A new polymorphic form of the title compound, C8H8O3, is described in the centrosymmetric monoclinic space group P21/c with Z' = 1 as compared to the first polymorph, which crystallizes with two conformers (Z' = 2) in the asymmetric unit in the same space group. In the crystal of the second polymorph, inversion dimers linked by O-H⋯O hydrogen bonds occur and these are linked into zigzag chains, propagating along the b-axis direction by C-H⋯O links. The crystal structure also features a weak π-π inter-action, with a centroid-to-centroid distance of 3.8018 (6) Å. The second polymorph of the title compound is less stable than the reported first polymorph, as indicated by its smaller calculated lattice energy.
Enucleation and evisceration are the most common surgical procedures that are performed to manage tumor, trauma, and infection. Given the consequences of surgical intervention, the conditions of the remaining eye socket may affect future prosthetic rehabilitation. A custom-made ocular prosthesis can be used to help restore the esthetics and functional defects and to improve the quality of life of patients with such conditions. An assessment must be performed on the prosthetic outcome before rehabilitation. The etiology of defect, type of surgery, condition of the remaining socket, and patient's age should all be considered. This report discusses three different etiological eye defects that have undergone enucleation and evisceration and describes the factors that have a significant role in the esthetic and functional outcome of the prosthesis. This report should serve as a helpful aid for maxillofacial prosthodontists to understand the primary objective of rehabilitating each eye defect and to meet patient expectations.
Eye socket contracture is a well-known late complication of enucleation surgery, and the additional insult of radiotherapy at an early age causes even further fibrosis and scarring of the socket. Management of the contracted socket is challenging, and several methods have been proposed. We report a case of eye socket contracture after enucleation and radiotherapy in which multiple reconstructive procedures failed. The recurrent contracture caused difficulty in housing and retaining the eye prosthesis. We reconstructed the lower eyelid with a facial artery myomucosal flap and nasolabial flap, and the upper eyelid with a Fricke flap following reconstruction of the orbital rims (supraorbital and infraorbital rims with a calvarial bone graft, and further augmentation of the infraorbital rim with a rib bone graft). Cosmesis post-reconstruction was acceptable and the prosthesis was retained very well.
Patients who lost their eyes as results of accidents or diseases (e.g. retinoblastoma) usually underwent enucleation or evisceration. They were then fi tted with ocular prosthesis to prevent collapse of the globe and also for cosmetic effects. Custom made ocular prosthesis is almost unheard of in this country for most hospitals supply ready-made (stock) prosthesis. The cosmetic results of stock prosthesis are often unsatisfactory. Besides being uncomfortable, stock prosthesis may also induce allergic reaction that may lead to papillary conjunctivitis. The Optometry Clinic at UKM started its custom made prosthetic service in 2010. We described here two cases of patients who complained of discomfort with their old stock prosthesis and re-fitted with custom made prosthesis. We also highlight the importance of proper hygiene and maintenance so that ocular prosthesis can be used for as long as possible. This article aims to create awareness among eye care practitioners and showcase the cosmetic benefi ts of custom made ocular prosthesis.
Study site: Optometry clinic, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
Scleral buckle placement is a well-established technique for the treatment of primary rhegmatogenous retinal
detachment. Complications associated with scleral buckle are uncommon and its presentations can be vary. We
report a case of recurrent orbital cellulitis with anterior segment ischemia following a forgotten episode of previous
scleral buckling surgery, presenting with blurring of vision, redness and swelling of the lids. The presence of scleral
buckle was detected by detailed examination and confirmed by orbital imaging. Orbital infection and rubeosis iridis
were successfully treated with scleral buckle removal, intravenous antibiotics and intracameral ranibizumab.
However, the retinal detachment recurred and the visual acuity deteriorated to light perception. There was no further
intervention as the family declined in view of her old age. In cases of recurrent orbital infection, detailed clinical
examination is important to look for evidence of ocular prostheses as a source of infection. Orbital imaging is an
adjunct for making the diagnosis especially in cases where history is unreliable. Anterior segment ischemia due to
scleral buckle responds well to buckle removal with ranibizumab injection.
Retinoblastoma is a rare intraocular malignant tumour more commonly seen in children below five years of age. We presented a rare case of retinoblastoma in an older child. A nine-year-old girl noticed that she had loss of vision OS following a fall at home. Her vision was 6/6 OD and only light perception OS. Examination of the left eye revealed an extensive exudative retinal detachment. Her right eye examination was unremarkable. CT scan showed a left eye intraocular mass with calcification. EUA revealed a mixed endophytic and exophytic mass with extensive exudative retinal detachment. Family members consented to left eye enucleation and histopathological report confirmed the diagnosis of retinoblastoma. Post enucleation, patient is doing well with a prosthetic eye. In conclusion, any unexplained visual loss in children regardless of age warrants a full ophthalmological examination as the possibility of retinoblastoma cannot be ruled out.
