The Stiles—Crawford Effect of the First Kind (SCE I): Studies of SCE I in an Aniridic Observer

Perception ◽  
1986 ◽  
Vol 15 (6) ◽  
pp. 777-784 ◽  
Author(s):  
Jay M Enoch ◽  
Vasudevan Lakshminarayanan ◽  
Shinichi Yamade

The Stiles—Crawford effect of the first kind (SCE I), discovered in 1933, represented a major breakthrough in our understanding of retinal physiology and the modern beginning of the science of photoreceptor optics. The current status of knowledge in this area is briefly reviewed. A study is presented of a white adult female observer with aniridia, clear media, only traces of nystagmus, rather good visual acuity, and good fixation. It is shown that this individual exhibits approximate alignment of her photoreceptors with the center of the retinal sphere, clear evidence of side lobes on functions, and surprisingly steep SCE I functions. The implications of these findings are considered.

2018 ◽  
pp. 79-82
Author(s):  
Van Minh Pham ◽  
Van Nam Phan ◽  
Thi Thu Nguyen

Objectives: To investigate the clinical characteristics of cataract patients with small pupils and to evaluate the result of cataract surgery on the eye have small pupils by phacotechnique. Subjects and methods: Descriptive study, prospective, uncontrolled interventions. Sample selection. The sample size of 70 patients with 70 eyes of cataracts with small pupils was treated by phaco technique and intraocular lens implant within posterior chamber. Follow up to 3 months. Results: 70 eyes, the percentage of men and women was not different from 54.2% (38 male) compared to 45.8% (32 female). The mean age was 80 ± 8.74, from 58 to 99 years. The disease was mainly found in the age group over 70 years old with over 80% (51.5%). Visual acuity before surgery was very poor under 3m CF (count finger) for 68.6% (48/70). Visual acuity over 1/10 was only a small amount with 2.8% (2 eyes). Pseudoexfoliation was the most common reason complications of mydriasis with 32/70 eyes (45.7%) and 22/70 eyes (31.4%) for age. The preoperative pupilarysizewas mostly small with 63/70 eyes (90.0%), non-dilated pupils (7/70 eyes) (10.0%). Average pupil size was 3.34 mm (2 - 4mm). Iris condition: iris atrophy 20/10 eyes (28.6%), iris synechiae 11/10 (15.7%), irregular iris muscle with 51, 4% and good iris muscle accounted for 48.6%. Grade of cataract: Grade III: 31/70 eyes (44.3%), Grade IV: 32/70 eyes (45.7%), Grade II: 5/70 eyes (7.1%) and V:2/70 eyes (2.9%). Pupil expander technique: OVD injection with 42/70 eyes (60%), using iris hook with 23/70 eyes (32.9%). Pupillary size before and after intervention has changed from 3.7mm to 4.48mm. Conclusions: Iris expander techniques have been shown to have good dilated pupils: 60.0% OVD injection, iris hook was 32.9%, other methods 7.1% One-week visibility of good visual acuity was higher than that of postoperative one day (12.2%) and increased at 1 month and 3 months (20.0%). Very good visual acuity was not available and low vision group was 1.4% after 3 months. Key words: cataract surgery; phacoemusification, small pupil


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiao-ling Jiao ◽  
Jun Li ◽  
Zhe Yu ◽  
Ping-hui Wei ◽  
Hui Song

Abstract Background To compare visual performance between the iris-fixated phakic intraocular len (pIOL) and implantable collamer len (ICL) to correct high myopia. Methods Twenty-four eyes underwent iris-fixated pIOL implantation and 24 eyes underwent ICL implantation. At the 6-month follow-up, the best-corrected visual acuity (BCVA) and uncorrected distance visual acuity (UDVA) were compared between the iris-fixated pIOL and ICL groups. The objective scatter index (OSI), modulation transfer function (MTF) cutoff, and ocular aberrations were performed to evaluate postoperative visual quality between the two groups. Results No significant difference was found in UDVA, BCVA, and spherical equivalent between the iris-fixated pIOL and ICL groups (P > 0.05). Six months after surgery, the following values were significantly higher in the ICL group than in the iris-fixated pIOL group: MTF cutoff, strehl ratio and optical quality analysis system values at contrasts of 9 %, 20 %, and 100 % (P < 0.01). The OSI in the iris-fixated pIOL group was higher than in the ICL group 6 months after surgery (P < 0.01). All high-order aberrations were slightly more severe in the iris-fixated pIOL group than in the ICL group 6 months after surgery, although only trefoil (P = 0.023) differed significantly in this regard. Conclusions Both iris-fixated lenses and ICLs can provide good visual acuity. ICLs confer better visual performance in MTF-associated parameters and induce less intraocular light scattering than iris-fixated pIOLs.


Author(s):  
Victor Duque ◽  
Carolina de la Pinta ◽  
Ciriaco Corral ◽  
Carmen Vallejo ◽  
Margarita Martin ◽  
...  

Abstract Introduction: Choroidal metastases are the most frequent intraocular secondary tumours, with a prevalence of 2–7% according to the literature. Our aim was to review a clinical case of choroidal metastasis. We present a case of a 63-year-old male patient diagnosed in 2018 with lung adenocarcinoma cT4N0M1. The patient had three metastases in the brain, which were successfully treated with radiosurgery (RS). The patient was treated with chemotherapy with pemetrexed–cisplatin schedule. Five months after diagnosis, the patient presented with decreased vision in the right eye. After ophthalmologic evaluation, he was diagnosed with a right choroidal metastasis, which was treated with external beam radiotherapy with 20 Gy in five fractions, resulting in improved visual acuity and a complete clinical and radiological response. The patient took part in a clinical trial that continued with systemic chemotherapy. Twenty-two months after radiotherapy to the eye, the patient has good visual acuity without any side effects. Conclusions: Choroidal metastasis treated with radiotherapy achieves good local control, with limited side effects, allowing an improvement in visual acuity and consequently, an improvement in the patient´s quality of life.


Eye ◽  
2019 ◽  
Vol 34 (6) ◽  
pp. 1108-1115
Author(s):  
Kieu-Yen Luu ◽  
Mutaal M. Akhter ◽  
Blythe P. Durbin-Johnson ◽  
Ala Moshiri ◽  
Steven Tran ◽  
...  

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