High vacuum phacoemulsification technique in cataract surgery

Phacoemulsification offers the advantage of cataract removal through a small wound which decreases the surgical complications and enhances rehabilitation. In phacoemulsification corneal endotlielial loss was correlated to duration of ultrasound power used. The longer the duration, the greater is the loss . Increasing the power carries the risk of increasing the insult. While decreasing the power causes less effective cutting power and more stress on capsule and zonules. Vacuum is one of the tools that can be used in phacoemulsification. It can be used as a holding power at probe port for efficient cutting. It also, aspirates soft materials and therefore reduces the need for ultrasound power. To evaluate the use of high vacuum while performing phacoemulsification and to correlate the ultrasonic power needed in relation to the vacuum level. Forty patients with 40 cataractous eyes were enrolled in this study. Their ages ranged between 53 to 65 years with a mean of 59 +/- 6.5 years. Patients were divided into two groups each containing 20 patients [eyes]. Group I underwent phacoemulsification cataract extraction with posterior chamber [PC] foldable acrylic lens using the highest possible vacuum and accordingly lowest possible ultrasound power. Group II underwent traditional phacoemulsification cataract extraction with posterior chamber [PC] foldable acrylic lens. In both groups phacoemulsification was performed in-situ using stop and chop technique. The viscoelastic substance that had been used was sodium hyalurinate [Healon]. Central corneal ultrasound pachymetry was done for all patients preoperatively. Postoperatively; patients were examined weekly in the first postoperative month then after second and third month where central corneal pachymetry was done in each visit. These pachymetric values were used as a sensitive indicator of corneal endothelial physiology. The ultrasound powers and times used in emulsification were recorded during surgeries to correlate them to the vacuum. Postoperatively; the corneal thickness had been increased in all patients due to corneal edema. This corneal edema continued to improve during the 3 months follow up period. The corneal edema postoperatively was less in group I than in group II. With the high vacuum; the ultrasound power needed was less that that needed with traditional vacuum levels. The ultrasound energy [Power x Time] was inversely proportional to the vacuum used. From our study we can conclude that using the highest possible vacuum while doing phacoemulsification is a good tool that allows the use of lower ultrasound power. This lower ultrasonic power is safer for the corneal endothelium. Thus; the final visual outcome of the phacoemulsification cataract surgery can be refined

Clinico-pathological study of 22 eyes of retinoblastoma in Sharkia governorate

This work aimed at studying the natural history of retinoblastoma [Rb] in our locality in addition to its potential histogenesis and prognostic markers .A series of [22] eyes with Rb of [19] patients were studied clinically [using indirect ophthalmoscopy with scleral indentation under general anaestheisa, ultrasonography and CT scanning] and histopathologically [using Hx and E stained sections, special stains and immunohistochemistry for neuron specific enolase [NSE]]. Metastatic disease work up was done during follow up period of at least 12 months.All cases were diagnosed in children less than 5 years of age [mean of 31 months for unilateral cases and 18 months for bilateral cases]. Male to female ratio was 1.2:1. Leukocoria and strabismus were most common mode of presentation [64%], [18%] respectively. Hx and E stained sections revealed that [75%] of eyes showed the trabecular pattern and [50%] showed the glomeruloid pattern. Homer Wright [H.W.] rosettes were seen in various degrees in all tumours [abundant in well differentiated tumour and few in poorly differentiated one]. Rb cells demonstrated varying degrees of positive or negative reaction to NSE, most Flexner-Winsterstenier [F.W.] and H.W. rosettes being positive and Fleurettes weakly positive or negative. Metastatic disease of retinoblastoma was related mainly to optic nerve invasion reaching the resection margin [75%] and poor tumour differentiation [80%].Regarding the natural history of retinoblastoma in this study, leukocoria and strabismus are the most common modes of presentation. Cases with bilateral lesions tend to present at younger age group. Immunohistochemical findings suggest that Rb is a primitive stem cell neuroectodermal tumour with capability for differentiation in both neural and neuroglial directions. The two main prognostic markers for metastatic disease are optic nerve invasion reaching the resection margin and poor tumour differentiation

Goniotomy in comparative study with trabeculotomy AB externo for treatment of primary congenital glaucoma

Thirty eight eyes of 22 patients with primary congenital glaucoma were treated with goniotomy under direct visualization with goniolens [17 eyes] and with trabeculotomy ab externo [21 eyes] between May 1982 and February 1988. A single goniotomy could control the intraocular pressure in seven eyes, [41.2%], while a single trabeculotomy was successful in seventeen eyes, [81%]. Two goniotomies were successful in six eyes, [35.3%] while two trabeculotomies were successful in two eyes, [9.5%]. Three goniotomies were successful in one eye, [5.9%]