A systematic review was conducted in early 2019 to evaluate the articles published that dealt with digital workflow, CAD, rapid prototyping and digital image processing in the rehabilitation by maxillofacial prosthetics. The objective of the review was to primarily identify the recorded cases of orofacial rehabilitation made by maxillofacial prosthetics using computer assisted 3D printing. Secondary objectives were to analyze the methods of data acquisition recorded with challenges and limitations documented with various software in the workflow. Articles were searched from Scopus, PubMed and Google Scholar based on the predetermined eligibility criteria. Thirty-nine selected papers from 1992 to 2019 were then read and categorized according to type of prosthesis described in the papers. For nasal prostheses, Common Methods of data acquisition mentioned were computed tomography, photogrammetry and laser scanners. After image processing, computer aided design (CAD) was used to design and merge the prosthesis to the peripheral healthy tissue. Designing and printing the mold was more preferred. Moisture and muscle movement affected the overall fit especially for prostheses directly designed and printed. For auricular prostheses, laser scanning was most preferred. For unilateral defects, CAD was used to mirror the healthy tissue over to the defect side. Authors emphasized on the need of digital library for prostheses selection, especially for bilateral defects. Printing the mold and conventionally creating the prosthesis was most preferred due to issues of proper fit and color matching. Orbital prostheses follow a similar workflow as auricular prosthesis. 3D photogrammetry and laser scans were more preferred and directly printing the prosthesis was favored in various instance. However, ocular prostheses fabrication was recorded to be a challenge due to difficulties in appropriate volume reconstruction and inability to mirror healthy globe. Only successful cases of digitally designed and printed iris were noted.
A 70-year-old man who suffered from extensive extra and intraoral defects was rehabilitated with a prosthesis using multiple retaining means. The treatment was performed in two parts: externally involving the construction of an episthesis supported only by the remaining intact boundaries of the defect and retained by mini-dental implants and spectacle frame with a modified ear hook; and intraorally by an acrylic resin obturator to restore the function of the hemi-sectioned hard and soft palate. The episthesis was securely retained with minimal movement and/or dislodgment of the prosthesis during function. Multiple retentive techniques may be used to fix heavy external prostheses as an alternative to conventional implants or biological adhesives.
The Department of Oral & Maxillofacial Surgery at Hospital Sultanah Aminah, Johor Bahru started managing patients who lost their eyeballs with ocular prosthesis in 2013. Unfortunately, there was an increasing trend of failed ocular prosthesis from 2013-2015. The failure rate went from 28.6% in 2013 to 40% in 2014 and increased to 44.4% in 2015. Failed ocular prosthesis not only leads to dissatisfied patients but also an increase in cost due to redoing of prosthesis. The objective of this project was to reduce the incidence rate of failed ocular prosthesis. A failed case is when the prosthesis does not pass the issue stage and has to be redone from the beginning. The standard failure rate is 0%, as the average number of cases per year is only about 10 cases. We determined the contributing factors of failed ocular prosthesis by analysing retrospective data from patients’ dental and lab records. This was followed by a self-administered questionnaire on reasons for failed cases which was distributed among the dentists and lab technicians in our department. The contributing factors that were identified included insufficient knowledge or skill of dentist and lab technicians in the construction of the ocular prosthesis, as well as improper screening of new cases which was the main factor of all the failed cases. The strategies for change included improving the process of care by creating a checklist for proper screening of new patients, mentoring of new staff, and continuous training on construction of ocular prosthesis, Fabricated Iris Mould innovation technique and early referral for insertion of eye conformer. The interventions that were implemented reduced the failure rate to 20% in 2016 followed by 0% in 2017, 2018 and 2019. Ongoing efforts are being done to replicate this project in other Oral & Maxillofacial Surgery clinics in Johor.
Anti-glaucoma latanoprost-loaded ocular implants provide prolonged delivery and enhanced bioavailability relative to the conventional eye drops. This study aims at the development and validation of a reversed-phase high-performance liquid chromatography method for quantitative analysis of nanogram levels of latanoprost in the eye, and for the first time, compares the use of fluorescence vs ultraviolet (UV) detectors in latanoprost quantification. The mobile phase was composed of acetonitrile:0.1% v/v formic acid (60:40, v/v) with a flow rate of 1 mL/min and separation was done using a C18 column at temperature 40°C. The fluorescence excitation and emission wavelengths were set at 265 and 285 nm, respectively, while the UV absorption was measured at 200 nm. The latanoprost concentration-peak area relationship maintained its linearity (R2 = 0.9999) over concentration ranges of 0.063-10 μg/mL and 0.212-10 μg/mL for the fluorescence and UV detectors, respectively. The UV detector showed better precision, while the fluorescence detector exhibited higher robustness and greater sensitivity, with a detection limit of 0.021 μg/mL. The fluorescence detector was selected for quantification of latanoprost released from ocular implants in vitro and in porcine ocular tissues. The developed method is a robust, rapid and cost-effective alternative to liquid chromatography-mass spectrometry for routine analysis of latanoprost released from ocular implants.
A vascularized outer-table calvarial bone graft was used for repairing a Posnick type 2 traumatic orbito-frontal bone defect supported by the use of a calcium-based putty (Allomatrix) in a 7-year-old girl. Gaps between the donor and recipient sites were filled with Allomatrix containing demineralized bone matrix particles. Four years later there was a good cosmetic result using an artificial left eye.