Open Access Case study

Multiple Sclerosis Manifested by Paralysis of Cranial VI Pair with Diplopia

Thiago Sande Miguel, Vinicius Sande Miguel, Daniel Almeida da Costa, Maurício Bastos Pereira

Ophthalmology Research: An International Journal, Page 13-17
DOI: 10.9734/or/2021/v15i430218

Aims: To describe a Multiple Sclerosis Manifested by Paralysis of Cranial VI Pair with Diplopia.

Presentation of Case: A.P.R. female patient, 31 years old, has presented diplopia for 04 days. She denied too many symptoms and comorbidities. No eye trauma and previous eye surgery.

Discussion: Multiple Sclerosis (MS) is a chronic, immune-mediated and demyelinating disease of the central nervous system that mainly affects young female adults. About 85% of individuals with MS start the clinical picture in the form of a relapse, and less can open the picture with progressive neurological deficits, although occasional relapses occur during the course of the disease. Eye changes are frequent in MS and are often the first clinical manifestation.

Results: MS is a rare comorbidity and there are no exact and concrete epidemiological studies so far. Studies about eye alterations are also scarce in Latin American countries.

Ocular involvement may be the first sign of MS. Although MS is an uncommon cause of cranial nerve palsies, its frequency increases in young individuals, with a predominance of abducens nerve palsy, as occurred with the patient in the present report, emphasizing the importance of knowing the profile of this disease.

Conclusion: Ocular findings in MS include optic neuritis, retinitis, peripheral vasculitis, ocular motility abnormalities that can manifest as diplopia or nystagmus, and these manifestations should be recognized by ophthalmologists.

Open Access Case study

Stargardt's Disease Diagnosed in Adults: Case Report

Thiago Sande Miguel, Felipe Bekman Diniz Mitleg Rocha, Tais Cristina Rossett, Daniel Almeida da Costa, Maurício Bastos Pereira

Ophthalmology Research: An International Journal, Page 18-26
DOI: 10.9734/or/2021/v15i430219

Aims: To describe a Stargardt disease, (STGD1) is an autosomal recessive inherited disease often associated with mutations in ABCA4 and characterized by the accumulation of autofluorescent lipofuscin deposits in the retinal pigment epithelium (RPE).

Presentation of Case:  J.A.D.L, male, 52 years old, foreman, born in Rio de Janeiro, attends the ophthalmologic consultation complaining of progressive low visual acuity, noticed at around 31 years of age.

Discussion: Stargardt disease is the most common hereditary macular dystrophy, representing 7% of retinal dystrophies. The first and only clinical manifestation is the decrease in central vision, which predominantly starts between six and fifteen years of age.

Methodology: Case report.

Results: Therefore, the referral of young patients with visual complaints without initial abnormalities of the fundus of the eye for ophthalmological evaluation is essential, since the diagnosis of patients at an early stage of the disease is increasingly important with the advent of new therapeutic possibilities.

Conclusion: Although many factors contribute to the phenotype of patients with STGD1, the expression and residual activity of ABCA4 mutants play an important role in determining disease severity.

Retinal thickness and disease duration influence the visual prognosis of patients. Patients with Stargardt's disease have a smaller macular thickness when compared to normal individuals, and this reduction is related to the duration of the pathology. Therefore, OCT is fundamental for the follow-up of these patients, contributing to a better prognostic assessment of the disease.

Open Access Case study

Reverse Straatsma Syndrome – A Case Report

Payal Mukherji, Suchitra Kumari, Neha Shilpy, Vidya Bhushan Sinha

Ophthalmology Research: An International Journal, Page 36-39
DOI: 10.9734/or/2021/v15i430222

Objective: Ophthalmologic signs and symptoms were evaluated in a patient diagnosed with reverse Straatsma syndrome.

Case Presentation: 22 years old male presented to Eye OPD with unilateral diminution of vision of left eye present since childhood. Complete ophthalmologic examination showed anisometropic hypermetropic ambylopia of +8DS/ +3.5DC x 90◦ in LE, correctable to 6/60 and myelinated nerve fibres in LE retina superior to optic disc. The RE after refractive correction of +1.5 DS showed 6/6 vision.

Results: Patient was given full refractive correction of RE and counseled for the condition in LE.

Open Access Original Research Article

Analysis of Dynamic Efficacy Profile of Corneal Cross-Linking: Role of Oxygen and Rate Constants in Type-I and II Processes

Jui-Teng Lin, Yi-Ze Lee

Ophthalmology Research: An International Journal, Page 1-12
DOI: 10.9734/or/2021/v15i430217

Purpose: To explore (theoretically) the key parameters and their influence on the time profiles of photosensitizer (riboflavin), free radicals, singlet oxygen, oxygen and the efficacy of corneal collagen crosslinking (CXL) in both type-I and oxygen-mediated type-II mechanisms, specially the role of oxygen and the initiator regeneration.

