James Clarke Rice

Identification of ocular surface squamous neoplasia by in vivo staining with methylene blue

Aim To evaluate the diagnostic accuracy of methylene blue used as a non-invasive in vivo stain to detect ocular surface squamous neoplasia (OSSN). Methods A test validation study was performed according to Standards for the reporting of diagnostic accuracy studies (STARD) guidelines on 75 consecutive patients who presented with ocular surface lesions suspicious of OSSN. Methylene blue 1% was instilled in vivo following local anaesthetic. Stain results were documented photographically and read by an independent observer. Lesions were excised at the same visit and evaluated histologically by pathologists who were blind to the stain results. Sensitivity, specificity, positive and negative predictive values were determined. Results Thirty-three patients had histologically malignant lesions, of which 32 stained with methylene blue, and 42 patients had benign or premalignant lesions, of which 21 stained with methylene blue. Methylene blue had a sensitivity of 97%, specificity of 50% and positive and negative predictive values of 60% and 96%, respectively. Conclusions The topical application of methylene blue is a simple, inexpensive, non-invasive diagnostic test that can be helpful in excluding malignant ocular surface lesions but cannot replace histology as gold standard for diagnosis of OSSN.

Fatal air embolism during endoresection of choroidal melanoma.

PURPOSE To describe a case of intraoperative mortality because of air embolism during resection of a choroidal melanoma by pars plana vitrectomy. METHODS Retrospective interventional case report. RESULTS A 69-year-old man died unexpectedly at the time of pars plana vitrectomy. The operative technique involved the use of high-pressure air (60 mmHg) in the presence of traumatically exposed choroidal vasculature. Autopsy revealed a large air embolus in the right ventricle, which resulted in sudden cardiovascular collapse. CONCLUSION Air embolism is a rare complication of ophthalmic surgery. Infusion of air in the presence of traumatically exposed choroidal vasculature exposes the patient to the risk of air embolism. Ophthalmic surgeons and anesthetists should be aware of the possibility of air embolism during certain ophthalmic procedures, and appropriate intraoperative monitoring should be considered.

The treatment of carcinoma in situ and squamous cell carcinoma of the conjunctiva with fractionated strontium-90 radiation in a population with a high prevalence of HIV

Background This study explores the safety and efficacy of strontium 90 (Sr-90) brachytherapy as the sole adjuvant therapy for carcinoma in situ (CIS) and squamous cell carcinoma (SCC) of the conjunctiva in a high HIV prevalent area. Methods This is a retrospective case review of patients treated with 60 Gray Sr-90 brachytherapy in four divided doses after resection with a 2 mm margin and histological confirmation. Cryotherapy or alcohol debridement was not performed at the time of excision due to limited resources. Two plaque sizes, 8.5 mm and 18 mm, were used. Results Sixty-nine patients were treated and had a median follow-up of 27 months (range 6–127). Thirty-three (47.8%) were HIV-positive. CIS was present in 40.6% and SCC in 59.4%. The surgical margins were positive in 39 (56.5%). Twenty patients (29.0%) were treated with the 18 mm plaque and 49 (71.0%) with the 8.5 mm plaque. Eight (11.6%) patients developed a recurrence at a median of 5 months (range 2–40). Recurrences only occurred in patients treated with the 8.5 mm plaque (p=0.094). There was no significant effect of HIV status, positive margins or staging on the number of recurrences. Treatment side effects were a dry eye in five patients which was successfully managed with topical lubricants, and induced astigmatism of 1 dioptre of cylinder in one patient. Conclusions Sr-90 brachytherapy is safe and effective in preventing recurrences in ocular surface squamous neoplasia in a high HIV prevalent setting. The 18 mm plaque size is superior to the 8.5 mm plaque size.

Brachytherapy and endoresection for choroidal melanoma: a cohort study

Aim To report and compare the outcomes of brachytherapy and endoresection in the conservative treatment of medium sized choroidal melanoma. Methods A retrospective cohort study. Medium tumours were defined as 2.5–10 mm in height and less than 16 mm in the widest diameter. Consecutive patients undergoing brachytherapy at Groote Schuur Hospital were compared with a cohort undergoing endoresection from a national database. Results 148 brachytherapy and 22 endoresection patients were followed for a median of 55.4 and 62.4 months, respectively. Tumours undergoing endoresection were thicker (7.3 vs 4.9 mm, p<0.001, Wilcoxon rank-sum test) and further from the fovea (5.2 vs 3.7 mm, p=0.05, Wilcoxon rank-sum test) than those treated with brachytherapy. Visual acuity of 6/18 or better was maintained in 41% of the endoresection group and 35% of the brachytherapy group. The likelihood of achieving a final visual acuity of better than 2/60 was 22% higher in the endoresection group (risk ratio 1.22, 95% CI 1.02 to 1.28, p=0.034). Rates of local recurrence (18.2% vs 14.9%, p=0.75) and metastases or death (18.2% vs 14.2%, p=0.75) were higher in the endoresection group, and the enucleation rate was lower in this group (4.6% vs 10.8%, p=0.70) but these were not statistically significant. Conclusions The outcomes observed in this small cohort of endoresection patients suggest that endoresection of selected tumours may achieve better visual outcomes than brachytherapy. Rates of local recurrence, enucleation and metastases following endoresection require further research. Local recurrence is likely to be influenced by consolidation treatment methods.

Outcomes of eye injuries with retained intraocular foreign material at Groote Schuur Hospital, Cape Town

Background Retained intraocular foreign body (IOFB) is a specific subgroup of open globe injury which is often preventable with appropriate use of eye protection. We describe the spectrum of injuries resulting in IOFB, outcomes and complications following vitrectomy surgery and context specific risk factors which may influence outcomes at our hospital. Methods Retrospective cohort study of 43 consecutive cases of IOFB that underwent vitrectomy surgery. Results The median age was 34.6 years and 95.3% were male. The presenting visual acuities ranged from 6/6 (LogMAR 0.00) to Perception of Light (PL) with a median of Hand Motions (HM) (Interquartile Range (IQR) 6/24-HM). Hammering metal was the most common cause of injury (44.2%); 72% of injuries occurred while performing premeditated high-risk activities. The foreign body was metallic in 76.7% of cases and penetrated the cornea in 69.8% of cases. Lens injury occurred in 65.1%. The retina was impacted in 36 cases (83.7%), four of which impacted the macula. Macula impact was associated with poor visual outcome (p = 0.049, Fisher’s exact). Four cases (9.3%) had endophthalmitis. The median final visual acuity was 6/24 (IQR 6/9–6/60). Visual acuity improved in 63.4.0%. Ten cases (23.8%) were worse than 3/60. Better presenting vision was associated with better visual outcomes (p = 0.049, Fisher’s exact). The Ocular Trauma Score predicted outcomes well in better prognosis categories but underestimated final visual outcomes in the poor prognosis category. Central corneal scarring contributed to reduced visual outcomes. Conclusion The majority of IOFB injuries are preventable with appropriate use of eye protection. Visual outcomes are better than other causes of open globe injury. Resource constraints contribute to suboptimal final visual outcomes.