that often results in poor visual outcomes, with a high need for surgical interventions. Innovative treatment strategies are urgently required to tackle this unmet need.

Structure of ophthalmic pathology according to S. Fyodorov Eye Microsurgery Federal State Institution and development of innovative technologies

The article discusses the structure of ophthalmic pathology. These results are based on the analysis of statistical data of a large number of patients of the S. Fyodorov Eye Microsurgery Federal State Institution in 2019 (year before COVID-19 pandemic). In 2019 – 565988 patients were registered in medical database of our institution for the first time. The distribution of ophthalmic pathology among these patients was as follows. Cataract – 25.0%, including complicated cataract 15.9 %. Glaucoma – 3.1%; Vitreoretinal pathology – 8.2%; Diabetes – 2.9%; Oculoplastic pathology – 2.7%; Oncology – 1.1%; Eye diseases in children – 12.9%; Refractive errors – 17.2%; Diseases of the eye fundus – 12.6 %; Corneal pathology – 2.2%; Inflammatory diseases – 10.3%; Other diseases – 1.8 %. The article carefully describes the innovative technologies and the main trends that determine the overall development of such areas of ophthalmic surgery as: cataract surgery, glaucoma, corneal surgery, vitreoretinal surgery, laser refractive surgery, laser surgery of the retina and vitreous body, surgical manipulations in children, oculoplasty, ophthalmooncology. Key words: structure of ophthalmic pathology, innovative technologies of ophthalmic surgery, main trends of ophthalmic surgery.

Clinical Characteristics and Outcomes of Fungal Keratitis in the United Kingdom 2011-2020: A 10-Year Study

Fungal keratitis (FK) is a serious ocular infection that often poses significant diagnostic and therapeutic dilemmas. This study aimed to examine the causes, clinical characteristics, outcomes, and prognostic factors of FK in the UK. All culture-positive and culture-negative presumed FK (with complete data) that presented to Queen&rsquo;s Medical Centre, Nottingham, and Queen Victoria Hospital, East Grinstead, between 2011 and 2020 were included. A total of 117 patients (n=117 eyes) with FK were included in this study. The mean age was 59.0&plusmn;19.6 years (range, 4-92 years) and 51.3% patients were female. Fifty-three fungal isolates were identified from 52 (44.4%) culture-positive cases, with Candida spp. (33, 62.3%), Fusarium spp. (9, 17.0%), and Aspergillus spp. (5, 9.4%) being the most common organisms. Ocular surface disease (60, 51.3%), prior corneal surgery (44, 37.6%), and systemic immunosuppression (42, 35.9%) were the three most common risk factors. Hospitalisation for intensive treatment was required for 95 (81.2%) patients, with a duration of 18.9&plusmn;16.3 days. Sixty-six (56.4%) patients required additional surgical interventions for eradicating the infection. Emergency therapeutic/tectonic keratoplasty was performed in 29 (24.8%) cases, though 13 (44.8%) of them failed at final follow-up. The final corrected-distance-visual-acuity (CDVA) was 1.67&plusmn;1.08 logMAR. Multivariable logistic regression analyses demonstrated increased age, large infiltrate size (&gt;3mm), and poor presenting CDVA (&lt;1.0 logMAR) as significant negative predictive factors for poor visual outcome (CDVA of &lt;1.0 logMAR) and poor corneal healing (&gt;60 days of healing time or occurrence of corneal perforation requiring emergency keratoplasty; all p&lt;0.05). In conclusion, FK represents a difficult-to-treat ocular infection that often results in poor visual outcome, with a high need for surgical interventions. Innovative treatment strategies are urgently required to tackle this unmet need.