Study Design: Numerical solutions of the rate equation of CXL.

Place and Duration of Study: New Taipei City, Taiwan, between October, 2021 and November, 2021.

Methodology: Coupled kinetic equations are derived and numerically solved under the quasi-steady state condition for the 2-pathway mechanisms of CXL. The key parameters explored include (bI, V, Q', K, K',Q,P) and their influence on the time profiles of photosensitizer (riboflavin, C), radicals (R), singlet oxygen(S), oxygen (X) and efficacy (E), parameters of (K,K',Q) define the relative strength of type-I and type-II process. The oxygen depletion profile, X(t), and the associated singlet oxygen, S(t), depend on the parameters of V, Q' and the initial value of oxygen. The coupling strength given by (bI) governs almost all profiles, where b is an effective absorption parameter and I is the UV light intensity.

Results: Our numerical method for CXL dynamic profiles demonstrated the following important features: (i) Type-I and type-II co exit in CXL, in the presence of oxygen. However, there is no type-II when oxygen is depleted or in a condition without oxygen. (ii) Type-I with bimolecular termination, the radical R(t) is a function of [K'(bIgC)]0.5, leading to the steady-state efficacy given by a scaling law of 1/(bI)0.5, in contract to that of type-II which is almost independent to the light intensity. (iii) The depletion rate (2 to 5 minutes) of X(t) is much faster than that of C(t) (10 to 20 minutes), (iv) The pure type-II profile, has a transition point from straight line to saturating curve and matches the depletion point of singlet oxygen S(t). (v) Improved CXL efficacy of type-I and type-II may be achieved by external supply of photoinitiator (riboflavin) and oxygen, respectively.

Open Access Original Research Article

Efficacy Analysis of Corneal Crosslinking (CXL): Comparing Epi-on and Epi-off Procedures

Jui-Teng Lin

Ophthalmology Research: An International Journal, Page 27-35
DOI: 10.9734/or/2021/v15i430221

Purpose: To analyze the factors influencing the corneal crosslinking (CXL) efficacy and comparison of epi-on and epi-off procedures.

Study Design: modeling the efficacy of epi-off and epi-on CXL.

Place and Duration of Study: New Taipei City, Taiwan, between November, 2021 and December, 2021.

Methodology: Solving the rate equations for the CXL efficacy which includes the roles of concentration of the photosensitizer, riboflavin (RF), RF depletion effects, dynamic of light intensity, and the non-uniform distribution of RF in the stroma, or the diffusion depth of RF. Both steady-state and transient state features are explored for the efficacy, crosslink depth (CD) and the effects of epithelium layer for the epi-on situation.

Results: The steady-state efficacy is proportional to the square-root of [RF-concentration] /[light-intensity], The competing factors of reduced RF, F(z), and reduced light intensity in the stroma determine the relative efficacy of epi-on and epi-off. For example, for F(z)<0.5, epi-on is more efficient than epi-off. In contrast, in the transient state (with efficacy <0.6), the efficacy is proportional to the light dose, and therefore epi-on is always less efficient than epi-off. The crosslink depth (CD) has an inverse trend, such that higher light intensity and lower RF concentration lead to deeper CD. The analytic formulas are developed under simplified conditions, in which numerical simulation is required for non-uniform distribution, and when RF depletion are included. Various strategies for improved steady-state efficacy efficacy and crosslink depth for epi-on CXL are explored including the use of higher RF concentration and lower light intensity; enhancing the RF diffusion by an electrode device, or diffusion enhancing medicine. The analytic formulas are compared with measured data.

Conclusion: For the steady-state epi-on is more efficient than epi-off, when the RF reduction factor is less than the light intensity gain factor. In contrast, in the transient state (with efficacy <0.6), the efficacy is proportional to the light dose, and therefore epi-on is always less efficient than epi-off.

Open Access Original Research Article

Demographic Profile of Patients with Corneal Blindness at Tertiary Health Care Centre

Vishal Wagh, Pravin Tidake

Ophthalmology Research: An International Journal, Page 40-47
DOI: 10.9734/or/2021/v15i430232

Objective: To study the etiopathogenesis, age, gender distribution and visual impairment due to corneal blindness in a tertiary health care centre. In addition, to create awareness for eye donation among the population.

Methods: The study was a cross sectional study conducted at a university hospital. Patients who arrived at the outpatient department while the study was ongoing had their demographic profiles recorded. Corneal blindness was defined by presenting a VA 3/60 by corneal disease in the affected eye. The experts made the diagnosis. 56 patients of both gender and age were included in study.

Results: The prevalence of corneal blindness was found to more in men than women were and is more in patients with age >50 and < 10 years. The prevalence is more in rural population than urban among which farmer are most involved

Conclusion: To decrease the burden of the corneal blindness patient in developing countries like India, there is need of educating the population about preventive measures and development and modernisation of ophthalmic centres.