The Marcus Gunn phenomenon. A review of 71 cases

We have reviewed the clinical findings, natural course, pathologic observations, and management of 71 patients with the Marcus Gunn phenomenon. We found individuals with this syndrome to have a significant incidence of amblyopia (59%), double elevator palsy (25%), anisometropia (25%), and superior rectus muscle palsy (23%). Long-term follow-up did not reveal a case that improved with age. In most patients requiring surgery, we recommend a unilateral levator excision on the affected side plus a bilateral frontalis suspension.     

Cadaver dissection for oculoplastic procedures: A beginner’s guide

The purpose of this article is to form a basic guide for beginning the cadaver dissection training programs focused on oculoplastic surgical procedures. Ours was a collaborative study between the departments of Ophthalmology and Anatomy in a tertiary care teaching institute. We formed a step-wise approach to begin the cadaver dissection focused on the oculoplastic surgical procedures. The basics of cadaver procurement, processing, and preparation for dissections were described. The operative requirements of trainees, surgical handling of cadavers, and basic oculoplastic surgical steps were discussed. The types of embalming (cadaver preservation process) and steps have been described in detail. We have emphasized the preoperative discussion about the proposed dissections using standard teachings and skull models for easier understanding. Additional helping tools like soft embalming and injectable substances for better intra-dissection understanding (intra-arterial, intravenous and orbital injections) have been described. Post-dissection cadaver handing and soft-tissue disposal protocols have also been described. Overall, the cadaver dissections provide holistic surgical learning for the residents, specialty trainees, and practitioners. This article may act as a basic step-wise guide for starting the cadaver-based oculoplastics lab dissection in various institutes and workshops.     

Effect of complicated ocular surgery in stress-related parameters: A novel outlook into surgeon’s health

Purpose:To assess the stress-related physiological parameters of ophthalmic surgeons during complicated cataract surgery and compare them with uncomplicated routine cataract surgery.Methods:In this cross-sectional observational study, 110 patients of various types of cataract were divided into two groups: Group 1 included 55 patients with simple cataract (Grade ≤3) with no ocular or systemic comorbidities, whereas Group 2 included 55 patients with complicated cataracts (Grade >3) and ocular/systemic comorbidities. All patients underwent phacoemulsification with intraocular lens implantation in the right eye only. The outcome measures were systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), and saturation of peripheral oxygen (SpO₂).Results:The average SBP, DBP, MAP, and HR were significantly higher in the surgeon operating Group 2 (complicated cataract) compared with Group 1 (uncomplicated cataract; P < 0.05). The average SBP of the surgeon while operating Group 1 patients preoperatively and postoperatively was 125.42 ± 2.49 mmHg and 122.45 ± 2.10 mmHg, respectively, whereas in Group 2, the average SBP of the surgeon taken preoperatively and postoperatively was 145.98 ± 3.80 mmHg and 137.44 ± 3.45 mmHg, respectively (P < 0.05). The surgeon’s SpO₂ showed no significant difference between the two groups.Conclusion:There is a significant level of increase in stress-related parameters of operating surgeons while doing complicated cataract surgery.     

Assessment of retinal manifestations of Parkinson’s disease using spectral domain optical coherence tomography: A study in Indian eyes

Purpose:To assess the retinal manifestations of Parkinson’s disease using optical coherence tomography.Methods:A prospective case-control study comparing 30 eyes from 15 patients with Parkinson’s disease and 22 eyes from 11 healthy age-matched controls. Total macular subfield thickness and the thickness of the ganglion cell layer, nerve fiber layer, and peripapillary retinal nerve fiber layer were measured with spectral-domain optical coherence tomography (SD-OCT).Results:The mean age of PD patients was 68.4 years ± 10.64 (range: 46–82) and in the control group was 66.36 ± 5.22 (range: 64–68). The average disease duration in patients with PD was 6.7 ± 2.8 years (range: 2–10 years). The mean best-corrected visual acuity in PD was 20/26 and 20/20 in controls, with P = 0.0059, which was significant. Significant difference was also found in the contrast sensitivity between both groups. Structural differences in the central macular thickness (P = 0.0001), subfield thicknesses in the superior (P = 0.003), inferior (P = 0.001), nasal (P = 0.004), and temporal subfields (P = 0.017) was seen. Severe thinning of the ganglion cell layer was seen in PD patients (P = 0.000) as well as of the nerve fiber layer (P = 0.004). Peripapillary retinal nerve fiber thickness measured showed significant thinning in superotemporal (P = 0.000), superonasal (P = 0.04), inferonasal (P = 0.000), inferotemporal (P = 0.000), nasal (P = 0.000), and temporal quadrants (P = 0.000).Conclusion:Visual dysfunction was observed in patients with PD along with structural alterations on OCT, which included macular volumes, ganglion cell layer, and peripapillary retinal nerve fiber layer.     

Different faces of the white cataract: A phaco surgeon’s perspective

Purpose: To develop a system of categorizing white cataracts so that the salient features, as would be pertinent to phacoemulsification surgery, could be recognized pre-operatively. Methods: Patients with total cataracts were carefully evaluated using slit-lamp biomicroscopy and slit-lamp photography. An attempt was made to determine whether pre-operative evaluation could ascertain the presence or absence of features of these cataracts that often cause surgical difficulties, namely, increased intralenticular pressure (ILP), milky cortex and brown nuclear colour. Results: Using a standardized method of biomicroscopic evaluation, it was found that the status of the ILP, cortex and nuclear colour could be determined consistently. Surgical strategies based on such a system of categorization has permitted white cataracts to be consistently managed using phacoemulsification. Conclusions: Systematic pre-operative evaluation and categorization of white cataracts based on the ILP, status of the cortex and nuclear colour can permit proper surgical planning and successful management of such cases with phacoemulsification.     

The Differential Diagnosis of Descemet's Tears (Haab's Striae) and Posterior Polymorphous Dystrophy Bands: A Clinicopathologic Study

Band-like structures, clinically similar to Haab's striae, occur in posterior polymorphous dystrophy (PPMD) and are often confused with them. The difference in clinical appearance based on difference in histopathology allows a clear differentiation. The edge of Haab's striae are thickened, curled, and secondarily proliferate Descemet's membrane, while the area between the edge is thin and smooth. Posterior polymorphous dystrophy bands are the exact opposite. The band is a thickening of Descemet's membrane between the edges with thinner, more normal Descemet's membrane outside of them. PPMD bands may be associated with typical vesicles or appear as the only sign of dystrophy, even in the eyes of patients with a known family history.     

Reduction of negative afterimage duration in Parkinson’s disease patients: A possible role for dopaminergic deficiency in the retinal Interplexiform cell layer

Dopaminergic deficiency may affect Parkinson’s disease patients (PD) in the central as well as the peripheral tissues. In the retina, the neuromodulatory role of the dopaminergic Interplexiform cell layer (IP) plays a major role in the retinal light adaptation and may account for the duration of the negative afterimage. Here we present results showing a significant reduction of negative afterimage duration in PD patients. This supports the hypothesis that the retinal dopaminergic system may be the main cause for the long duration of negative afterimage. We suggest that the observed reduction of afterimage duration is due to possible dopaminergic deficiency in patients with Parkinson’s disease.