Medical hypothesis discovery and innovation in ophthalmology

Editorial, No Abstract

Background: This study investigated the effect of instilling a single drop of non-preserved cationic oil-in-water ophthalmic emulsion (Cationorm®) on the lower (LTM) and upper tear meniscus (UTM) parameters of normal eyes.
Methods: In this prospective, single-center, non-randomized, controlled pilot study, optical coherence tomography was used to estimate the UTM and LTM height, depth, and cross-sectional area in participants without a history of dry eye disease. In the right eye (study eye), we instilled one drop of Cationorm® in the lower conjunctival sac. Scans of the tear menisci were acquired at baseline, before the instillation, and at 5, 15, and 30 min thereafter. Control scans of the left eye (control eye) were obtained at the same timepoints. The tear meniscus parameters of the study eye were compared with the control eye at each timepoint.
Results: Twenty subjects (11 male and 9 female; mean ± standard deviation of age: 37.8 ± 10.9 years) were included in the study. Compared to the control eye, instillation of a single drop of Cationorm® resulted in significantly higher LTM parameter values and a higher UTM cross-sectional area up to 30 min after instillation (all P < 0.05). The UTM height and depth were significantly greater in the study eye than in the control eye up to 5 min (P < 0.001 and 0.007, respectively) and 15-min (P = 0.045, and 0.002, respectively) after Cationorm® instillation. In the study eye, Cationorm® resulted in a significant increase in LTM parameter values up to 30 min post-instillation (all P < 0.001). The UTM height was significantly greater up to 15 min post-instillation than at baseline. The UTM depth and area increased significantly from baseline to 5 min after instillation (P = 0.043, and 0.002, respectively).
Conclusions: Cationorm® seems to have a prolonged residence time on the ocular surface of healthy subjects as indicated by LTM parameters and to a lesser extent by UTM parameters.

Background: This study was conducted to investigate ocular biometry parameters in cataract surgery candidates in northern Tehran, Iran using OA-2000 biometry device.
Methods: In this cross-sectional study, values of ocular biometry parameters, including axial length (AL), anterior chamber depth (ACD), mean corneal curvature (mean K), lens thickness (LT), corneal astigmatism (CA), and white-to-white (WTW) of 818 eyes with cataracts, were measured using the OA-2000 biometry device (Tomey, Nagoya, Japan). The participants were divided into six age subgroups, in 10-year intervals. Finally, the values of the biometry parameters were calculated, and the trend of changes was examined for both age and sex subgroups.
Results: The mean± standard deviation (SD) of age of the participants was 63.82 ± 13.25 years. Mean ± SD of biometry parameters were as follows: AL, 23.36 ± 1.55 mm; ACD, 3.09 ± 0.40 mm; LT, 4.45 ± 0.55 mm; mean K, 44.51 ± 1.72 D; CA, 1.06 ± 0.94 D; and WTW, 11.81 ± 0.45 mm. Most of the parameters showed significant age-related changes in the total population. There was an increase in LT (P < 0.001) and mean K (P = 0.001), as well as a decrease in AL (P < 0.001) and ACD (P < 0.001) with age. Moreover, AL had a negative negligible correlation with LT (r = -0.24, P < 0.001) and mean K (r = -026, P < 0.001), as well as a weak positive correlation with ACD (r = 0.44, P < 0.001).
Conclusions: Our study revealed that the mean values of most biometric parameters varied across age and sex subgroups. Moreover, most of the parameters showed significant age-related changes in the total population.

