Journal of Ophthalmic and Optometric Sciences

Purpose: To determine refraction and corneal astigmatism using an ophthalmometer and to calculate the difference between the two to obtain the mean internal astigmatism.
Patients and Methods: This study included 45 patients. Inclusion criteria required participants to be 18 years or older with astigmatism. Manifest refraction was measured at least five times per eye using a Topcon RM-8900 autorefractometer and then confirmed by retinoscopy. Patients were subsequently examined with a Topcon Ophthalmometer and the results were recorded.
Results: The mean internal astigmatism values were approximately equal for the right (-0.5333 D) and left eyes (-0.5722 D). The mean amplitude of accommodation values were also similar for the right (9.2333 D) and left (9.0444 D) eyes. No correlation was found between internal astigmatism and amplitude of accommodation.
Conclusion: The mean internal astigmatism values obtained for the right and left eyes were consistent with Javal’s hypothesis, supporting its validity. No significant difference in the distribution of internal astigmatism was observed between the two eyes. Additionally, no correlation was found between internal astigmatism and the amplitude of accommodation.

Purpose: To find out the causes of the non-tolerance of spectacles used among the patients visiting Biratnagar Eye Hospital, Nepal.
Patients and Methods: This prospective cross-sectional study was conducted among patients visiting the optical department of Biratnagar Eye Hospital, Biratnagar, Nepal. Patients of age more than 20 years who fall under the definition of spectacle non-tolerance were included. Patients’ spectacle intolerance was verified based on the tolerance limit criteria by the American National Standards Institute (ANSI Z80.1-2015).
Results:  A total of 8,000 spectacles were prescribed during the 3 months of study period between April to June 2022. Among these prescriptions non-tolerance cases accounted for 104 patients. The mean age of patients was 41.63 ±13.30 year, ranging between 20 and 70 years. From the total population, 61.55% were male. The prevalence of spectacle non-tolerance was 1.3%. The majority of non-tolerance occurred in the 41-50 age group (31.0%). A major cause of non-tolerance to spectacles was dispensing error accounting for 48% of cases, particularly notable among bifocal lens users.
Conclusion: It is crucial to exercise careful consideration when prescribing and providing glasses to patients. Practitioners should eliminate transcription errors completely, as they are unacceptable from a professional standpoint. Opticians should diligently verify all essential parameters for glasses and ensure proper alignment both on and off the face. This meticulous approach serves to reduce intolerance and elevate patient satisfaction with their spectacles.

Refractive errors are among the most common reasons for visiting ophthalmologists and are the leading cause of correctable visual impairment worldwide. Vision can be improved using glasses, contact lenses, and refractive surgeries. Blue control lenses are a new type of lens designed to selectively filter high-energy visible light. Due to the increasing prevalence of digital work, many opticians now prefer prescribing blue control glasses. We encountered four similar cases where individuals, despite having appropriately prescribed glasses and no other identifiable cause for headache, experienced headache caused after using blue light control lenses. Their symptoms resolved after switching to regular anti-reflective lenses. Awareness of potential side effects from blue control lenses is crucial, as preventing headaches can enhance quality of life and avoid unnecessary costs for individuals.

Purpose: To investigate changes in the thickness of different retinal layers following intravitreal injection of bevacizumab in patients with diabetic macular edema (DME) and its association with post treatment vision.
Patients and Methods: Bevacizumab injection was administered three times, four weeks apart. Study of retinal layer segmentation was performed manually only at the beginning of the study and at the final examination (month 6) using the SD-OCT imaging and retinal thickness was recorded in the 1, 3, and 6 mm areas of the central macula and in different quadrants.
Results: A total of 29 eyes from 29 patients were included in the study. The mean retinal thickness in the central macular area decreased from 409 ± 72 microns at the beginning of the study to 315 ± 44 microns at month six (P < 0.001). In the inner ring, the retinal thickness decreased from 410 ± 44 microns to 359 ± 25 microns (P < 0.001). These values in the outer ring were 342 ± 42 microns and 320 ± 31 microns, respectively (P < 0.001).The reduction in thickness in certain retinal layers of the inner and outer retina, along with better baseline visual acuity  (P < 0.001) were positively associated with final visual acuity.
Conclusion: Our study showed that the changes in retinal thickness after intravitreal injection of bevacizumab occurs in both the inner and outer retina, and the reduction in thickness in certain retinal layers along with better baseline visual acuity is positively associated with final visual acuity.

Multiple sclerosis (MS) frequently affects visual system, leading to complications such as contrast sensitivity deficits, visual field abnormalities, pupillary reflex disturbances, and efferent pathway dysfunction. These visual deficits may occur even without a history of optic neuritis. Uveitis and periphlebitis, observed in a subset of MS patients, further contribute to disability and require careful monitoring. Given the high prevalence of visual involvement, a comprehensive ophthalmic evaluation, including visual evoked potential (VEP) and optical coherence tomography (OCT), is essential for early diagnosis and disease monitoring.
Steroids remain the primary treatment for acute MS exacerbations, but they offer no long-term visual benefits and may lead to complications such as central serous retinopathy. Disease-modifying therapies, including natalizumab, fingolimod, and alemtuzumab, are associated with retinal vascular complications and increased susceptibility to opportunistic infections. Early recognition and continuous monitoring of ophthalmic complications in MS are critical for preserving visual function.

A forty-one-year-old man suffering from schizophrenia was referred to Basir Eye Clinic, Tehran, Iran, for visual evoked potential (VEP) testing. His right eye was totally blind, whereas his left eye was barely able to distinguish light. The VEP P100 peak was absent in both eyes. A full workup of the patient revealed that he suffered from central retinal vein occlusion due to antipsychotic drugs.

A 59-year-old male patient was referred to Basir Eye Clinic, Tehran, Iran, for visual evoked potential (VEP) and electroretinography (ERG) of the left eye. The results showed a flat VEP P100 peak and a flat ERG b-wave. Further investigation into the cause of this sudden episode revealed central retinal vein occlusion, which was attributed to acute mental stress.