Case reports and series: authenticate rare conditions.

Dear Friends,

This issue has a lot to offer in terms of ingenuity and also emphasizes the importance of case reports.

Central corneal thickness (CCT) is an important parameter to be assessed while measuring intraocular pressure (IOP). In fact, IOP has to be corrected in case of CCT before making a diagnosis of glaucoma.[1] Variations in CCT alter the corneal resistance to indentation, and so it is no longer balanced exactly by the tear film surface tension, affecting the accuracy of IOP measurement. A thinner cornea may require less force to applanate, leading to underestimation of the true IOP, while a thicker cornea would need more force thus giving an artifactually high IOP reading. Furthermore, a recent ocular hypertension treatment study reported CCT to be a strong predictor for developing primary open angle glaucoma in patients with ocular hypertension.[2] It also reported that individuals with a CCT of 555 µm or less had 3 times greater risk for developing glaucoma compared with CCT greater than 588 µµm.[2] Although such cut-off values have been devised from many studies, it should be kept in mind that physiological variations in CCT has been noted.[3] Especially, few studies reported changes in CCT during menstruation.[456] But these studies are limited with only few study participants and the difference in the measuring techniques, and so no conclusions can be drawn. Ghahfarokhi et al.[7] in this issue has published a study evaluating the changes in CCT in fifty healthy reproductive women. The authors measured CCT during three phases in all the study participants: Days 1–3, during ovulation time and between days 27 and 32 of the menstrual cycle using ultrasonic pachymeter. A statistically significant increase in the CCT was observed during ovulation time while at the end of the menstrual cycle, it is thinnest. However, the study is limited by the fact that the authors have not looked up directly into the mechanism of this phenomenon. This has to be taken into account while correcting CCT when measuring IOP.

Parry Romberg syndrome is a rare disorder characterized by progressive hemifacial atrophy that is usually unilateral and involves initially the skin, subcutaneous tissue, followed by the deeper tissues such as muscle, cartilage and bone.[8] Although the condition was first described as early as in 1825, only few reports exist in the literature.[9] Usually seen in young adults with the clinical features of a sharply demarcated line between normal and abnormal skin called coup de saber, alopecia, hyper pigmentation of the skin, ipsilateral deviation of mouth and nose and unilateral teeth exposure. Associated neurologic changes include seizures and trigeminal neuralgia.[10] Although ocular changes may occur in 10–35% of the cases ranging from uveitis to enophthalmos, atrophy of the iris and ciliary body have never been reported. Ashwini Kini et al. in this issue have published a case of 16-year-old girl with this syndrome presenting with ocular atrophy. Case reports and case series primarily serve as evidence in the case of rare conditions although the strength of drawing conclusion is considered low. Lin et al. in this issue reported a series of three patients with choroidal metastasis who were administered transpupillary thermotherapy (TPT) and intravitreal bevacizumab. Previous studies evaluated the efficacy of standalone therapies of TPT and bevacizumab, but hardly any exist with the combination.[11121314] The authors found that the combination was effective in containing the tumor growth. In the current milieu of increased prevalence of lung and breast cancers, secondary metastasis in the uvea has been found to be rising, and the result of this study is promising. However, more prospective studies evaluating the cost of various management approaches are necessary before attaining a consensus.

Case report/series are also forms of Evidence based practice, which help authenticate the diagnosis of rare conditions. I urge all practitioners to publish rare cases as reports and series which help a great deal in diagnosis and intervention. In all the Research Methodology workshops conducted by IJO, I have stressed on the importance of case reports and also encouraged practicing ophthalmologists to document their findings and enjoy the joy of publishing.

Regarding the rising cost of health interventions, it is important to implement cost-effective management options especially in India, where the average out-of-pocket expenditure for health is 80%. Kothari et al. in this issue has taken a lead to convert a conventional wired-halogen illuminated indirect ophthalmoscope to a wireless-light emitting diode illuminated indirect ophthalmoscope in less than one thousand Indian rupees. The authors have also tested the same in a total of 29 subjects and found no statistically significant visual acuity loss between both the measurements. As indirect ophthalmoscope is a frequently used instrument by ophthalmologists worldwide and various newer models of the same are expensive, this approach is a welcoming one.

Happy reading!!!