Background: To report the prevalence of acquired symptomatic external punctal stenosis (EPS) in a tertiary referral center in Kuwait, and to study the associated risk factors, etiologies, and management outcomes.
Methods: This prospective interventional hospital-based study was performed at the Farwaniya governmental hospital in Kuwait between November 2018 and November 2019. All patients were referred to the oculoplastic clinic with symptomatic epiphora, age > 18 years, epiphora Munk score equal or more than 0, tear film meniscus equal or more than 2 mm, and punctum with a grade equal or less than 2 (smaller than normal size, but recognizable) were included. Exclusion criteria were congenital causes of epiphora, previous eyelid surgeries, and traumatic or neoplastic causes of punctal or canalicular obstruction.
Results: A total of 418 patients with symptomatic epiphora, who were referred to our oculoplastic clinic, were enrolled in our study. The prevalence of EPS was 70.3%. Examination of the puncta revealed different shapes, including tangential, pinpoint, elevated, slit-shaped, horse shoe-shaped, and membranous puncta, with the tangential type accounting for the greatest proportion (65.3%). Bilateral punctal stenosis was observed in 206 patients (70.1%) and unilateral involvement in 88 patients (29.9%). Dilatation and syringing were performed for all puncta upon diagnosis, and repeated dilatation was performed for 225 puncta (32.7%). Placement of a Mini-Monoka tube was performed in 11 puncta (1.6%).
Conclusion: EPS was a common cause of symptomatic epiphora in our study. Aging and female sex were identified as common risk factors. Most etiological factors of EPS were associated with a pathophysiological inflammatory mechanism. For exact estimates of its prevalence, a population-based study is necessary in future.

Background: To compare the short-term anatomical and functional outcomes of, as well as patient satisfaction with, lacrimal stenting and three-snip punctoplasty for the treatment of punctal stenosis or occlusion.
Methods: In this open-label, randomized clinical trial, we included 50 eyes of 30 patients diagnosed with punctal stenosis or occlusion. They were randomly allocated to two groups of 25 eyes each, using central telephone randomization. Group A underwent a lacrimal stenting procedure and was subdivided into two subgroups: Group A1 (13 eyes) received polyvinylpyrrolidone-coated perforated punctal plugs, and Group A2 (12 eyes) received closed intubation using a bicanalicular silicon tube. Group B included 25 eyes that underwent three-snip punctoplasty. All eyes were examined after 1 day, 1 week, 1 month, 3 months, and 6 months. Postoperative anatomical success assessing the punctum size, functional success using the fluorescein disappearance test, and patient satisfaction based on epiphora scoring were recorded.
Results: Both study groups were comparable in terms of sex and age distribution. Compared to Group B, Group A had a significantly larger punctum size at one, three, and 6-month postoperatively (P = 0.009, 0.01, and 0.02, respectively). The difference in FDT results was significant between the two groups at all follow-up visits (P = 0.008, 0.0001, 0.003, and 0.002, at postoperative one week, one-months, three-month, and six-month, respectively). Likewise, patient satisfaction was significantly different between both groups at all follow-up visits (P = 0.007, 0.001, 0.005, and 0.002, at postoperative one week, one-months, three-month, and six-month, respectively).
Conclusions: Lacrimal stenting is an effective method for the treatment of punctal stenosis or occlusion. Overall, the FDT results and patient satisfaction outcomes were significantly better.

Background: The most frequent primary ocular malignancy in the western world is the uveal melanoma. While it mainly affects Caucasians, it is extremely uncommon among non-Caucasians. Continuous improvement in therapies for local treatment has allowed sparing of the eye, although this approach apparently does not improve survival. The present review aimed to explain different radiotherapy (RT) methods and compare the pros and cons of each method, along with the main complications that may be encountered in the treatment of uveal melanoma.
Methods: Relevant papers published between September 2009 and January 2021 were retrieved, reviewed, and screened. Four databases, including PubMed, MEDLINE, Google Scholar, and GeneCards, were searched for this purpose.
Results: Forty-one relevant articles were identified. Based on the selected papers, we highlighted the advantages and disadvantages of the different RT methods that have allowed sparing of the eye, even though they have not, as yet, improved survival. We listed a detailed comparison between therapies that allow an educated choice among the different available RT methods.
Conclusion: The choice of uveal melanoma management is determined by the location of the tumor and volume of the extraocular extent. At present, there is no gold standard for the management of all ocular melanomas, and each case should be approached individually. Therefore, classification is a valuable prognostic tool. Many cases in cT3-4 classification categories are treated by primary enucleation and conservative treatment follow-up, while in cT2 and most cT1 classifications (i.e., 3.1–6.0-mm tumor thickness), several forms of RT are used.